MBMA340
Software Driver for
SIMATIC® S7-300/400 Controllers with
Serial Communication Processor CP340
MODBUS™ RTU Protocol
S7 Controller becomes Modbus Master
Manual
Version 2.00
1
Contents
1
Contents ....................................................................................................................................... 2
2
Disclaimer .................................................................................................................................... 3
3
Application Possibilities .............................................................................................................. 3
4
Functionality ................................................................................................................................ 4
5
Supplied software function blocks ............................................................................................... 4
5.1
5.1.1
FB10 “MBMAREQ” function block ................................................................................... 4
5.2
FB10 “MBMAREQ” parameters description .................................................................. 5
5.2.1
FB34 “MBMA340” function block ..................................................................................... 8
6
FB34 “MBMA340” parameters description .................................................................... 8
Preparing the user program .......................................................................................................... 9
STEP7 HW-Config .............................................................................................................. 9
6.2
STEP7 Project program blocks .......................................................................................... 10
7
6.1
Supported Modbus Function Codes with program example...................................................... 11
7.1
Function Code 01 - Read Coil Status ................................................................................. 12
7.2
Function Code 02 - Read Input Status ............................................................................... 12
7.3
Function Code 03 - Read Output Registers ....................................................................... 12
7.4
Function Code 04 - Read Input Registers .......................................................................... 12
7.5
Function Code 05 - Force Single Coil ............................................................................... 13
7.6
Function Code 06 - Write Single Register ......................................................................... 13
7.7
Function Code 15 - Force Multiple Coils .......................................................................... 13
7.8
Function Code 16 - Write Multiple Registers .................................................................... 13
8
Performance ............................................................................................................................... 14
9
Trouble shooting ........................................................................................................................ 14
10
Service and Support ................................................................................................................... 15
MBMA340 Software driver for S7-300/400 controllers with serial communication processor module CP340 / Modbus RTU Protocol
Manual V2.00 English
Page 2 of 15
2
Disclaimer
THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
ALL TRADEMARKS MENTIONED IN THIS MANUAL ARE PROPERTY OF THEIR
RESPECTIVE OWNERS
3
Application Possibilities
This software package implements the GOULD MODBUS RTU protocol on SIMATIC S7-300/400
controllers with a Point-to-Point (PtP) serial communication processor module. The SIMATIC S7
becomes the Modbus Master.
Supported Communication Processor (CP) module
 CP340
The CP340 is supplied with the following protocol drivers
 3964(R) driver
 ASCII driver
 Printer driver
The software function blocks in this package use a protocol adaption with the ASCII driver in order
to provide you with the
 Modbus Master RTU driver
With this additional software driver many Modbus Slave devices supporting the Modbus RTU
protocol can be connected to the CP340 of your SIMATIC S7-300/400 station. Typical Modbus
Slaves, but not limited to the below, are





Energy Power Meters
Valves
Variable Frequency Drives (VFD’s)
Vibration Monitoring Systems (VMS’s)
PLC’s
MBMA340 Software driver for S7-300/400 controllers with serial communication processor module CP340 / Modbus RTU Protocol
Manual V2.00 English
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4
Functionality
The Modbus Master is the active partner in this asynchronous communication while the Modbus
Slave remains always passive. The Master is sending its requests one by one to the connected Slave
and waits for a reply or timeout from the Slave before processing the next request.
All requests will be configured by the programmer in the user program and then cyclically
processed by the communication driver.
The following Modbus function codes are supported:








5
Function Code 01 - Read Coil Status
Function Code 02 - Read Input Status
Function Code 03 - Read Output Registers
Function Code 04 - Read Input Registers
Function Code 05 - Force Single Coil
Function Code 06 - Write Single Register
Function Code 15 - Force Multiple Coils
Function Code 16 - Write Multiple Registers
Supplied software function blocks
The software driver comes as project archive MBMA340.ZIP which needs to be retrieved with the
Simatic Manager software. That project is a working example and will support the programmer as a
reference to his own implementation.
