a
AN-535
APPLICATION NOTE
One Technology Way • P.O. Box 9106 • Norwood, MA 02062-9106 • 781/329-4700 • World Wide Web Site: http://www.analog.com
Digital Input/Output Subsystems
INTRODUCTION
The DB-16 and DB-24 are 16- and 24-channel digital I/O
subsystems providing a reliable, solid state, optically
isolated interface between data acquisition boards, such
as the Analog Devices’ RTI-800 series, or distributed I/O
signal conditioning subsystems such as the Analog
Devices’ Model 6B50, and discrete high level I/O.
DB-16 Digital I/O Subsystem
Use the DB-16 Digital I/O Backplane, shown in Figure 1,
and its associated ac and dc single-channel I/O modules
to measure and/or control high level ac and dc signals or
if isolation of the digital I/O is required.
Single-Channel Solid State Relays
The DB-16 supports the installation of up to 16 singlechannel, solid-state relay modules, which provide
2500 V peak of optical isolation. You should install the
modules in their appropriate positions in the backplane
and secure them with one screw each.
The DB-16 is a manifold card that accepts up to 16
single-channel digital input and output modules. These
solid state relay modules can be mixed and matched to
provide an interface to ac inputs, ac outputs, dc inputs
and dc outputs. Each I/O module is individually controlled or sensed by the digital I/O of the data acquisition
board or the 6B50 subsystem.
All output modules can switch up to three amps. AC output modules provide zero voltage turn-on and have an
RC (resistor-capacitor) snubber network for increased
capability with inductive loads. AC and dc input modules are designed with filtering on the input and hysteresis for high noise rejection and transient-free “clean”
switching. They are designed so that high voltage transients on the input do not cause damage to the module.
The DB-24 is a manifold card that can accept up to six
4-channel (quad) digital input and output modules.
These modules can be mixed and matched as well. Each
module handles four channels of identical levels, and
the state of each input or output can be observed via the
four LEDs on each module.
Each module operates by negative true logic, in which a
low digital voltage turns on current to the module. Individual LED status indicators monitor module activity
and light when the current is ACTIVE.
The DB-16 and DB-24 share the same pinout and 50-pin
card edge connector and can be used interchangeably.
However, only the 16 channels are addressable on the
DB-16. An external +5 V dc power supply at 300 mA
maximum is required for operation.
Each I/O module position on the DB-16 backplane has
a 5 amp, 250 V rms pico-fuse (Littelfuse® Part Number
251 005) protecting the module and wiring from short
circuits.
All trademarks are the property of their respective holders.
BARRIER STRIP FOR
LOGIC SUPPLY INPUT
POWER BARRIER
STRIP
49
POWER LINE
FUSE, 5 AMP
SIGNAL CARD EDGE
CONNECTOR
KEY
SLOT
1
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
PULL-UP RESISTOR
3.3kV
Figure 1. DB-16 Digital I/O Backplane
15
AN-535
Table I lists the input and output modules available for
use with the DB-16 backplane.
Attaching Digital I/O Applications to the DB-16
Backplane
The DB-16 backplane is powered through an external
+5 V dc power supply. Applications to the DB-16 backplane are connected through the screw terminal barrier
strip, which contains 32 standard slot-head screw terminals (screw terminals 1 and 2 are associated with channel 0 on the backplane; screw terminals 3 and 4 are
associated with channel 1 on the backplane, and so on).
Use the odd-numbered screw terminal for the high input; use the even-numbered screw terminal for the low
input.
Table I. Single-Channel Input/Output Module Summary
Output
Current
Type
Model
Range
Input
ID016
ID032
IA140A
4 V–16 V dc
10 V–32 V dc
90 V–140 V ac
90 V–140 V dc
180 V–280 V dc
180 V–280 V ac
IA280A
Output OD060
OA140A
OA280A
5 V–60 V dc
12 V–140 V ac
24 V–280 V ac
Input
Current
68 mA
34 mA
5 mA
5 mA
Figure 2 illustrates high level ac and dc digital wiring using input and output modules on the DB-16 backplane.
Example 2a illustrates turning a lamp on or off; example
2b illustrates monitoring whether the lamp is on or off;
example 2c illustrates turning a relay coil on and off; and
example 2d illustrates monitoring whether or not a relay
coil is energized.
