MiniTrainerSchool
For the MicroPLC from Lovato Electric
Basics of Ladder Diagram and Function Block Diagram programming with
the Lovato software LRXSW
with many practical exercises on Lovato-MiniTrainer
Sil o / Tan k
FBD1 4
I1
Start/Stopp
PWM
Q1
M
Silo / tank
Voll
Zeitrelais T1
Time rela y T1
LAD4
I2 Start
Enable
Q3
T01
Enable
Output
I4
Q2
MOD E
Reset
IA1
LR D 12
LR D12
2
This exercise book serves as an introduction to the world of MicroPLC
LRD12 and LRD20 of Lovato Electric.
It provides a modern small controller that offers many ways to implement a customercentric automation.
Thanks to the various programming languages the LRD… provides something for
everyone. Along with the MiniTrainer, it offers an ideal practice and learning platform
for education and training.
In this exercise book, the basic building blocks of the ladder diagram and function
block programming can be learned with many training examples.
Of course, individuals are free to reshape the exercises or expand.
On the enclosed CD there is a proposed solution offered to each exercise. The
exercise cards for the MiniTrainers are enclosed in two versions. On one hand, the
Lovato-MiniTrainer with the LRD12 and on the other hand for the LovatoMiniTrainerXL with the LRD120, with more I / O points.
Lovato Electric GmbH (Germany)
Im Ermlisgrund 30, 76337 Waldbronn
Tel.: +49 (0) 72 43.76 69 37-0
Fax: +49 (0) 72 43.76 69 37-9
E-Mail: info@lovatoelectric.de
Web-Site from Lovato-Electric: www.lovato.co.uk
Author: Klaus Machalek
1 Edition 2014 (02/14)
All rights, including translation, are reserved. No part of this book may be reproduced in any form
(print, photocopy, microfilm or any other process) without the written permission of the author or
processed using electronic systems, duplicated or distributed. Of these, which expressly referred to in
§ 53, 54 of the Copyright Act except the cases are not affected.
3
Table of Contents
1. Hardware construction
1.1 Exercise equipment
1.2 Technical data of the exercise equipment
1.2.1 MicroSPS: LRD12TD024
1.2.2 MicroPLC: LRD20TD024
1.3 Lovato-MiniTrainer
1.3.1 Assignment of inputs and outputs on the Lovato-MiniTrainer
1.4 Lovato-MiniTrainerXL
1.4.1 Assignment of inputs and outputs on the Lovato-MiniTrainerXL
1.5 Selecting the programming software
7
7
7
7
8
8
9
9
10
11
2. Ladder diagram (LAD)
2.1 circuit diagram window
2.2 Creating a circuit diagram
2.3 Series circuit
2.4 Parallel circuit
2.5 Digital outputs Q/Y and markers M/N
2.6 Boolean algebra as a basis
2.6.1 Logical combinations in the LAD Editor
2.6.1.1 AND-operation
2.6.1.2 OR-operation
2.6.1.3 AND- before OR operation
.
2.6.1.4 OR before AND operation
Exercise: Basic circuits with the LAD Editor: LAD 1a / LAD 1b / LAD 1c
2.6.1.5 Latching
Exercise: Latching: LAD2, LAD3
2.6.1.6 Priority processing - dominant
2.7 Simulation
2.7.1 Simulation on the virtual controller
2.8 Der Online-Test
2.8.1 Coupling
2.8.2 Program transfer
2.9 Time relay (timer) T
2.9.1 Configuration window of time relay (timer)
2.9.2 Setpoint input at time relay
2.9.3 Presentation of the timer in the circuit diagram LAD
2.9.4 Display of the timer on the display of LRD…
2.9.5 Change the setpoint on display?.
Exercises: Time Relay T: LAD4, LAD4a, LAD4b, LAD5a, LAD5b, LAD6, LAD7
2.10 Differential Instruction D
2.11 Counter C
Exercises: Counter C: LAD8, LAD8a, LAD8b, LAD9
2.12 Shift register S01
Exercises: shift register S01:LAD10, LAD11,
2.13 Analog comparator G
Exercises: Analog comparator G: LAD12, LAD13,
2.14 Real Time Clock R
Exercise: Real Time Clock R : LAD14
2.15 Arithmetic blocks AS (ADD / SUB) and MD (MUL / DIV)
Exercise arithmetic AS: LAD15
2.16 Data register DR
Exercise: Data register DR: LAD9a
2.17 Multiplexer MX
12
15
15
17
17
18
19
20
20
21
22
23
24
25
26
27
28
29
30
30
31
32
32
34
35
35
36
37
39
40
42
43
44
45
46
47
48
49
50
51
51
52
4
2.18 Text display H
Exercise: Text display H:LAD16
2.19 Comments for coil and contacts
2.20 Headlines and comments in the Ladder Diagram
53
55
56
57
3. Function block diagram FBD
58
3.1 Creating a function block diagram
3.1.1 draw connections
3.2 Logic sets in the FBD-Editor
3.2.1 AND operation
3.2.2 AND NOT-operation (NAND)
3.2.3 OR operation
3.2.4 AND before OR operation
3.2.5 OR before AND function
3.2.6 OR-NOT operation (NOR)
3.2.7 Exclusive-OR (XOR)
Exercises: Logic blocks: FBD1a, FBD1b, FBD1c
3.2.8 Latching function
Exercise: latching function:FDB2a, FDB2b,
60
61
62
62
63
64
65
66
67
68
69
70
71
3.3 Selection menu of the Function Blocks
3.3.1 Timing relay T
3.3.2 Pulse relay
Exercise: Timer relay: FBD3, FBD4a, FBD5
3.3.3 Counter C
Exercise: Counter: FBD6a, FBD6b, FBD6c, FBD7a, FBD7b
3.3.4 Shift register S01
Exercise: Shift register: FBD8a, FBD8b
3.3.5 Analog comparator G
Exercise: Analog comparator: FBD9a, FBD9b, FBD9c
3.3.6 Multiplexer MX
Exercise Multiplexer: FBD10
3.3.7 Boolean function BL
Exercise Boolean function BL: FBD11, FBD12
3.3.8 Pulse-width modulation (PWM) P
Exercise PWM: FBD13, FBD13a, FBD14
3.3.9 Text H
3.3.10 Display backlight
72
72
74
75
76
78
79
79
80
81
82
82
83
83
85
85
87
87
4. Useful information
88
5
Contents of the CD
Solutions
In LADDER diagram (LAD)
in Function block diagram (FBD)
6
1.
Hardware construction
1.1
Exercise equipment
Lovato Electric GmbH, the manufacturer of MicroPLC LRD12 and LRD20, offers a wide
range of different devices. Starting on the number of input and output points of extensibility to
the different supply voltages.
In this basic course, the devices LRD12 and LRD20 will apply. Once the low cost LRD12 with
the small Lovato-MiniTrainer and another with the LRD20 and the Lovato-MiniTrainerXL for
more inputs and outputs. Thus, both versions offer a simple and inexpensive way to
implement the exercises here used in the book and also to supplement.
1.2
Technical data of the exercise equipment
1.2.1 The MicroPLC LRD12TD024
This MicroPLC provides eight digital 24 VDC inputs in addition to the 24 VDC supply. Of
these, the inputs A1 and A2 can be alternatively used as analog inputs.
8 inputs 24 VDC
Power supply 24 VDC
A1 and A2 digital and
alternatively usable as
analog inputs 0 ... 10V
The display offers the
representation of LAD, FBD and
text.
Cursor key activated as
Z inputs
USB interface to
PC
4 relay or 4 transistor
outputs
Figure 1.1 LRD12TD024
Note:
For the MiniTrainer can either be used the LRD12TD024 with 4 relay- or 4 transistor outputs.
7
1.2.2 MicroPLC: LRD20TD024
Firstly, this exercise utilises the larger design
controller. This makes it possible to use more
inputs and outputs and thus to make the exercise
offer interesting and varied. The MiniTrainer now
has the designation Lovato-MiniTrainerXL.
Preferably, the transistor variant LRD20TD024
should be used, that way you can also use the
PWM functionality better.
Figure 1.2 LRD20TD025
1.3 Lovato-MiniTrainer
Figure 1.3 Lovato MiniTrainer
8
1.3.1 Assignment of inputs and outputs on the Lovato-MiniTrainer:
I9 IA
Figure 1.5 I/O assignment of LRD12
Figure 1.4 MiniTrainer simulation field
1.4 Lovato-MiniTrainerXL
The MiniTrainerXL offers in addition to the 8 latching / momentary switches (I1 to I6 / I9 and
A1) or 2 push buttons (red) as the changer inputs I7 / I8 and IB / IC operate. They are as
shown in the sketch, wired:
I7
I8
IB
IC
The NC I8 and IC can be switched
off via the slide switch. Thus all
inputs via the interface connector
are available and have no default
Latching/momentary
switches
24 VDC-power
supply
Figure 1.6 addition button on the Lovato-MiniTrainersXL
By using the buttons X1 - X4 as real wire break simulations, start-stop functions can be
implemented.
9
1.4.1 Assignment of inputs and outputs on the Lovato-MiniTrainerXL:
I9 IA IB IC
Figure 1.7 MiniTrainerXL
simulation field
Figure 1.8 I/O assignment of LRD20
Lovato-MiniTrainer XL
Figure 1.9 Lovato-MiniTrainerXL
10
1.5
Selecting the programming software
The first part of this book deals with the ladder diagram programming. In the second part of
the function block is handled.
The software offers comfortable implementation of control and regulation functions in the
standard PLC languages: Ladder Diagram (LAD) and function block diagram (FBD).
To create a new project, first the desired programming language must be selected. Either
ladder programming (LAD) or function block programming (FBD).