The project archive software consists of total four function blocks




5.1
FB10
FB2
FB3
FB34
“MBMAREQ”
“P_RCV”
“P_SEND”
“MBMA340”
Modbus Master Request function block
Siemens standard receive function block for CP340
Siemens standard send function block for CP340
Modbus Master Communication function block
FB10 “MBMAREQ” function block
All Modbus Master Requests need to be configured in the user program by calling the FB10
“MBMAREQ” function block. Although it is important to know about the different Modbus
Function Codes this function block uses Modbus addresses instead only for configuring a request.
That makes its handling easier for beginners.
MBMA340 Software driver for S7-300/400 controllers with serial communication processor module CP340 / Modbus RTU Protocol
Manual V2.00 English
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5.1.1
FB10 “MBMAREQ” parameters description
INSTANCE DATA BLOCK
Each function block needs an individual instance data block.
Input parameters:
Name:
Type:
Default:
Description:
RW
BOOL FALSE
READ/WRITE (0=READ, 1=WRITE)
For reading data from the slave this input should be set to FALSE.
For writing data from the CPU to the slave this input should be TRUE.
SLAVE
INT
1
Here the address of the connected Modbus slave needs to be specified.
Possible entries are values between 1 and 255.
The Modbus address 255 is reserved for broadcasting data to all connected
Slaves (only possible, when more than one Modbus slave is connected to
the CP in a “Multi-drop” RS-485/422 network configuration).
START
DINT
40001
Defines the Modbus start register in the Modbus Salve
The following addresses are possible:
00001 – 09999
10001 – 19999
30001 – 39999
40001 – 49999
END
DINT
40001
Outputs/Coils
Inputs
16 bit input registers
16 bit output registers/holding registers
Defines the last register in the Modbus slave to be addressed.
The address range is the same as for the START input parameter.
MBMA340 Software driver for S7-300/400 controllers with serial communication processor module CP340 / Modbus RTU Protocol
Manual V2.00 English
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WRMODE
BOOL 0
Modbus offers two different function codes with the same result if the
User wants to write a single register to the slave. So this parameter is only
valid if the RW input parameter is set to TRUE=WRITE and the specified
START and END parameters are the same.
When this parameter set to FALSE=AUTO the function block will
perform a single register request.
If it is set to TRUE=MULTIPLE the function block will perform a multiple
registers request for one register only.
S7ADDR
POINTER
Defines the first address byte within the CPU for the Modbus data to be
stored into or data sent from to the slave. The address can be located in the
following areas of the CPU only:




Inputs
Outputs
Memory
Data block
Example of any pointer format
P#DB11.DBX0.0 BYTE 1
The bit address and the byte format specify the location in the S7 controller.
A length parameter must be entered as well but will be ignored.
The driver does not check the availability of the entered address.
FORMAT
INT
0
Optional formatting function for received Modbus data.
0 = NONE
1 = LOHI (swapping between low- and high byte)
LINK
WORD 0
This input parameter has to be connected to the LINK output parameter of
the “MBMA340” communication function block.
Output parameters:
Name:
Type:
Description:
DONE
BOOL
This output is set if the Modbus Request has been successfully executed
without any error.
ERROR
BOOL
This output is set if any error occurred in the execution of the Modbus
Request or any parameterization failure is detected.
Further information can be retrieved by evaluating the STATUS parameter.
STATUS
WORD
This output parameter will indicate errors occurred during the execution of
the Modbus request. In case of an error it will give an error code.
For identification the error code refer to the error table below.
Note: All output parameters are only available for one CPU cycle.