3.0 A rms
3.5 A rms
3.5 A rms
115V AC
SCREW
#31
LED
115V AC
CURRENT
LIMIT
RESISTOR1
SCREW
#29
LED
OUTPUT MODULE4
15
INPUT MODULE4
14
#30
#32
PULL-UP
RESISTOR
SOCKETED
PICO FUSE (5A)
b. AC Input
a. AC Output
+24V DC
115V DC
SCREW
#27
LED
2
SCREW
#25
RELAY
COIL3
LED
OUTPUT MODULE4
13
INPUT MODULE4
12
#26
#28
c. DC Output
d. DC Input
NOTES:
1SHOULD NOT EXCEED 3A.
2USER SUPPLIED DIODE NECESSARY FOR INDUCTIVE SPIKE DAMPING.
3RELAY COIL AMPERAGE SHOULD NOT EXCEED OUTPUT MODULE RATING.
4MODULES ARE COLOR CODED: AC INPUT
– YELLOW
AC OUTPUT – BLACK
DC INPUT – WHITE
DC OUTPUT – RED
Figure 2. Typical High-Level Digital I/O Wiring Examples Using the DB-16 Backplane
–2–
AN-535
1
2
C
C
3
4
5
6
C
C
7 9 C 11
8 10 C 12
13 C 15 17 C 19 21 C 23
14 C 16 18 C 20 22 C 24
BARRIER
STRIP
FUSE
5A
FUSE
1A
1
3
1
3
1
3
1
3
1
3
1
3
2
4
2
4
2
4
2
4
2
4
2
4
0–3
4–7
8–11
49
J1
12–15
20–23
KEY
SLOT
1
25
+5V AND
GND
16–19
23
TO DIGITAL I/O
CONNECTOR
Figure 3. DB-24 Digital I/O Backplane
DB-24 Digital I/O Subsystem
Use the DB-24 Digital I/O manifold card, shown in Figure
3, and its associated dc and ac 4-channel I/O modules to
measure and/or control high level ac and dc signals or if
isolation of the digital I/O is required.
provided to apply colored stick-on dots (supplied) to
match the color coding of the modules (yellow = ac input, black = ac output, white = dc input, and red = dc
output). Note that the four channels corresponding to
one quad module must be configured with either all input channels or all output channels.
4-Channel Solid State Relays
The DB-24 is a 24-channel I/O backplane that supports
the installation of up to six 4-channel, high-density modules to perform ac input, dc input, dc output, and dc output functions. You install each module into a socketed
position on the DB-24 backplane, where each module
is held in place with two screws, provided with the
module.
Each module on the DB-24 Digital I/O Backplane operates by negative true logic, in which a low digital voltage
turns on current to the module. Four LEDs on each module indicate the status of the I/O channels (the LED lights
when current is turned on).
Each I/O module position has two 5 amp, 250 V rms picofuses protecting the module and wiring from short circuits. Table II lists the input and output 4-channel
modules available for use with the DB-24 backplane.
All output modules are able to switch up to 3 amps. AC
output modules provide zero voltage turn-on and have
an RC snubber network for increased capability with inductive loads. AC and dc input modules are designed
with filtering on the input and hysteresis for high noise
rejection and transient free “clean” switching. They are
designed so that high voltage transients on the input
will not cause damage to the module. Optical isolation
for the ac and dc input and output module is rated at
4000 V rms input-to-output.
Table II. Quad Input/Output Module Summary
Type
Model
Range
Input
ID16FQ
ID32Q
IA120QA
4 V–32 V dc
10 V–60 V dc
90 V–140 V ac
90 V–140 V dc
180 V–280 V dc
180 V–280 V ac
IA240QA
Each module is color-coded by function and the model
number is clearly marked on the module itself. The
channel numbers associated with the module are
printed below the module on the panel and spaces are
Output
–3–
OA240QA
OD60Q
24 V–280 V ac
3 V–60 V ac
Output
Current
Input
Current
68 mA
34 mA
5 mA
5 mA
3.5 A rms
3.5 A rms
AN-535
To configure the DB-24 backplane for external power,
ensure that the socketed 1 amp fuse is installed to the
left of the +5 V dc and GND screw terminals. Refer to
Figure 4.
Powering the DB-24 Backplane
You can power the DB-24 Digital I/O Backplane internally
for some boards, or you can use an external +5 V power
supply. Before you attach the DB-24 backplane to the
board, you must configure it for internal or external
power.
Attaching the DB-24 Digital I/O Backplane
To attach the DB-24 backplane to a data acquisition or
6B50 board, use a 50-pin cable, such as the AC1585-9
cable or the CAB-03 cable (available from Analog
Devices). Attach one end of the cable to the digital I/O
connector on the board and attach the other end of the
cable to the digital I/O connector (J1) on the DB-24 backplane. Make sure that Pin 1 on the cable corresponds to
Pin 1 on the connector. Refer to Figure 5.