LAD=LadderDiagram=(LD)
FBD = Function Block Diagram language
LAD (LADDER)
FBD
Figure 1.10 LAD- and FBD-Button
Note:
A ladder diagram (LAD) is not in a function block diagram (FBD), or convertible and vice
versa!
11
2. The Ladder diagram (LAD) (in the Software called „LADDER“)
The corresponding button is clicked to reach the LAD Editor.
LADDER
LAD
Picture 2.1 Start-Menu of the LRXSW for opening LAD
The next step is to select the right MicroPLC. This is necessary in order to assign the right
program of the controller. For this purpose, the "NEW" button is clicked.
Picture 2.2 Start-Button
12
It appears in the device
selection window:
Picture 2.3 device Selection
The selection is based on the device type identifier:
Note:
This choice is also possible later on in the "Operation" -> "Module System Set"
Is the correct device selected via the pull-down button
the LAD Editor opens.
will be confirmed with OK
and
The Ladder Editor is divided into the following areas:
circuit diagram window
Operations
Assignment
list of contacts
and coils
Selection of contacts and coil
13
Information on the circuit diagram
In order to interpret correctly the symbols you place the mouse on the icon, and after a
moment the icon's function appears. The symbol for the outputs Q/Y and the markers M/N
again shows the contact and once the coils function.
Cursor keys (Z) on the MicroPLC
digital
inputs (I)
External inputs (X)
(extension)
Picture 2.5 Contact- and coil function
In the left window of the editor, the contacts and coils used are displayed.
Clicking the button opens the complete selection table.
Picture 2.6 Occupancy list
Note:
The individual short names (Y, M, T, C, R, G, H, ..) are explained in the relevant exercises.
14
2.1
Circuit diagram window
The ladder program is created in the circuit diagram window. It can be constructed of a
maximum of 300 rungs with a maximum of three contacts and one coil. If you need more
than 3 contacts in a rung you need a temporary result memory, a marker M or N.
1
2
5
6
9
etc.
3
4
7
8
Indication of the remaining open spots
Picture 2.7 The Schematic window
2.2
Creating a circuit diagram
Use the mouse pointer to select the contact icon. As an example, we select the input.
When the icon is left appears as a crayon. Using the mouse, now the contact to the right
position is out in the rung.
This is the "pen" and as long as provided with a prohibitory sign, as long as no contact
inserted, the field is reached. Only when the prohibition sign is gone, the contact can be set.
If the position is reached, the contact with the left mouse button "placed". It opens directly the
selection window "Edit contact" through which you enter the parameter.
Picture 2.8
describe contact
15
This window will also determine whether the contact is normally open or normally closed.
A subsequent correction is possible in this menu. With OK the configured contact in the
ladder diagram is visible.
Note:
Unless the right mouse button or the ESC key is pressed, the "pen" is retained and it may be
the next position to be selected.
In the toolbar, there are a lot of contacts and coils of different functions. In this book, some
are handled. But experience shows that many functions even tell if you have worked through
the book.
Picture 2.9 Toolbar
Note:
In the circuit diagram the name of contacts appears different:
NO (normally open)
NC (normally closed)
Picture 2.10 N.O.-contact
Picure 2.11 N.C.-contact
16
2.3
Series circuit
As a first example to three NO contacts switch the output Q01 in series:
Shows the occupied
contacts and coils with
a star
Picture 2.12 First line
If you want to associate less than 3 contacts in series, one
needs an "AND-Line". This function is as an icon button in the bottom toolbar:
Pictue 2.13 AND-Line
AND-Line
Note:
This connection is used instead of a contact!
2.4
Parallel circuit
For this example, we use the previous example of the series circuit and add this with two
parallel contacts I04 and I05. For this purpose, the software in the toolbar “OR-Line” button
for the parallel branch:
Picture 2.14 OR-Line
OR-Line
Example of a parallel circuit:
Picture 2.15 parallel circuit
17
2.5
Digital outputs Q/Y and markers M/N
The digital outputs and markers of MicroPLC can be set in different functions. As standard
the selected output or marker is used as a dynamic coil. This means that the output or
marker behaves as a contactor.
Picture 2.16 discribe coils
Further functions are:
Set-function
Reset-function
P = puls-function
These different opportunities are illustrated in the circuit diagram as follows:
Dyn. coil: -[ =
Set-coil
=
Reset-coil
=
Puls-coil
=
Pictur 2.17 coils
Note:
The function of the output can be changed at any time by double clicking on the
corresponding coil function.
18
2.6
Boolean algebra as a basis
The primary task of MicroPLC LRD is the linking of several NO and NC contacts after a
certain logic. This logic corresponds to a series (AND circuit) or a parallel (OR circuit) in a
wired contactor or relay control. The link can be specified in the LRD either
Ladder Diagram
function block diagram
= LAD or
= FBD.
This plan is stored in non-volatile semiconductor memory of the LRD.
It is important to note that the MicroPLC cannot detect whether an incoming signal from the
outside of a make or break comes. The LRD "remembers" only if the 24 VDC voltage is
applied to the inputs or not.
In the circuit diagram or logic diagram, the logic state of the inputs is always queried and not
the function of the actuator.
19
2.6.1 Logical combinations in the LAD Editor
2.6.1.1 AND-operation
The AND-operation corresponds to the series circuit in a conventional wired contactor control
that means the output is switched on when all switches are closed. The following example
shows a better understanding of how an AND-operation takes place in old fashion wired
contactor technology and how the implementation of the LRD12.
Example: Logical AND-operation with three switches:
Realization in wired contactor circuit
Realization with the LRXSW:
S1
S1
S2
S3
S2
I1
S3
I2
I3
LRD12
ZelioLogic2
Q1
Relay 1
H1
H1
Picture2.19 Wiring to the PLC
Picture 2.18 AND-operation
The output signal (H1), an AND-operation is then logic "1" when all the input signals (S. ..)
have the state "1". The "1" stands for an actuated normally open or a normally closed contact
is not actuated.
True list:
S1 S2 S3
H1
0
1
0
1
0
1
0
1
0
0
0
0
0
0
0
1
0
0
1
1
0
0
1
1
Logic algebra:
FBS:
0
0
0
0
1
1
1
1
S1
S2
AND
S3
Presentation in the LRXSLAD:
LAD
Picture 2.20 AND-operation in LAD
20
H1 = S1 & S2 & S3
H1
2.6.1.2 OR-operation
The OR-operation corresponds to the parallel circuit in a conventional wired relay control,
that is, the output is then turned on when at least one of the switches is closed.
The following example shows a better understanding of how an OR operation in old
fashioned wired contactor technology and how the implementation of the LRD 12 takes
place.
Example: logic OR-operation with three switches
Realization in wired contactor circuit
S1
S2
Realization with the LRXSW:
S3
S1
S2
I1
S3
I2
I3
LRD 12
Q1
Relay1
H1
H1
Picture 2.21 OR-operation
Picture2.22 Wiring to the PLC
The output signal (H1), an OR operation is then logic "1" if at least one or more input signals
(S. ..) have the state "1". The "1" stands for an actuated normally open contact or a nonactuated normally closed contact.
True list:
S1 S2 S3
0 0 0
1 0 0
0 1 0
1 1 0
0 0 1
1 0 1
0 1 1
1 1 1
Logic algebra:
FBS:
H1
0
1
1
1
1
1
1
1
S1
S2
OR
H1
S3
Presentation in the LRXSLAD:
LAD
Picture 2.23 OR-operation in LAD
21
H1 = S1 V S2 V S3
2.6.1.3 The AND- before OR operation
The three switches to be logically combined in AND and OR.
The input of this logic is based on the basic rule of Boolean algebra:
Point are performed before addition and subtraction
In the implementation in the wiring logic, this means:
Series circuit is going on parallel circuit
The following example shows the implementation a combined AND-OR circuit according to
the rule above mentioned:
Realization in wired contactor circuit
Realization with the LRXSW:
S1
S1
S2
S3
S3
I1
I2
I3
LRD 12
S2
Q1
Relay1
H1
H1
Picture 2.24 AND before OR operation
True list:
S1
0
1
0
1
0
1
0
1
S2
0
0
1
1
0
0
1
1
S3
0
0
0
0
1
1
1
1
Picture2.25 Wiring to the PLC
Logic algebra:
FBS:
H1
0
0
0
1
1
1
1
1
H1 = S1 & S2 V S3
S1
S2
AND
OR
S3
LAD
Picture 2.26 AND before OR operation in LRXSLAD
22
H1
2.6.1.4 The OR before AND operation
Four switches will be connected in logic OR and logic AND:
The input of this logic is also called conjunctive form. Since the Boolean rule applies here, it
must be used with braces. Thus, it specifies that the OR operation is processed first. The
representation in the application program corresponds to the international standard IEC
61131.
The following example shows the implementation a combined AND-OR circuit following the
rule above mentioned:
Realization in wired contactor circuit
Realization with the LRXSW
S1
S1
S2
S3
S4
S2
I1
S3
I2
I3
I4
LRD 12
S4
Q1
H1
Relay1
H1
Picture2.27 OR before AND operation
True list:
S1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
S2
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
S3
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
Picture2.28 Wiring to the PLC
Logic algebra:
FBS:
S4
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
H1
0
0
0
0
0
1
1
1
0
1
1
1
0
1
1
1
H1 = (S1 V S2) & ( S3 V S4)
S1
OR
S2
AND
S3
OR
S4
23
H1
Presentation in the LRXSLAD:
LAD
Picture2.29 OR before AND operation in LAD
Exercise: Basic circuits with the LAD Editor
LAD 1a / LAD 1b / LAD 1c
I1
I2
LAD 1b
Q1
L AD 1a
I3
I1
I2
I0A
I1
I4
I5
I6
Q1
I2
I3
I3
Q2
LAD 1 c
Q1
Q2
I4
I6
I4
I5
I9
I5
I6
I9
I0A
Q3
Q4
I9
I0A
LR D12
Picture 2.30
Exercise card LAD1a
LR D12
LR D 12
Picture 2.31
Exercise card LAD1b
24
Picture 2.32
Exercise card LAD1a
2.6.1.5
Latching
In control engineering, the function of latching is often use, especially when using buttons will
execute a stored function. A typical task is the turning on and off of a motor. The ON button
is always a normally open and the OFF button always normally closed. Why the OFF button
is normally closed, has something to do with the wire breakage. The VDE regulations state
that in the event of a wire break in the relevant section a motor must be switched off
immediately and must not be turned on.