MBMA340 Software driver for S7-300/400 controllers with serial communication processor module CP340 / Modbus RTU Protocol
Manual V2.00 English
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FB10 “MBMAREQ” Error status table:
Parameter
Value (Hex)
Description
STATUS
0000h
No failure
STATUS
E001h
Slave address out of range
STATUS
E002h
START and/or END parameter out of range
STATUS
E003h
Number of registers is out of range
For accessing outputs/coils (00001 - 09999) or inputs (10001 - 19999)
the max. total is 2040
For the 16 bit input registers (30001 - 39999) or 16 bit output/holding
registers (40001 - 49999) the max. total is 127
STATUS
E004h
Request cannot be performed
Inputs (10001 - 19999) and 16 bit input registers (30001 - 39999) are read
only addresses
STATUS
E005h
Specified S7ADDR is not valid
STATUS
E006h
LINK parameter mismatch with MBMA340 communication function block
STATUS
0E50h
Received slave address not correct
STATUS
0E51h
Received function code not correct
STATUS
0E52h
Byte underflow
STATUS
0E53h
Byte overflow
STATUS
0E54h
Received byte counter underflow
STATUS
0E55h
Received byte counter overflow
STATUS
0E57h
CRC checksum error
MBMA340 Software driver for S7-300/400 controllers with serial communication processor module CP340 / Modbus RTU Protocol
Manual V2.00 English
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5.2
FB34 “MBMA340” function block
The Modbus Master Function block FB34 “MBMA340” is adapting the Modbus RTU Protocol and
is processing the requests configured with the “MBMAREQ” function block one by one. The user
need to supply the block at the LADDR input parameter with the hardware address of the CP340
same as configured in the hardware configuration. The LINK parameter of has to match to all
correspondent “MBMAREQ” function blocks. The WDTIME parameter is a watchdog/timeout
time, maximum waiting time for a slave response before processing the next request.
5.2.1
FB34 “MBMA340” parameters description
INSTANCE DATA BLOCK
Each function block needs an individual instance data block.
Input parameters:
Name:
Type:
Default:
Description:
LADDR
INT
256
Defines the hardware I/O address of the communication processor (CP).
This address has to match with the address set in in the HWConfig of the
project.
WDTIME
TIME
T#2s
This is a watchdog timeout time. The time specifies the maximum waiting
time for a response from the Modbus slave.
Output parameters:
Name:
Type:
Description:
LINK
WORD 0
This output parameter has to be connected to the LINK input parameter of
the “MBMAREQ” function block.
Standard function blocks:
This function block utilizes the Siemens standard function blocks FB2 “P_RCV” and FB3 “P_SEND”.
MBMA340 Software driver for S7-300/400 controllers with serial communication processor module CP340 / Modbus RTU Protocol
Manual V2.00 English
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6
Preparing the user program
For hard- and software installation of the CP340 you should follow the instructions given in the user
manual of the CP.
6.1
STEP7 HW-Config
After you have installed the CP340 into your system open the HW-Config and configure the
module accordingly and follow the steps below.
1. Place the correct version of your CP340 module into the HW-Config matching with the real
position of the module in your physical rack.
2. Note down the I-address of the module. That address will be required as LADDR input
parameter to the FB34 “MBMA340” Modbus Master Communication function block.
3. As protocol “ASCII” needs to be selected in order to adapt the Modbus RTU Master
protocol.
4. The protocol parameters need to match with the parameters at the connected Modbus Slave
devices.
5. Save, compile and download the hardware configuration to your CPU.
ASCII F. MODBUS RTU MASTER
LADDR
PROTOCOL PARAMETER
This picture shows an example configuration of a CP340.
MBMA340 Software driver for S7-300/400 controllers with serial communication processor module CP340 / Modbus RTU Protocol
Manual V2.00 English
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6.2
STEP7 Project program blocks
All the below following function blocks should be part of your software




FB10
FB2*
FB3*
FB34
“MBMAREQ”
“P_RCV”
“P_SEND”
“MBMA340”
Modbus Master Request function block
Siemens standard receive function block for CP340
Siemens standard send function block for CP340
Modbus Master Communication function block
* This function block is called internally from the “MBMA340” function block and its FB number
is not allowed to be changed. The programmer needs to ensure that the FB number is not occupied
by any another function block.