To configure the DB-24 for internal power, remove the
socketed 1 amp fuse from the left of the +5 V dc and
GND screw terminals. Install this fuse in the socketed
position to the right of the +5 V dc and GND screw terminals on the DB-24 backplane.
INSTALL 1A FUSE
FOR EXTERNAL POWER
1
3
1
3
1
3
1
3
1
3
1
3
2
4
2
4
2
4
2
4
2
4
2
4
0–3
4–7
8–11
12–15
16–19
20–23
KEY
SLOT
J1
49
+5V
EXTERNAL
POWER
SUPPLY
25
23
1
INSTALL 1A FUSE
FOR INTERNAL POWER
Figure 4. Positioning Fuse for Internal or External Power on the DB-24 Backplane
1
3
1
3
1
3
1
3
1
3
1
3
2
4
2
4
2
4
2
4
2
4
2
4
DB-24
BACKPLANE
PIN 1
PIN 1
BOARD
CAB-03 OR
AC1585-9
CABLE
J1 CONNECTOR
Figure 5. Attaching the DB-24 Digital I/O Backplane
–4–
AN-535
Attaching Digital I/O Applications to the DB-24 I/O
Backplane
Use the DB-24 Digital I/O Backplane for high level ac or
dc signals. Connect applications to the backplane
through the barrier strip. The barrier strip contains standard slot-head screw terminals, six screws for each
4-channel (quad) I/O module. Use 22-14 AWG twistedpair wire, and strip the wire back approximately
0.25-inch (6.3 mm). Four consecutive input or output applications are attached to a single quad module, with
two channels sharing the same common in the module.
1
2
C
C
I/O
CHANNEL COMMON
3
4
1
2
The two common connections for each module are connected to one another on the DB-24 backplane. Therefore, each of the four individual channels on the module
can use either of its two common connections. Since the
commons are connected, you must make sure that all of
the applications attached to a 4-channel module share
the same common voltage reference. If two applications
use different common voltage references, the applications must be attached to two different modules. Figure
6 illustrates how the channels and their commons are
connected.
1
3
2
4
C
3
C
4
1
8
2
9
3
10
0–3
Figure 6. DB-24 Backplane Common Connections
Figure 7 illustrates high level ac and dc digital wiring using input and output modules on the DB-24 backplane.
Example 7a illustrates turning a lamp on and off, and
example 7b illustrates monitoring whether the lamp is
on or off. Example 7c illustrates turning a relay coil on
and off, and example 7d illustrates monitoring whether
or not the relay coil is being energized.
NOTE:
The channels on the screw terminals on the DB-24 backplane are labeled from 1–24, while the channels for the
I/O modules are labeled 0–23. Keep this distinction in
mind when installing your field wiring applications.
RELAY
COIL3
115V AC
CURRENT
LIMIT
RESISTOR1
115V AC
IL
1
2
115V DC
+24V DC
2
C
C
3
4
1
2
C
C
3
4
1
2
C
C
3
4
1
2
C
C
1
3
1
3
1
3
1
3
2
4
2
4
2
4
2
4
3
4
0–3
0–3
0–3
0–3
a. AC Output
b. AC Input
c. DC Output
d. DC Input
NOTES:
1SHOULD NOT EXCEED 3A.
2USER SUPPLIED DIODE NECESSARY FOR INDUCTIVE SPIKE DAMPING.
3RELAY COIL AMPERAGE SHOULD NOT EXCEED OUTPUT MODULE RATING.