To realize a latching in the LRD12 and LRD20 the MicroPLC offers two variants.
1. The dynamic control of the output:
If the result of logic operation (RLO) is on , the output is on, too.
If the RLO is low , the output is low, too.
Picture 2.33 dyn. latching in LAD
2. The static control of the output
Latching function with SET and RESET commands.
Both commands work with the rising edge.
Picture 2.34 static latching in LAD
25
Exercise: Latching
With these exercise cards the topic of wire breakage is practiced. For all programmable
logic controllers (PLCs) you must make sure which switch or push button is installed on
the machine or plant. Is it a N.O. or N.C. contact? This is important because according to
VDE 0113 turn off must be by opening a circuit. By using an N.C. to the input terminal of
a PLC, this always has power at the input terminal in the non-actuated state. If you were
to now integrate the input by an N.C. in the schematic, so you return the signal of the
external switch. This has the consequence that e.g. a motor off by opening the circuit at
the input of the PLC. This can be life-threatening. Thus, we conclude that one must
always think twice when you include one outside the PLC wired N.C. in the program as
N.O. or N.C. to be failsafe.
Exercise LAD2: Latching with dynamic triggering of Q2
(Like the classic relay and contactor control)
Sel bsthal teschal tung
seal-i n circui t
LAD 2
Start
Stop
Bimetall
I4
I5
Q2
I3
Q2
Bei der Programmerstellung ist auf
die Drahtbruchsicherheit zu achten!
In case of programming pay attention
to the fail-save c ircuit
Picture 2.35 Exercise card LAD2
LR D 12
Exercise LAD3: Latching with static triggering of Q2
(Like classical electronic controls via flip-flops)
Sel bsthal te schaltung mit SET un d RESET
Seal-in circuit wi th SET and R ESET
L AD 3
Start
S
I3
Q2
R
I5
I6
Bei der Programmerstellung ist auf
die Drahtbruchsicherheit zu achten!
In case of programming pay attention
to the fail-save c ircuit
Picture 2.36 Exercise card LAD3
LRD 12
26
2.6.1.6 Priority processing - dominant
Another important overview is the priority of functions. The program processing is always
from top to bottom, is in the ascending line numbering.
The example shows how important it is in which line the output or marker are standing.
This is also important with respect to the priority in the setting and reset command.
1a
If
I1
and
I2
are
pressed
simultaneously, the RESET command
has priority.
1a
1b
I3 and I4 are pressed simultaneously,
the SET command has priority.
1b
1c
If a coil is several times assigned,it is
also true that the ascending line
numbers, the last assign which affects
the coil to the outside. Internally, the
coil of the output or marker "1" or "0"
as long as no change is made in the
following lines.
1c
Picture 2.37 Priority processing in LAD
27
2.7 Simulation
After the last link is ready, this is simulated with the help of LRXSW, i.e. tested without
control (off-line). For this we change into the SIMULATION MODE:
Picture 2.38 Tools in LAD
Depending on the settings more windows are opened simultaneously. Since we are
interested only in the inputs, the other windows can be closed. This takes place using the
"View"
“
By clicking on the fields, tools can show or
hide!
Picture 2.39 View menue
By clicking the button icons in the "Input Status Tool", the
corresponding switch in the LAD is displayed in green. If the
rung is virtually closed, that is, from left to right is a continuous
green line, then the output is also available in green.
(The connecting lines "OR-Line" and "AND-Line" always appear in
green)
Picture 2.40 OR-Line and AND-Line
28
2.7.1 Simulation on the virtual controller
In addition to simulating the circuit diagram, the controller also provides a pictorial
representation of LRD12 with the connected switches and lamps. You can reach this
simulation by clicking the "keypad"
Run
Picture 2.41 keypad button
By clicking the "Run" button, the program can now be tested on the simulator.
Click switch
Current paths, the bold
appear to be "flown
through" virtual power!
Outputs
Picture 2.42 Keypad-Simulator
With the mouse, you can also use the cursor buttons to operate virtually and thus retrieve the
LRD12 the menu and use.
Note:
In this virtual control simulator parameters can be changed, but the function of a function
block cannot.
29
2.8
The Online Test
2.8.1 Coupling
Before the transfer of a program can be done in the controller, some settings must be
checked, or set. These settings, bring the selected control to meet the actual control system.
If this is not the case, the LRXSW recognizes and cannot connect.
The exact type of control can be found on the left
side wall!
example: LRD12TD024
The protective cover should be pulled out and
the plug inserted carefully. The cable goes from
the left.
Picture 2.43 Cuppling to the PC
The USB programming cable is plugged into one of the USB ports of the PC.
If the connection is made, and power is connected, then the coupling of the software can be
made:
1. Click "Operation"
2. Click "Link COM Port"
3. Select the interface "COM port"
Picture 2.45 Select Link Com Port…
4. Click Connect "link"!
Picture 2.44 Link Com Port…
If the coupling was successful, this is indicated by a message
on the screen.
Picture 2.46 Connect successfully
30
2.8.2 Program transfer
The next step is to transfer the program into the controller. For this the LAD editor provides
two buttons. One to write the program into the control "write" and another to read the
program again from the controller back to the PC "read".
Read from the LRD…
write into the LRD…
Picture 2.47 Read and Write Button
After a safety prompt with the hint that you could
possibly overwrite a program in the control (clear).
Picture 2.48 Message
If you confirm with "Yes", the program is transferred to
the controller. Then you acknowledged with the “OK” for
transfer:
Picture 2.49 Transfer o.k.
With the "Run" button the program starts in the
controllerand with the "Stop" button, the program
can be stopped anytime from the PC.
Picture 2.50 Run and Stop Button
If you click "Run", the system asks whether
the program should be read back from the
controller. This makes sense if you just want
to see the online status display.
Picture 2.51 Message
31
2.9
Time relay (timer) T
The MicroSPS LRD… provides 30 timing relays with different possible functions. The button
"T" is chosen from the lower function selection panel to open the configuration window for the
functions and their settings.
Picture 2.52 Tools
2.9.1 Configuration window of time relay (timer):
Selection of 30 possible timer addresses:
01…09, 0A…0F, 10…19,1A…1F
Function of the output coil of the timer (Output
Type):
–[ = Dynamic coil (in the example selected)
P = Pulse output
Picture 2.53 Timer select
Function of the timer depending on the output coil
(Output Type):
Mode 0 – 6 for : –[
Mode 7 for : P
Mode 0: internal coil (like a marker)
Mode 1: On-delay timer
Flow diagram
Picture 2.54 Timer mode1
Mode 2: ON-delay timer with reset input.
If the enable is off, the timer stops. Only
if the Enable is "ON" the time is running
on again.
Picture 2.55 Timer mode2
32
Mode 3: OFF-delay timer.If the rising edge of
Enable (0 -> 1), the output is "ON". Time
is running only when the Enable flank
falls (1 -> 0). If Enable is turned on
again during the running time, the actual
value is set to "0". The timer can be
restarted.
Picture 2.56 Timer mode3
Mode 4: OFF-delay timer. When a falling edge of
Enable (1 -> 0), the output is "ON" and
the time is running out. If Enable is
turned on again during the running time,
the Actual value of the timer is reset to
"0". The timer can be restarted.
Picture 2.57 Timer mode4
Mode 5: Synchronous flasher (1:1)
(ON-time = OFF-time)
The output of the timer flashes
while the Enable "ON".
Picture 2.58 Timer mode5
D Mode 6: Synchronous flasher (1:1)
M
(ON-time = OFF-time) The output of the
Ö
timer flashes once to Enable an edge
G
change from 0 - done> 1. The output
D
flash until an edge change from 0 -> 1
F
at the Reset input is done.
Picture 2.59 Timer mode6
Mode 7: Asynchronous flasher (1: n) (ON-time is
not equal the OFF-time) The output of
the timer flashes while the Enable
"ON".
Picture 2.60 Timer mode7
33
2.9.2 Setpoint input at time relay
The input for the time functions are also included in the menu window of the timer
corresponding to the mode that is set.
By default, the time base is set to 10ms. That the
smallest default value for the timer is 10 ms.
The time
base
from … to
0,01 … 999,9 s
0,1 … 9999 s
1 … 9999 s
1 … 9999 min
„PresetValue“
Setpoint input with consideration of the time
base (SEConds or MINuntes)
Picture 2.61 Timer parameter
"Preset Type" is used when the target value from
another block comes. So, for example, is "A" for
analog input or "C" for a counter output. If
setpoint "Preset Value" is specified, the Preset
Type = "N" (Not)
For the asynchronous flasher (Mode 7) Two
setpoints are required. Accordingly, two setting
ranges (T01 and T02) are provided.
Picture 2.62 Timer mode7
34
2.9.1 Presentation of the timer in the circuit diagram LAD
If the timer is configured, it is shown in the circuit diagram as follows:
Mode (0…7)
Current value
Setpoint
Picture 2.63 Timer in LAD
In the run status of the timer is displayed as follows:
Current value
Picture 2.64 Timer in Run
2.9.4 Display of the timer on the display of LRD…
In addition to the status display on the screen, it is particularly convenient when for example
you can read the value of the timer and the controller. This is often a great help for setup or
troubleshooting. For this purpose, proceed as follows:
If the controller is in Run mode, it comes with pressing the button
in the following menu:
Picture 2.66 LRD… Menue
The cursor key
leads to the circuit diagram. There you go using the arrow keys on the
corresponding block and confirm
. Use the
key to get back into the schematic.