While the “MBMAREQ” function block can be called as many times as required in your
application the “MBMA340” function block is only allowed to be called one time per CP340
interface module in the user program. Independent on the number of Modbus Slaves attached to this
one interface.
The below diagram shows the typical sequence of the function blocks in the user program. Both
“MBMAREQ” and “MBMA340” call in cyclic executed OB1 or “MBMA340” called from cyclic
interrupted organization block (i.e. OB35). Find out more about its second option in chapter 8.
OB1
OB1
MBMAREQ
MBMAREQ
Request No. 1
Request No. 1
MBMAREQ
MBMAREQ
Request No. 2
Request No. 2
MBMAREQ
MBMAREQ
Request No. n
Request No. n
OB35
20ms
MBMA340
MBMA340
MBMA340 Software driver for S7-300/400 controllers with serial communication processor module CP340 / Modbus RTU Protocol
Manual V2.00 English
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These two function blocks are exchanging data through the LINK parameter on each of the blocks.
The programmer needs to ensure that the LINK parameters on the “MBMAREQ” blocks are
identical with the LINK parameter at the corresponding “MBMA340” communication function
block.
MBMAREQ
LINK
Request No. 1
LINK
MBMA340
MBMAREQ
Request No. 2
LINK
LINK parameters must be identical
See in the next chapter the use of configuring requests with the “MBMAREQ” function block and
showing the corresponding Modbus Function Code.
7
Supported Modbus Function Codes with program example
The following Modbus function codes are supported by this driver:
Function Code 01 - Read Coil Status
Function Code 02 - Read Input Status
Function Code 03 - Read Output Registers
Function Code 04 - Read Input Registers
Function Code 05 - Force Single Coil
Function Code 06 - Write Single Register
Function Code 15 - Force Multiple Coils
Function Code 16 - Write Multiple Registers
This software driver does use a “MBMAREQ” function block to configure all Modbus requests.
Pending on the information given at the input parameters during parameterization of the function
block it will automatically generate the corresponding Modbus function code internally.
The below given program code is just giving parameterization examples for the “MBMAREQ”
function block and might not reflect your application.
MBMA340 Software driver for S7-300/400 controllers with serial communication processor module CP340 / Modbus RTU Protocol
Manual V2.00 English
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7.1
Function Code 01 - Read Coil Status
CALL "MBMAREQ" , "MBMAREQ NO.1" // MODBUS MASTER REQUEST FUNCTION BLOCK
LINK
:=
"LINK_340"
// I-LINK WORD (CONNECT TO MBMA340 FUNCTION BLOCK!)
RW
:=
FALSE
// I-FUNCTION = READ
SLAVE
:=
1
// I-SLAVE NUMBER
START
:=
L#1
// I-START ADDRESS
(00001)
END
:=
L#9
// I-END ADDRESS
(00009)
WRMODE
:=
FALSE
// I-WRITE MODE = AUTO
S7ADDR
:=
"MBDB READ OUTPUTS STATUS".DATA_BYTE[0] // I-S7 ADDRESS
FORMAT
:=
1
// I-NONE
DONE
:=
"DONE_340"
// Q-DONE
ERROR
:=
"ERROR_340"
// Q-ERROR
STATUS
:=
"STATUS_340" // Q-STATUS WORD
7.2
Function Code 02 - Read Input Status
CALL "MBMAREQ" , "MBMAREQ NO.2" // MODBUS MASTER REQUEST FUNCTION BLOCK
LINK
:=
"LINK_340"
// I-LINK WORD (CONNECT TO MBMA340 FUNCTION BLOCK!)