4MODULES ARE COLOR CODED: AC INPUT – YELLOW
AC OUTPUT – BLACK
DC INPUT – WHITE
DC OUTPUT– RED
Figure 7. Typical High Level Digital I/O Wiring Using the DB-24 and 4-Channel Solid State Relay Modules
–5–
AN-535
POWER INPUT/OUTPUT
LOGIC SUPPLY
BARRIER STRIP
1
2
3
4
5
6
7
8
9 10
11 12
13 14
15 16
17 18
19 20
21 22
23 24
25 26
27 28
29 30
31 32
–
+
5 AMP
FUSE (24)
EDGE CONN
BOTTOM
ALL
LOGIC GND EVEN
PINS
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
1
2
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
TOP
+LOGIC
1
17
19
21
23
25
27
29
SIGNAL 31
INPUT/OUTPUT 33
35
37
39
41
43
45
47
+LOGIC 49
PULL-UP
RESISTOR
3.3kV
(24)
LED
INDICATOR
(24)
Figure 8. Schematic Diagram Model DB-16
1
2
C
3
5
C
4
6
C
9
7
C
8
10
C
11
C
13
12 14
C
15
C
17
16 18
C
19
21
C
C
20 22
LOWER POWER
BARRIER STRIP
23
C
24
UPPER POWER
BARRIER STRIP
5 AMP
FUSES (12)
1
8
1
8
1
8
1
8
1
8
1
2
9
2
9
2
9
2
9
2
9
2
8
9
3
10
3
10
3
10
3
10
3
10
3
10
4
11
4
11
4
11
4
11
4
11
4
11
5
12
5
12
5
12
5
12
5
12
5
12
6
13
6
13
6
13
6
13
6
13
6
13
7
14
7
14
7
14
7
14
7
14
7
14
1 AMP
FUSE
+ –
49
47
45 43
41
39
37 35
33
31
29 27
25
23
21 19
17
15
13 11
SIGNAL INPUT/OUTPUT EDGE CONNECTOR
Figure 9. Schematic Diagram Model DB-24
–6–
9
7
5
3
1
PINS 2-50
TIED TO COM
AN-535
SINGLE-CHANNEL SOLID STATE RELAYS
MOUNTING
BACKPLANE
MOUNTING
BACKPLANE
PLUG-IN MODULE
AC INPUT
AC HI
INPUT
AC OUTPUT
AC HI
OUTPUT
LOAD
SCREW
TERMINALS
AC LO
INPUT
SCREW
TERMINALS
FUSE
LED
+VCC
PLUG-IN MODULE
LED
+
+VCC
3.3kV
ZERO
VOLTAGE
CIRCUIT
FUSE
AC LO
OUTPUT
12kV
220V
+ 220V
3.3kV
DOUT
EDGE
CONNECTOR
DIN
EDGE
CONNECTOR
DIG GND
a. AC Input Module
MOUNTING
BACKPLANE
COMMUTATING MOUNTING
DIODE
BACKPLANE
PLUG-IN MODULE
DC INPUT
DC HI
INPUT
SCREW
TERMINALS
DC LO
INPUT
b. AC Output Module
DC HI
OUTPUT
PLUG-IN MODULE
DC OUTPUT
+
LOAD
SCREW
TERMINALS
1kV
FUSE
FUSE
DC LO
OUTPUT
AMPLIFIER
LED
+VCC
LED
+
3.3kV
+VCC
RC
+
RC
3.3kV
DOUT
EDGE
CONNECTOR
DIN
IOUT
EDGE
CONNECTOR
DIG GND
c. DC Input Module
b. DC Output Module
Figure 10.
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
1.7 (43.2)
1.0 (25.4)
4-40 HOLD
DOWN SCREW
1.25
(31.8)
0.25 (6.4)
5 4 3
2
1
0.6
(15.2)
0.1 (2.54) GRID
–7–
AN-535
SCHEMATIC DRAWINGS
OUT
4
+VCC
IN
4
IN
4
+VCC
OUT
4
IN
3
COMMON
COMMON
SNUB
SNUB
SNUB
SNUB
OUT
3
E3298–5–4/98
LOGIC OUT
GND
3
IN
3
IN
1
IN
2
+VCC
OUT
2
COMMON
OUT
1
Figure 12. AC Output Module, OA240QA
R1
LOGIC OUT
GND
3
OUT
4
+VCC
IN
4
COMMON
IN
3
IN
4
IN
1
IN
2
+VCC
OUT
4 (–)
COMMON (+)
OUT
3 (–)
IN
3
Figure 11. Input Modules, ID16FQ, ID32Q, IA120QA,
IA24QA
+VCC
OUT
2 (–)
COMMON (+)
OUT
1 (–)
Figure 13. DC Output Module, OD60Q
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
Tolerance: ±0.020 (±0.50)
1.9 (47.5)
0.2
(5.1)
13 12 11
0.45
(11.43)
0.2
(5.1)
10 9 8
2.9
(73.2)
0.5
(12.7)
6 5
4
3 2 1
0.3 (7.6)
0.2 (5.1)
0.4 (10.2)
0.9 (22.9)
1.1 (27.9)
1.3 (33.0)
0.042 (1.1) DIA. PINS
2.1 (53.3)
4–40 3 0.75 (19.1) PAN HEAD SCREW
CASE COLORS:
INPUT MODULES:
AC: YELLOW
DC: WHITE
OUTPUT MODULES: AC: BLACK
DC: RED
–8–
PRINTED IN U.S.A.
0.125R