Picture 2.67 LRD-Display
Timer in Run
35
2.9.5 Change the setpoint on display?
Many times it happens in the everyday life of a machine or system that a value needs to be
adjusted, but there is no PC for set-point modification.
For this the controller offers, thanks to its built-in display among other things, the possibility to
change settings.
The change is ALWAYS in
STOP mode.
Picture 2.67 LRD-Display:
in Stop mode
With the keys is now the timer component T1 called:
1. Press the
key.
2. Go with the Cursor-key
up
and
confirm.
3. Use the cursor button
to repeatedly tap to the left until the position is
reached at which point the value is to be changed.
4. Pressing the
button, the position is confirmed and the cursor line
below the number flashes.
5. Use the cursor keys
and
now the new value can be set.
6. If the value is correct, you confirmed with
36
and leave the menu with
Exercises: Time Relay T
LAD4:
With the exercise card " Time relay T1"
first we test all the modes of a timer!
Zeitrelais T1
Time relay T1
LA D4
I2 Start
T01
Enable
Q2
Output
I4
MOD E
Reset
LR D 12
Picture 2.68 Exercise card LAD4
LAD 4a:
Based on the adjacent exercise card is a reflector light
barrier (I02) four monitoring lights (Q1 ... Q4) switch for 10s.
To switch on it is enough if, for example, a person shortly
interrupts the light barrier. With each new interruption of the
photocell, the timer is restarted. Which mode is useful here?
?
LAD 4b:
The interrupt pulse of the light barrier is to be fixed at 0.2 s.
Picture 2.69 Exercise card LAD4a+b
LAD 5a + b
Lic ht
la mp
lu z
Q1
Q2
Lüfter
fan
ven ti lad or
LAD 5 a:
A toilet light and fan control is to be implemented using the
LRD…. If someone enters the bathroom and switched on
the light, after 4s the fan runs on as well. Only when the
toilet is left and the light is switched off, the fan runs for 8s
and then switches off.
LAD 5b:
In addition to LAD 5a, the fan should now run after 20 s,
when the toilet is used for longer than 20 seconds and the
light is longer than 24s on.
S5
Schalter
swi tch
in te rruptor
Toi letten -Li cht-Lüfte rsteu erun g
Toi let -Li ght-an d-Fan Co ntrol
Co ntrola dor de l a lu z y el ven ti lad or de un ba ~
no
LR D 12
Picture 2.70 Exercise card LAD5a+b
37
I1
Le uchtfeue r / Navi gatio nal l igh t
Q1
I2
Westerheversand
I3
Q2
Büsum
Q3
Helgoland
LAD 6 - Lighthouse:
On the North Sea coast are navigation beacons for
safe orientation. These can be seen from a distance
and in the dark they have different identifiers to see
which beacon is which. They are the broken fire (Oc),
the common-mode fire (iso) and the flashing light (LFI).
These three identifiers will now be realized with the
help of exercise LAD6 card.
1) Lighthouse from Westerheversand - Oc(3) 15:
01 234 5 6
LR D 12
Picture 2.71 Exercise card LAD6
15s
3 dark phases of 1s and the two pauses of 1 s. Then
is permanent light. The repeat is done every 15s.
2) Lighthouse from Büsum- Iso 6s:
0
3
6s
On 3s and off 3s
3) Lighthouse from Helgoland- LFI 5s:
0
5s
all 5s a flash fire <1s (600ms)
Ampel / Traffic light
LAD 7
LAD7:
In metropolitan areas, side road access to highways is
controlled in heavy traffic with a traffic light.
The traffic light shows RED when the main switch I01 is
turned on. An induction loop in the road surface before
the traffic light detects an incoming vehicle. With 1s
delay starts the traffic light cycle, which also takes 1
sec each for the individual phases. At the end of the
traffic light cycle the lights are back on RED. If the
induction loop is connected constantly, so the traffic
lights cycle runs through the 1 sec intervals.
LR D12
Picture 2.72 Exercise card LAD7
38
2.10
Differential Instruction D
The "positive" pulse is for one program cycle "ON" if the series contact switches from
OFF -> ON.
Picture 2.73 D puls when ON
The same function but with the opposite sign is the inverse of the "D" contact.
Picture 2.74 D-puls when OFF
39
2.10
Counter C
Like the timer, the counter is also a function block that needs to be configured only. The
MicroPLC offers 30 counter blocks, each with 8 different modes.
Picture 2.75 counter parameter
Mode 0: internal coil (like a marker)
Mode 1: up-down counter without overflow. If the setpoint
= actual counting up is blocked. The counting is
stopped if the actual value = 0. The actual value
is non-retentive. It loses its value when you turn
off the controller.
Setpoint input (0 ... 999999)
Variables specification (for example: the result of
arithmetic)
Note:
In LAD circuit diagram ONLY be linked the counting coil
and the switching output of the counter. The specification
of the counting direction (Direction set) and the reset Input
of the counter value can be selected in the configuration
window and displayed as in the example:
"Low" = "0" = no specification
The representation in the LAD editor provides the following information:
Mode
Direction
Counting coil
Actual value
Setpoint
Switching output of the counter
Reset Input
Picture 2.76 counter in LAD
If you want to reset the counter and / or changing
direction, then the menu offers various options:
Low = not specified
for example: Reset Input
I
= Input base unit
X
= Input expansion unit
Z
= cursor keys (arrows) as inputs etc
40
Picture 2.77 Reset Input of the counter
Mode 2: up-down counter with overflow.
If the setpoint = actual value of the count input is
not locked. The counter continues to count. The
actual value is non-retentive. It loses its value
when you turn off the controller.
Example, in the LAD representation:
Picture 2.78 counter mode2
Picture 2.79 counter in stop
Note to "reset input" and "Direction Set" in Mode 2:
•
•
"Reset input" has two functions. When pressed while counting the reset, the current
value of the counter is set to "0". When pressed while counting down the reset, then
the setpoint "Preset Value" is set!
If the setpoint is reached when counting, the output switches the counter to "ON".
Now, if the direction is switched, the output switches to "OFF" and again until the
actual value = "0", the output is switched to "ON". Now, if the direction switched
again, the output switches back to "OFF" until the setpoint is reached again.
Mode 3: Like Mode 1, but the actual value is retentive. It stores its actual value when
you turn off the controller.
Mode 4: Like Mode 2, but the actual value is retentive. It stores its actual value when
you turn off the controller.
Mode 5: Like Mode 2, but with the reset value is always set to "0", irrespective of the
direction.
Mode 6: Like Mode 5 but retentive.
Mode 7: High-speed counter, which is used either as pure up counter on the highspeed counter inputs I1 or I2.
Mode 8: 1 KHz-speed counter, which is used either as pure up counter on the highspeed counter inputs I1 or I2.
Picture 2.80 counter in Run mode
41
Exercises: Counter C
I1 Puls
I2
I3
Direction
Zä hler C01
c ounter C01
LAD8
Q1
LAD8
Should be tested before the following exercises are done with
the exercises card "counter C01", all modes.
Reset
Mode
Preset Value
Picture 2.81 Exercise card LAD8
I1
Sollwertvorgabe mit Vor-Rückwärtszähler
setpoint via up-down counter
LAD8a/8b / FBD7a /7b
Q1
START
Preset Value
LAD8a:
Using an up-down counter of the setpoint value for a timer
from 0 to 50 sec ... be adjustable. As the setting buttons Z
keys are used. With Z01 is forward (UP), with Z03
backward (DOWN) counted.
LAD8b: Extension
The setpoint and the actual value of the timer should be
displayed on the display of the LRD.
Timer 2
Counter
Setpoint
UP
DOWN
Actual value
Min=0
Max=50
LR D20
Picture 2.82 Exercise card LAD8a+b
fa hrt
I1 Ein
en tra nce
rt
I2 Ausfah
exi t
Par khaus / Park ing gar age
LAD 9
FREI / FREE
BELEGT / BUSY
I3
Geschlossen /closed
LAD9:
A car park entrance is controlled by display. A total of 20
parking spaces available. If all are occupied, the display
shows "Busy". Otherwise, the display is set to "FREE".
The caretaker also has the option, regardless of the
allocation to close the driveway with a roller door. Is the
roller door down, the display shows "CLOSED" on.
Contact entrance
Contact exit
Contact door below
Display “FREE“
Display „BUSY“
Display „CLOSED“
LR D12
Picture 2.83 Exercise card LAD9a+b
42
: I01
: I02
: I03
: Q01
: Q02
: Q03
2.12
Shift register S01
The function block "shift register" is a bit shift register and is available once. It can max. be 8
steps high.
Number of shift increments
„Select 1-8“
„Pulse Coil“
„Start Coil“
Picture 2.84 Shift register in LAD
The start-coil defines the first step in the shift register.
It can be an output (Q, Y) or relays (M, N).
If you have chosen a variable, all outputs or markers
that are defined with "Select 1-8", assigned.
The clock-coil "Pulse Coil" defines the shift clock. It
can be any variable in NO or NC function.
Picture 2.85 Parameter of S01
„Start Coil“
In this example, the outputs
Q1-Q4 are occupied by the
shift register.
Q01
Q02
Q03
Q04
The shift register operates as a shift register ring. This means in this example that the fourth
time clock with the output Q01 I02 back "ON".
43
Exercises: shift register S01
I1
Start
Schiebere giste r / Shiftre giste r
LA D 10
LAD10:
We have a shift register with eight steps. The training card
shows all necessary variables. The shift register shifts first
from M01 to M08. The markers then drive the outputs Q1 ...