RW
:=
FALSE
// I-FUNCTION = READ
SLAVE
:=
1
// I-SLAVE NUMBER
START
:=
L#10001
// I-START ADDRESS
(10001)
END
:=
L#10009
// I-END ADDRESS
(10009)
WRMODE
:=
FALSE
// I-WRITE MODE = AUTO
S7ADDR
:=
"MBDB READ INPUTS STATUS".DATA_BYTE[0] // I-S7 ADDRESS
FORMAT
:=
1
// I-NONE
DONE
:=
"DONE_340"
// Q-DONE
ERROR
:=
"ERROR_340"
// Q-ERROR
STATUS
:=
"STATUS_340" // Q-STATUS WORD
7.3
Function Code 03 - Read Output Registers
CALL "MBMAREQ" , "MBMAREQ NO.3" // MODBUS MASTER REQUEST FUNCTION BLOCK
LINK
:=
"LINK_340"
// I-LINK WORD (CONNECT TO MBMA340 FUNCTION BLOCK!)
RW
:=
FALSE
// I-FUNCTION = READ
SLAVE
:=
1
// I-SLAVE NUMBER
START
:=
L#40001
// I-START ADDRESS
(40001)
END
:=
L#40050
// I-END ADDRESS
(40002)
WRMODE
:=
FALSE
// I-WRITE MODE = AUTO
S7ADDR
:=
"MBDB READ OUTPUT REGS".DATA_BYTE[0] // I-S7 ADDRESS
FORMAT
:=
0
// I-NONE
DONE
:=
"DONE_340"
// Q-DONE
ERROR
:=
"ERROR_340"
// Q-ERROR
STATUS
:=
"STATUS_340" // Q-STATUS WORD
7.4
Function Code 04 - Read Input Registers
CALL "MBMAREQ" , "MBMAREQ NO.4" // MODBUS MASTER REQUEST FUNCTION BLOCK
LINK
:=
"LINK_340"
// I-LINK WORD (CONNECT TO MBMA340 FUNCTION BLOCK!)
RW
:=
FALSE
// I-FUNCTION = READ
SLAVE
:=
1
// I-SLAVE NUMBER
START
:=
L#30001
// I-START ADDRESS
(30001)
END
:=
L#30009
// I-END ADDRESS
(30009)
WRMODE
:=
FALSE
// I-WRITE MODE = AUTO
S7ADDR
:=
"MBDB READ INPUT REGS".DATA_BYTE[0] // I-S7 ADDRESS
FORMAT
:=
0
// I-NONE
DONE
:=
"DONE_340"
// Q-DONE
ERROR
:=
"ERROR_340"
// Q-ERROR
STATUS
:=
"STATUS_340" // Q-STATUS WORD
MBMA340 Software driver for S7-300/400 controllers with serial communication processor module CP340 / Modbus RTU Protocol
Manual V2.00 English
Page 12 of 15
7.5
Function Code 05 - Force Single Coil
CALL "MBMAREQ" , "MBMAREQ NO.5" // MODBUS MASTER REQUEST FUNCTION BLOCK
LINK
:=
"LINK_340"
// I-LINK WORD (CONNECT TO MBMA340 FUNCTION BLOCK!)
RW
:=
TRUE
// I-FUNCTION = WRITE
SLAVE
:=
1
// I-SLAVE NUMBER
START
:=
L#9
// I-START ADDRESS
(00009)
END
:=
L#9
// I-END ADDRESS
(00009)
WRMODE
:=
FALSE
// I-WRITE MODE = AUTO
S7ADDR
:=
"MBDB WRITE OUTPUT".DATA_BYTE[0] // I-S7 ADDRESS
FORMAT
:=
0
// I-NONE
DONE
:=
"DONE_340"
// Q-DONE
ERROR
:=
"ERROR_340"
// Q-ERROR
STATUS
:=
"STATUS_340" // Q-STATUS WORD
7.6
Function Code 06 - Write Single Register
CALL "MBMAREQ" , "MBMAREQ NO.6" // MODBUS MASTER REQUEST FUNCTION BLOCK
LINK
:=
"LINK_340"
// I-LINK WORD (CONNECT TO MBMA340 FUNCTION BLOCK!)