Q8. Since the LRD12 has only 4 physical outputs, the
remaining 4 outputs are virtually visible on the display.
The shift clock (T1) of 1s becomes active when I1 is
actuated. After 8 steps of shift clock starts again while I1 is
switched off.
Q1
S01
Start
M01
Coil
T1
Q2
M02
Q3
Pulse
coil
M03
M04
M05
M06
M07
M08
LR D20
Q4
Q5
I1
Start
Schiebere gister / Shiftregister
LAD 1 0
Q6
Q7T1
Q8
Picture 2.86a
Exercise card LAD10
for LRC20
Q1
S01
Start
M01
Coil
M02
Pulse
coil
Q2
M03
M04
Display
M05
Q3
M06
M07
M08
Q4
LR D12
Picture 2.86b
Exercise card LAD10
for LRC12
LAD11:
In this exercise, the shift register is to be extended
from LAD10 as traffic light control. Once I1 is turned
on runs the traffic lights cycle from according to the
diagram.
I1
Start
S01
A mpel m it Schie be register
Tr affic light with shiftre giste r
LAD 11
1
2 3 4 5 6 7 sec.
LR D12
Picture 2.87 Exercise card LAD11
44
2.13
Analog comparator G
The 24VDC base unit LRD12 provides two analog inputs A1 and A2. The analog value from
0 to 10V is applied to an analog to digital converter on the inputs, and converted into a binary
number. The converted value can be compared via the analog-comparator block G with
different values. The analog comparator values offers 8 modes
Mode 0: is always an internal coil.
Mode 1: (Ay-Ref.) <= Ax <= (Ay+Ref.)
Ax and Ay can be assigned differently.
With the direct assignment to the potentiometer of the
MiniTrainer we can easily try out the formula.
Ax = e.g.: A01
Ay = e.g.: A02
Example:
If the reference value is set to 03:00 and the
potentiometer A2 to 6V, the output of the analog
comparator switched on by turning the potentiometer A1
of at 3V and at 9V.
Picture 2.88 Parameter of Ax
Mode 2: (Ax <= Ay)
The output of the block "G" is "1", if the analog value of
A1 is less than or equal to the value of A2.
Ax = Adjustable example: A1
Ay = A2
The other functions:
Mode 3: (Ax> = Ay) Ax greater than, equal Ay
Mode 4: (Ax <= Ref.) Ax less than, equal a fixed value
Picture 2.89 Parameter of Ay
Mode 5: (Ax >= Ref.) Ax greater than, equal a fixed
value
Mode 6: (Ax = Ref.) Ax equal a fixed value
Mode 7: (Ax> <Ref.) Ax smaller or larger but not
equal to a fixed value.
45
Exercises: Analog comparator G
Q1
Analogwer teve rgle ic he r
A na log c om pa rator
LA D12
LAD12:
Using the analog comarator G in mode 1, to switch Q1
when the difference between A01 and A02 is <= 3V. For
checking the status display is used to display the LRD...
Mode 1
A1
A2
LR D12
Picture 2.90 Exercise card LAD12
Wass ertank
Wa ter tank
LAD 13 /1 5
Q1
ON/OF F
Q2
50°C
Heizung
heating
Q3
LAD13:
The temperature of a water tank is to be kept at 50 ° C -2
° C. I1 is used as the main switch. The heating is
controlled by Q2. The temperature curve of the sensor
corresponds to the sketch. If the temperature is above 55
° C or below 45 ° C then the alarm rings (Q3).
°C
90
55
50
45
Alarm
A1
LR D12
0
? ? ?
10V
Picture 2.91
Exercise card LAD13/15
Note:
If you use LRD20 , the outputs are differently:
LRD12
LRD20
Q1
=
Q1
Q2
=
Q3
Q3
=
Q5
46
2.14 Real Time Clock R
The clock module in small controllers, such as the MicroPLC represents a fixed function in
many applications. It can be used to realize time-, and date-dependent switching functions.
The Real Time Clock (RTC) provides in MicroPLC LRD… four different modes:
Mode 1: weekly timer
The daily set on and off time applies for the set period every
day. The entry is in hours and minutes (00:00 to 23:59)
MO
TU
WE
TH
FR
SA
SU
Picture 2.93 RTC mode 1
Mode 2: weekly timer
The selected on time may be at a different day than the off
time. The set period applies max. for one week.
The input is as in Mode 1
MO
TU
WE
TH
FR
SA
SU
Picture 2.92 RTC menu
Picture 2.94 RTC mode 2
Mode 3: Year time switch
The set switch-on is on a day and is always at 00:00 clock. The off time is usually on a
different day at 23:59 clock. The period may extend over several years.
ON
OFF
Picture 2.95 RTC – Mode 3
47
Mode 4: pulse clock
On Thursday (TU) at 16:25 clock for a period
of 14 sec, the output of the real-time clock is switched
"ON".
Picture 2.96 RTC – Mode 4
Exercise: Real Time Clock R
Real Time Clo ck
RTC
LAD14
Q1
LAD14:
The outdoor advertising (Q1) of a shoe shop will be
switch on and off automatically over the real time clock.
The times are set as follows:
Mon-Fri at 7:00 A.M. ON and at 6:30 P.M. OFF
Thu additionally at 7:00 P.M. ON and at
10:30 P.M. OFF
Day
Monday
Tuesday
Wednesday
Thursday
Friday
ON
OFF
7:00 a.m. 6:30 p.m.
7:00 a,m, 6:30 p.m.
7:00 a.m. 6:30 p.m.
7:00 a. m. 6:30 p.m.
8:00 p. m 10:30 p.m.
7:00 a. m. 6:30 p.m.
LR D20
Picture 2.97 Exercise card 14
48
2.15
Arithmetic blocks AS (ADD / SUB) and MD (MUL / DIV)
If you want to compare different values or limit values in a particular area, then you have to
rely on the arithmetic. The four basic arithmetic operations are divided into two functional
blocks. First, the addition (ADD) and subtraction (SUB) and on the other hand, the
multiplication (MUL) and the division (DIV).
Picture 2.98 Tools
ADD / SUB
MUL / DIV
Example:
The example shows a timing of a timing relay that between 10 and 50 seconds over the
potentiometer A1 should be adjustable:
If we assume that the analog input A01 from 0 ... 1023 has been set, then the result for the
delta of 40s (10 ... 50s), the following formula (MD01):
Result
=
A1 x 10
= V1 * V2 / V3
256
Analog input A1 multiplied (MUL) with 10, divided (DIV) by 256
V1
*
V2
/
V3
This requires the MD01 module with the entries for V1, V2 and V3:
Picture 2.99 MD function
With the next formula (AS01) is added to the offset of 10s the result of MD01 added:
Picture 2.100 AS function
49
The result is now as required between 10 .... 50. If we now have the time base of the timer
set to "sec", then the task is complete and can be tested with the simulator:
Picture 2.101 Simulation of arithmetic
Exercise arithmetic AS
Wass ertank
Wa ter tank
LAD 13 /1 5
Q1
ON/OFF
Q2
50°C
Heizung
heating
LAD15:
In addition to LAD13 the temperature is shown on the
online display on the PC's screen.
In the next step, if the chapter "Text display" has been
processed, the temperature should be displayed on the
display of the LRD (LAD16).
Q3
Alarm
A1
Picture 2.103 Online status display
LR D12
Picture 2.102
Exercise card LAD13/15
°C
90
50
0
? ? ?
10V
Picture 2.104 What is the voltage at which
Temperature at the analog input?
50
2.16
Data register DR
In contrast to markers (M and N) in which one can store only one bit (0/1), max offer. 225
data register values also with the option to save. These data registers are to be
parameterized in other blocks.
Example:
The result of an arithmetic calculation is to be displayed on the screen of the controller.
1 Step: The result is stored in the data register DR01.
2. Step: In the HMI / Text editor of this DR01 is included
in the display
Picture 2.105 DR menu
Picture 2.106 Content of DR to the text display
Exercise: Data register DR
fa hrt
I1 Ein
en tra nce
rt
I2 Ausfah
exi t
Par khaus / Park ing gar age
LAD 9
LAD9a:
FREI / FREE
BELEGT / BUSY
I3
Geschlossen /closed
Is in addition to the display of the LAD9 now LRD...
take over the display and the remaining free parking
spaces is shown
FREE
LR D12
Picture 2.107 Exercise card LAD9
Note:
Display of remaining free
parking
Exercise 2.108
Text on the Display
of the LRD…
51
Picture 2.109 Online display
2.17
Multiplexer MX
Each of the 30 Multiplexer blocks offers the possibility to assign up to 4 variables to a
setpoint input. The query of the variables is binary, using two bits.
Example:
A timer T01 to run at 4 different times depending on the application. The four variables
(setpoints) are to be pre-selected by the two inputs I1 and I2.
Prefix:
I1
I2
Setpoint
0
1
0
1
0
0
1
1
1
10
100
200
I
Picture 2.110 Multiplexer Menu
Depending on the combination of the switches I1 and I2 corresponding to the setpoint, it is
assigned to the timer. The timer module T01 at the setpoint input, the reference to the
multiplexer module is entered MX01.
Bild 2.111 Multiplexer in LAD
52
2.18
Text display H
The MicroPLC offers the possibility of process-dependent texts with and without displaying
variables together with the built-in display. For this the text module H is called in the program.
Block-No.: 1 up 1F =
30 Text displays
Picture 2.112 Text block
Mode 1: MicroPLC with display
Mode 2: MicroPLC without display, that means for an external
display
To enter text you will see in the menu bar of the software, the button "HMI / text" to be
"clicked".
Picture 2.113 To enter Text
It opens the following menu:
Note:
The display of the LRD ... offers 4 lines
with 16 characters each.
Picture 2.114 Text input menu
53
2
1
4
3
Picture 2.115 Text input
1
If the display is activated (hook set), the user can view the SEL button to select the
text. Use the ESC key, the text is cut off again.
2
Here, the variable can be with their unit select (Timer / counter / clock and analog
comparator).
3
Here, the coil state of I, M, X and Z are shown. If you select the representation with the
operand, then it is displayed as follows:
e.g.: I01(unit)
If no operands are selected e.g. "I01", only the state is shown:
4
„Analog Display Set“ :
Here, another menu opens in
which the amplification factor
(gain) (1 ~ 999) and / or the
offset (-50 ~ +50) is set.
Picture 2.116 a+b Variable input
54
The example will now show how the analog input A1, with a gain of 100, and an offset of 50
in the display is visible.
With the input I1, the variable to be displayed on the display of LRD12.
The program is as follows:
Picture 2.117 Text block in LAD
Once the program is created, the HMI / Text window is opened and provided with the
following entries:
1. step
The gain and offset of A1 defined:
(e.g. Gain = 100 and Offset = 50)
2. step
a) Where the value should appear in the "HMI
/ Text" menu, enter text and click the cursor to
the position.
b) Then click on the selection window of the
analog inputs and "A1" to select.
Picture 2.118 Analog Set - menu
a)
b)
3. step
Possibly one more text to add.
4. step
Transfer and storage in the control
Picture 2.119 Embed variable in the text
Exercise: Text display
LRD 16:
As a supplement to LAD13 and LAD15 the
temperature is shown in addition to the display of
the LRD.
Picture 2.120 Display in the LRD…
55
2.19
Comments for coil and contacts
In practice, it often is not appropriate to use the coil and contacts with the names in the
schematic. An appropriate comment increases the clarity and the reference to the machine
and plant.
Under the menu item "Edit" you will find the "Symbol ..."
If you click on "Symbol ..." you open a selection window in which you can select the desired
coil and contacts and provide comments.
Text input
Picture 2.121 open Text Input
Picture 2.122 Text Input
These then appear on the LAD chart below the contact and the coil.
Picture 2.123 Text representation
56
2.20
Headlines and comments in the Ladder Diagram
In a project it is very important that some program sections are commented. This makes the
start-up and later troubleshooting much easier, thus saving costly downtime of a machine or
system.
For commenting the software offers the button "Note"
Pictures 2.124 Comment Input Button
If you have clicked this button, it will be like a coil or a contact to the location of the circuit
diagram set. Then open the window for entering the text. There are 4 lines of 50 characters
each available to you.
Pictures 2.125 Comment Input Menu
Note:
Each comment is always uses one line in the ladder diagram.
Picture 2.126 Comment representation
57
3.
Function block diagram FBD
If you want to create this project in function block language you have to click the button
"FBD" just after opening the software.
Function block
diagram FBD
Picture 3.1 Start Menu of the LRXSW to FBD
One comes directly into the selection menu for the control. As in the LAD editor, we select
the correct device LRD12TD024
Picture 3.2 Device selection menu
58
Click "OK" to return into the FBD editor. If the operating window is too small, it can be
adjusted either under the "View" menu, "Zoom In" or drag the "Zoom Out" larger or smaller,
or you can use the zoom function button:
Picture 3.3 Zoom function
If the operating windows are
multiplied, that is made possible
by on-click of the button.
Working window
Picture 3.4 Customize the working window
To make all the icons visible click the button
Picture 3.5 All symbols
Like in the LAD editor most of the symbols in the respective chapters are explained.
59
3.1
Creating a function block diagram
With the mouse pointer you select a logic symbol. As an example, we select the input.
When the icon is selected it will appear on the field of work on mouse-pointer following logic
symbol
. When it is directed to the appropriate location, click on the left mouse button
and the proper logic symbol is "stored".
This is now stored with each click until you press the right mouse button or selecting a
different icon. If you want to delete a logic icon again, it is clicked with the right mouse button.
The following menu appears:
Picture 3.6 Delete
Or can be deleted with the "delete" key.
With a double click of the left mouse button on the icon, a menu selection where one
operand number appears. May change (input number) and store an operand text (icon).
Picture 3.7 Parameter Input
60
In addition to the operand text, it is possible to store a general comment and to displace it
with the mouse. To do this click with the right mouse button in the free field of work. The
following window appears:
Picture 3.8 To comment entry
If you click "Insert Comments" first appears next to the mouse pointer a "T". You position it
by clicking the left mouse button, the input window appears:
Picture 3.9 Comment Input
This comment is always displaced by clicking it with the left mouse button. It is marked with
four red corners and can be moved around now.
If you want to delete it again one uses the "Del" key on the PC keyboard. This also applies to
all the logic symbols and connections.
3.1.1 Draw connections
If you have placed at least two logic modules, you can connect them logically. For this, the
link button is clicked and dragged to the field of work.
Now you go with the mouse pointer to the quasi-dependents of the wiring to the module input
or output. Whether you have "hit" the corresponding input or output can be recognized by a
small square. One click and the connection can be drawn.
Picture 3.10 Draw connections
Note:
If you have a straight logic symbol placed you can directly drag the link without having to
click on the link button.
61
3.2
Logic sets in the FBD-Editor
3.2.1 AND operation
The AND operation corresponds to the series circuit in a conventional, wired contactor
control, the output is switched on when all switches are closed.
Example: Logical AND operation with three digital inputs
The output signal (H1), an AND operation is then "1" when all the input signals
(S. ..) have the state "1". The "1" stands for an actuated normally open N.O. or a
normally closed N.C. contact is not actuated.
True list:
S1 S2 S3
H1
0
1
0
1
0
1
0
1
0
0
0
0
0
0
0
1
0
0
1
1
0
0
1
1
Logic algebra:
FBS:
0
0
0
0
1
1
1
1
H1 = S1 & S2 & S3
S1
S2
S3
H1
H1
This "AND" supplies at the output
(H1) for a cycle length a "1". The
block can also be used as
pulsemodule!
Picture 3.11 AND-operation
FBD
Picture 3.12 AND operation in FBD
62
3.2.2 AND NOT-operation (NAND)
The NAND operation corresponds to the series circuit in a conventional-wired contactor
control, the output is turned off when all the switches are closed.
Example: Logical NAND with three digital inputs
The output signal (H1) of a NAND is always "0" if all the input signals (S. ..) have the state
"1". The "1" stands for an actuated normally open or a normally closed contact is not
actuated.
True list:
S1 S2 S3
H1
0
1
0
1
0
1
0
1
1
1
1
1
1
1
1
0
0
0
1
1
0
0
1
1
Logic algebra:
FBS:
0
0
0
0
1
1
1
1
S1
S2
S3
H1 = S1 & S2 & S3
H1
This "NAND" the output only
delivers a "1" if a pulse of the
input "0".
Picture 3.13 NAND operation
FBD
Picture 3.14 NAND operation in FBD
63
3.2.3 OR operation
The OR operation corresponds to the parallel circuit in a conventional wired voltage control,
that is, the output is turned on when at least one of the three switches is closed.
Example: Logical OR operation with three digital inputs
The output signal (H1), an OR operation is then logic "1" if at least one or more
input signals (S. ..) have the state "1". The "1" stands for an actuated normally
open contact or a non-actuated normally closed contact.
True list:
S1 S2 S3
0 0 0
1 0 0
0 1 0
1 1 0
0 0 1
1 0 1
0 1 1
1 1 1
Logic algebra:
FBS:
H1
0
1
1
1
1
1
1
1
S1
S2
S3
H1 = S1 V S2 V S3
H1
Picture 3.15 OR operation
FBD
Picture 3.16 OR operation in FBD
64
3.2.4 AND before OR operation
The three switches to be logically combined in AND and OR:
The input of this logic is based on the fundamental rule of Boolean algebra:
Point are performed before addition and subtraction
In the implementation in the wiring logic, this means:
Series is going on in parallel
Example: It shows the implementation of a combined AND-OR circuit according to the rule
mentioned above:
True list:
S1
0
1
0
1
0
1
0
1
S2
0
0
1
1
0
0
1
1
S3
0
0
0
0
1
1
1
1
Logic algebra:
FBS:
H1
0
0
0
1
1
1
1
1
H1 = S1 & S2 V S3
S1
S2
H1
S3
Picture 3.17 AND before OR operation
FBD
Picture 3.18 AND before OR operation in FBD
65
3.2.5 OR before AND function
The four switches to be logically combined in OR and AND:
The input of this logic is also called conjunctive form. Since the Boolean rule applies here,
must be used with braces. Thus, it specifies that the OR operation is processed first.
The representation in the application program corresponds to the international standard IEC
61131.
Example: It shows the implementation of a combined AND-OR circuit according to the rule
mentioned above:
True list:
S1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
S2
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
S3
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
FBS:
S4
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
H1
0
0
0
0
0
1
1
1
0
1
1
1
0
1
1
1
Logic algebra:
H1 = (S1 V S2) & ( S3 V S4)
S1
S2
H1
S3
S4
Picture 3.19 OR before AND operation
FBD
Picture 3.20 OR before AND operation in FBD
66
3.1.4 OR-NOT operation (NOR)
Three switches should be logically linked in NOR:
The representation in the application program corresponds to the international standard IEC
61131.
Example: It shows the implementation of a combined NOR circuit according to the truth table:
True list:
Logic algebra:
FBS:
S1
0
1
0
1
S2
0
0
1
1
S3
0
0
0
0
H1
1
0
0
0
0
1
0
1
0
0
1
1
1
1
1
1
0
0
0
0
S1
S2
H1
S3
Picture 3.21 OR-NOT operation
FBD
Picture 3.22 OR-NOT operation in FBD
67
H1 = S1 V S2 V S3
3.2.7 Exclusive-OR (XOR)
The most used exclusive OR circuit, the Exclusive-OR circuit having two inputs.
It differs to the OR operation to the effect that the output only becomes "1" when one of the
two inputs are "1". If both inputs are "1", the output is "0".
With such a circuit you can realize an interlocking of two input signals very simply.
Example: Logical Exclusive-OR operation with two switches
True list:
S1
0
1
0
1
S2
0
0
1
1
Logic algebra:
FBS:
H1
0
1
1
0
S1
H1
S2
Picture 3.23 Exclusive-OR operation
FBD
Picture 3.24 Exclusive-OR operation in FBD
68
H1 = (S1 & S2) V ( S1 & S2)
Exercises: Logic blocks
FBD1a, FBD1b, FBD1c:
These logical links provides a good introduction to the FBD language of LRD12 or LRD20
from Lovato Electric
FBD 1c
FBD 1b
I1
Q1
&
I2
NA ND
I3
I3
&
I4
I2
I2
>1
=
>1
=
I3
Q2
Q2
I4
I4
&
I5
NOR
I5
I5
>1
=
=1
I6
I6
I6
LR D12
Picture 3.25
Exercise card FBD1a
&
LR D12
LR D12
Picture 3.26
Exercise card FBD1b
69
Picture 3.27
Exercise card FBD1c
3.2.8 Latching function
In control engineering, the latching function is often used. Especially when using buttons will
execute a stored function. A typical task is the on and off of a motor. The ON button is
always a contact and the OFF button always an opener. Why the OFF button is normally
closed, has something to do with the wire breakage. The VDE regulations state that in the
event of a wire break, the relevant section (e.g. a motor) must be switched off immediately
and must not be turned on.
To realize a latching function in the MicroSPS offers the LRD ... two variants.
1. The dynamic control of the output:
If the result of logic operation (RLO) = 1, then the output = 1
If the RLO = 0, the output = 0.
Picture 3.28 Dyn. latching function
2. The static control of the output:
Latching function with commands SET and RESET .
Both commands work with the positive edge.
Picture 3.29 Static latching function
In both examples, it is ensured that while pressing both buttons ON and OFF, the output = 0.
The wire breakage is protected , as in the case of a wire break in the "OFF" line drops the
output in any case.
70
Exercise: latching function
Sel bsthal tu ng /seal-i n-circu it
I3
Sta rt
>1
=
&
Q2
I4
FBD2a:
Latching with dynamic control of Q2.
(As in the contactor technology)
Sto pp
I5
S
I6
R
Q3
FBD2b:
Latching static drive of Q3.
(As with the conventional electronic controls on the flip-flops)
Bei der Programmerstellung ist auf
die Drahtbruchsicherheit zu achten!
In case of programming pay attention
to the fail-save circuit
LR D12
Picture 3.30 Exercise card FBD2a+b
71
3.3
Selection menu of the Function Blocks
In the FBD editor, the MicroPLC provides the same function as building blocks in the
LADDER editor.
Timer(Tx) Counter(Cx) RTC(x) ADD/SUB(AS) MUL/DIV(MD)
multiplexer(MX) Analog ramp(AR) data register(DR)
PID controller(PID)
Picture 3.31 Function blocks in FBD
3.3.1 Timing relay T
Start (Enable) input
Setpoint input "t"
switching output
actual value
actual value:
setpoint value:
Picture 3.32 Timer-Function block in FBD
Double-click on the block to reach the following window:
The timer offers 8 modes:
Time base: 0,01s / 0,1s / 1s / 1 Min.
time base
Setpoint time: 0,01s up 9999 Min.
actual value
setpoint value
Picture 3.33 Timer-Function block
Note:
The setpoint "Preset Value" of a timer can also come from an analog input or other device.
More in "processing analog values"
72
Mode 0: Internal coil (like a marker)
Mode 1: On-delay timer
Enable
Output
Picture 3.34a Timer Mode 1
Mode 2: On-delay timer with reset input. If the enable is off, the timer stops. Only if the
enable is switch "ON" again the timer continues to run.
Enable
Output
Reset
Picture 3.34b Timer Mode 2
Mode 3: OFF-delay timer. The rising edge of Enable (0 -> 1), the output is "ON". Time is
running out only when the enable the edge falls (1 -> 0). If enable is turned on again
during the running time, the value is set to "0". The timer can be restarted.
Enable
Output
Reset
Picture 3.34c Timer Mode 3
Mode 4: OFF-delay timer. If a falling edge of Enable (1 -> 0), the output is "ON" and the time
is running out. If enable is activated again during the elapsed time, the actual value
of the timer is reset to "0". The timer can be restarted.
Enable
Output
Picture 3.34d Timer Mode 4
73
Mode 5: Synchronous clock generator
The synchronous clock starts with the rising edge (0->1) and stops at the LOW edge
(1 -> 0) to enable. The ON-time and OFF-time on the output are the same.
Enable
Output
Picture 3.34e Timer Mode 5
Mode 6: Synchronous clock generator with reset
Enable
Output
Reset
Picture 3.34f Timer Mode 6
Mode 7: Asynchronous clock generator
The asynchronous clock starts with the rising edge (0 ->1) and stops at the LOW
edge (1 -> 0) to enable. The ON-time "t1" and the OFF-time "t2" at the output are
equal.
Enable
OFF
Output
OFF
ON
ON
OFF
t1
t2
ON
OFF
OFF
ON
OFF
Picture 3.34g Timer Mode 7
3.3.2 Pulse relay
A special function of the timing relay is the pulse relays or latching relay. This
function is shown in the diagram of the button:
Example: With the switch I1 can be the output by briefly pressing on Q1. A new brief press
of I1 Q1 turns off again.
Q1= ON
Picture 3.35 Pulse relay
Q1= OFF
Q1
74
Exercise: Timer relay
I2
FBD3:
With this exercise card all the modes of the timing relay
with internal setpoint (e.g. 10 s) should be implemented.
Enable
I4
Q2
Reset
Mode 1... 7
Pre Value: 10.00
Cur Value
Picture 3.36 Exercise card FBD3
I1
Wend e-Ste rn-Dreieckscha lter
reversin g sta r-delta swi tch
FBD 4
Sicherung
fuse
I2
STOPP
Stop
Q1
Rechtslauf
clockwise
I3
Rechts
right turn
Stern
star Q2
FBD4a:
This motor controller uses information given on the training
card inputs and outputs. The change from clockwise to
anti-clockwise rotation is only about stop and vice versa.
The time is 5 seconds.
I4
Links
left turn
Linkslauf
anti-clockwise
Q3
Dreieck
delta Q4
LR D12
Picture 3.37 Exercise card FBD4a
Ampel / Traffic light
LAD 7
FBD5 (like exercise LAD7):
In metropolitan areas, side road access to highways is
controlled in heavy traffic with a traffic light. The traffic light
shows RED when the main switch I01 is turned on.
An induction loop in the road surface before the traffic light
detects an incoming vehicle. With 1s delay starts the
traffic light cycle, which also takes 1 sec each for the
individual phases.
At the end of the traffic light cycle the lights are back on
RED. If the induction loop is connected constantly, so the
traffic lights cycle runs through the 1 sec intervals.
LR D12
Picture 3.38 Exercise card FBD7/5
75
3.3.3 Counter C
As with the timer the counter is a system component that needs to be configured simply. The
MicroPLC offers a total of 30 counter blocks, each with 8 different modes.
The presentation in the FBD editor provides the following information:
Counting input
Counting direction
Setpoint
switching output
actual value
actual value
setpoint value
Picture 3.39 Counter in FBD
Counter-No.:
The counter of LRD... Offers, like in
the Ladder diagram, 8 different modes:
Mode 0: internal coil (like a marker)
Picture 3.40a Counter mode1
Mode 1: up-down counter without overflow. If the setpoint = actual value the counting input is
disabled. The actual value is non-retentive. It loses its value when you turn off the
controller.
Setpoint input (0 ... 999999)
Variables specification (e.g.: the result of arithmetic)
Note:
Compared with the LAD circuit diagram, the counting coil, the output of the counter, the
counting direction and reset of the counter value in the FBD program be linked as shown in
the example:
76
Mode 2: up-down counter with overflow. If the setpoint = actual value of the count input is not
locked. The counter continues to count. The actual value is non-retentive. It loses its
value when you turn off the controller.
Note to "Reset Input" and "Direction Set" in Mode 2
•
•
"Reset input" has two functions. During counting up the reset is switched on, the
current value of the counter is set to "0". When pressed while counting down the
reset, then the setpoint "Preset Value" is set!
If the setpoint is reached when counting up the output switches of the counter. Now, if
the direction is switched, the output switches to "OFF" and again until the actual value
= "0", the output is switched to "ON". If the direction is switched on again, the output
switches back to "OFF" until the setpoint is reached again.
Example: Mode 2
Picture 3.40b Counter Mode 2
Mode 3: Like Mode 1, but the actual value is non-volatile. It stores its actual value when you
turn off the controller.
Mode 4: Like Mode 2, but the actual value is non-volatile. It stores its actual value when you
turn off the controller.
Mode 5: Like Mode 2, but with the reset value is always set to "0", regardless of the direction.
Mode 6: Like Mode 5, but non-volatile.
Mode 7: High-speed counter, which is used either as pure forward counter of the fast inputs
I1 or I2.
Mode 8: 1 KHz-speed counter, which is used purely as an up-counter on the inputs I1 and I2.
77
Exercise: Counter
FBD6a:
The counter C1 is to be counted on the input I2 forward. If the
value reaches 12, the counting should be interrupted. Only
after the counter is reset by I6, I2 can be recounted again.
Which mode is used to set?
zählen
CNT
I2
Count
Richtung
Sollwert
pre value
= 12
Direction
Mode
1 ... 8
I4
Q3
C1
löschen
I6
Reset
C1
Zähler / counter
FBD 6a/6b/6c
LR D12
Picture 3.41 Exercise card
FBD6a/6b/6c
I1
Sollwertvorgabe mit Vor-Rückwärtszähler
setpoint via up-down counter
LAD8a/8b / FBD7a /7b
Q1
START
Preset Value
FBD6b:
The exercise FBD6a is extended by the I3. With I3 can
change the direction of the counter.
a) How does Q3 behave when changing direction at the
switching output of the counter?
b) What happens if it is actuated while counting the
reset?
FBD6c:
Like the exercise FBD6b, now to be automated changes of
direction. If the counter reaches the value 12, it automatically
switches to count down. If the counter value reaches the
value "0", it switches back to counting up. It is changing until
the count clock of
0.5 Hz is switched off by I02.
FBD7a:
Using an up-down counter of the target value for a timer
from 0 to 50 sec ... To be adjustable. As the adjustment
buttons Z keys are used with Z01 is forward (UP), with Z03
backward (DOWN) counted.
FBD7b: Extension
The setpoint and the actual value of the timer should be
displayed on the display of the LRD.
Timer 2
Counter
UP
DOWN
Min=0
Max=50
LR D20
Picture 3.42 Exercise card FBD7a+b
78
3.3.4 Shift register S01
The function block "shift register S01" is a bit shift register and is available once. It can
maximum be 8 steps high.
Enable
Sift input
Picture 3.43 Shift register in FBD
The start-coil "Start Coil" defines the
first step in the shift register. It can be
an output (Q, Y) or relays (M, N).
If you have decided on a variable, all
outputs or marker that have been
defined with "Select 1-8", assigned.
Picture 3.44 Shift register menu
In this example, the outputs Q1-Q4 are occupied by the shift register The shift register
operates as a ring shift register. This means in this example that the fourth time clock with
the the input I02 the output Q01 is "ON" again.
Exercise: Shift register
„Start Coil“
Q01
Q02
Q03
Q04
Picture 3.45 Exercise FBD8a
FBD8b:
Create accordance with the exercise FBD5 with shift register.
79
3.3.5 Analog comparator G
The 24VDC base unit LRD ... offers two analog inputs A1 and A2. The analog value of from 0
to 10V is applied to an analog to digital converter on the inputs, and converted into a binary
number. The converted value can be compared over the analog values to comparator block
G with different values.
The analog comparator values offers 8 modes, the mode 0 is always an internal coil.
Mode 1: (Ay-Ref.) <= Ax <= (Ay+Ref.)
Ax and Ay can be assigned different.
With the direct assignment to the potentiometer of the MiniTrainer you can easily try out the
formula.
Example:
Ax = A01(0…10V)
Ay = e.g.: 7V
Ref.= 2V
d.h.:
5V <= Ax <= 9V
Picture 3.46 Example Analog comparator
If the reference value is set to 2V and you turn the potentiometer A1, then the output of the
analog comparator is switch on at 5V, and switch off at 9V again.
Mode 2: (Ax <= Ay)
The output of the block "G" is "ON" when the analog value of A1 is less than or equal to the
value of A2.
A1
A2
Ax = Adjustable example via the potentiometer A1
Ay = Adjustable example via the potentiometer A2
Picture 3.47 Potentiometer on the MiniTrainer(XL)
Additional functions:
Mode 3: (Ax> = Ay) Ax greater than, equal Ay
Mode 4: (Ax <= ref) Ax less than, equal a fixed value.
Mode 5: (Ax >= Ref.) Ax greater than, equal a fixed value.
Mode 6: (Ax = Ref.) Ax equal a fixed value.
Mode 7: (Ax> <ref) Ax smaller or larger but not the same.
80
Exercise: Analog comparator
Ana log werteverg lei cher
Anal og compa rator
FBD 9a +b
Q1
0,5Hz
FBD9a+b:
a) Two analog values to be compared. Once the
comparator output is ON, Q2 is on and Q1 flashing at
0.5 Hz.
Q2
Ax >= Ay (Mode …)
b) In this exercise AI01 should be compared to a
constant value of 25 according to the sketch (mode ....).
Ai01 >= Ai02
Ai01
500
01
02
LR D12
Picture 3.48 Exercise card FBD9a+b
Q2=“1“
0
Wende -Stern -Drei eckscha lter
re versin g star-d elta swi tch
FBD 9c
I1
Sicherung
fuse
Q1
Rechtslauf
clockwise
I2
STOPP
Stop
I3
Rechts
right turn
Stern
star Q2
value= 25
FBD9c:
This motor controller is using the informations given from the
training card inputs and outputs. The change from clockwise to
anti-clockwise rotation is only about stop and vice versa. The star
to delta transition time is variably adjustable via the analog input
A1 between 5 and 20s.
I4
Links
left turn
Linkslauf
Q3
anti-clockwise
A1
5
20s
Note:
Since the potentiometer A1 is not of MiniTrainer very accurate,
the maximum value in result cannot be achieved exactly 20s.
Dreieck
delta Q4
LRD12
Picture 3.49 Exercise card FBD9c
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3.3.6 Multiplexer MX
Each of the 30 multiplexers provide the ability to assign up to 4 variable to a setpoint input.
The query variable is binary, using two bits.
The program example will illustrate this:
The timer T01 to run at 4 different times depending on the application. The four variables
(setpoints) are to be preselectable by the two inputs I2 and I3.
Prefix:
(Vorwahl)
I2
I3
0
1
0
1
0
0
1
1
Setpoints V1…3
10
15
20
25
Depending on the switch combination of I2
and I3 the corresponding setpoint is
assigned to the timer T01. The setpoint input
of the timer module T01 is connected to the
output of the multiplexer block MX01.
Picture 3.50 MX function block
Picture 3.51 Exercise Multiplexer FBD10
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3.3.7 Boolean function BL
The MicroPLC offers a Boolean logic unit. The standard block can be 4 digital input signals
combined (16 possibilities).
Input 1
Input 2
Input 3
Input 4
Output
Picture 3.52 BL function block in FBD
The 16 possibilities are represented in binary code:
Picture 3.53 BL Binary code
The output of the block is one bit and can be optionally specified with "1" or "0".
Example: Using the BL block to create a code lock. The code consists of a number between
0 and 9 (1 decade). If the code is correct, the output Q01 of 0.5 s will be "ON".
0
2
2
2
1
2
4
=2
=4
=8
Picture 3.54 Exercise code lock FBD11
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Exercise: Boolean Functions
I2
I3
=1
Q3
FBD12
Based on the training card you will be programming a Boolean
block for an exclusive OR with 4 inputs. That is, the output of Q01
is "1" if only one input is "1".
I4
I5
XOR mit 4 Eingängen
XOR with 4 inputs
FBD12
LR D20
Picture 3.55 Exercise card FBD12
84
3.3.8 Pulse-width modulation (PWM) P
The MicroSPS with transistor outputs offers the option of the digital output Q01 via the pulse
width modulation block (P) to drive.
The PWM block offers two modes:
Mode 1:
Enable
Sel 1
Sel 2
Level 0
Q01
Picture 3.57 P function block in FBD (Mode 1)
Pulse width modulation is a convenient way to have a
digital output, e.g. a frequency converter to control a motor
in the speed or control.
Picture 3.56 P Menu Mode 1
To get to know this function, you can realize a simple link. It performs both analog signals A1
and A2 of the MiniTrainers as set values (preset value) to the module. This is done by setting
the variable type "A" by selecting the "Preset Type". Where A1 is the time in milliseconds
(ms) for the frequency and A2, the time indication for the high signal also in milliseconds.
Selection of profiles
Note:
"T" must be always greater than "t" and can not be
"0", that is, A01 must always be greater than A02.
Picture 3.58 P Menu Mode 1
If you choose, however, the variable Type "N" then constant values can be used (0. 32767)
for the profile of "T" and "t" to enter. Select 1 is always the profile that is activated by enable.
The two inputs Sel1 and Sel2 of the PWM module allow an additional two profiles retrieve.
FBD 13:
I1 = Enable = Select 1 = T= 200ms t=50ms I2 = Select 2: T= 400ms t=50ms
I3 = Selekt 3: T= 400ms
t=10ms I4 = Stop
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Mode 2:
In Mode 2, a frequency PF is output (in Hz) for a predetermined time period PN.
Enable
Q01
Picture 3.59 P function block in FBD (Mode 2)
FBD 13a
For testing the function both
analog inputs of the
MiniTrainers are used:
Picture 3.60 PWM funktions
Exercise: PWM
Sil o / Tan k
FBD1 4
I1
Start/Stopp
PWM
Q1
M
Silo / tank
Voll
Enable
Q3
IA1
FBD14:
This exercise is to regulate a pump for filling a tank.
The level is recorded as a measure via the analog input IA1.
The tank is emptied through the manual outlet, the filling level
and the analog value is lowered and falls to 0V. With the input
I1, the system is switched on and off.
The pump controller consists of the release of Q3 and the
PWM - output Q1.
If the level reading reached IA1 the value of 9.5 V, the release
of Q3 is removed.
The fuller the tank, the slower the pump. If the tank is empty,
the pump runs at full speed. If the tank is full, the speed is
zero.
LR D12
Picture 3.61 Exercise card FBD14
IA1= ~10V
0V
~0,5Hz …………………….~500Hz (PWM)
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3.3.9 Text H
The text block can be used 30x. Mode1 means with display and Mode2 means without
display
Enable
Picture 3.62 H Text block
The editor for text entry is located, as in the LAD editor, in the "Edit" menu -> "HMI / Text"
Picture 3.63 Text Input
3.3.10 Display backlight
The display of the LRD ... can remain switched
on for the program. For this, the menu offers
"Operation" in the stop mode or in offline mode
from the submenu:
"Module System Set ..." the possibility of
program-related backlight
Picture 3.64 To adjust the backlight
Picture 3.65 Display backlight
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