RW
:=
TRUE
// I-FUNCTION = WRITE
SLAVE
:=
1
// I-SLAVE NUMBER
START
:=
L#40003
// I-START ADDRESS
(40003)
END
:=
L#40003
// I-END ADDRESS
(40003)
WRMODE
:=
FALSE
// I-WRITE MODE = AUTO
S7ADDR
:=
"MBDB WRITE OUTPUT REG".DATA_BYTE[0] // I-S7 ADDRESS
FORMAT
:=
1
// I-NONE
DONE
:=
"DONE_340"
// Q-DONE
ERROR
:=
"ERROR_340"
// Q-ERROR
STATUS
:=
"STATUS_340" // Q-STATUS WORD
7.7
Function Code 15 - Force Multiple Coils
CALL "MBMAREQ" , "MBMAREQ NO.7" // MODBUS MASTER REQUEST FUNCTION BLOCK
LINK
:=
"LINK_340"
// I-LINK WORD (CONNECT TO MBMA340 FUNCTION BLOCK!)
RW
:=
TRUE
// I-FUNCTION = WRITE
SLAVE
:=
1
// I-SLAVE NUMBER
START
:=
L#1
// I-START ADDRESS
(00001)
END
:=
L#9
// I-END ADDRESS
(00009)
WRMODE
:=
FALSE
// I-WRITE MODE = AUTO
S7ADDR
:=
"MBDB WRITE OUTPUTS".DATA_BYTE[0] // I-S7 ADDRESS
FORMAT
:=
0
// I-NONE
DONE
:=
"DONE_340"
// Q-DONE
ERROR
:=
"ERROR_340"
// Q-ERROR
STATUS
:=
"STATUS_340" // Q-STATUS WORD
7.8
Function Code 16 - Write Multiple Registers
CALL "MBMAREQ" , "MBMAREQ NO.8" // MODBUS MASTER REQUEST FUNCTION BLOCK
LINK
:=
"LINK_340"
// I-LINK WORD (CONNECT TO MBMA340 FUNCTION BLOCK!)
RW
:=
TRUE
// I-FUNCTION = WRITE
SLAVE
:=
1
// I-SLAVE NUMBER
START
:=
L#40004
// I-START ADDRESS
(40004)
END
:=
L#40005
// I-END ADDRESS
(40005)
WRMODE
:=
FALSE
// I-WRITE MODE = AUTO
S7ADDR
:=
"MBDB WRITE OUTPUT REGS".DATA_BYTE[0] // I-S7 ADDRESS
FORMAT
:=
0
// I-NONE
DONE
:=
"DONE_340"
// Q-DONE
ERROR
:=
"ERROR_340"
// Q-ERROR
STATUS
:=
"STATUS_340" // Q-STATUS WORD
MBMA340 Software driver for S7-300/400 controllers with serial communication processor module CP340 / Modbus RTU Protocol
Manual V2.00 English
Page 13 of 15
8
Performance
Modbus is an asynchronous protocol where the Modbus Master is sending its requests one by one to
the connected slave. The Master is always waiting for the reply or timeout of the slave before
sending the next request.
So than more requests need to be executed than more time it will take to process them all. Therefore
it is advisable to reduce the total number of requests to a minimum to achieve a fast update cycle.
Unfortunate some vendors provide their data spread all over the Modbus address areas where and
make it necessary to define more requests. In case you have a PLC as a slave you might request the
supplier to provide the data in one compact area.
The standard Siemens “P_SEND” and “P_RECV” function blocks called internally from the
Modbus Master Function block can require several cycles to complete the data transfer between
CPU and CP module. First the user should leave the “MBMA340” Modbus Master Function block
in OB1 and monitor the cycle time of OB1. In case the OB1 cycle time is greater than 20ms the user
can move the “MBMA340” function block into an interrupt OB with a faster execution time (i.e.
OB35 >=20ms).
9
Trouble shooting
If you have done everything correctly you should be able to monitor at the CP340 that both, the TxLED and Rx-LED, are flashing from time to time and the requested data from the Modbus Slave is
stored into its destination address of the CPU. Unfortunate that’s not always the case but at least
you should have the Tx-LED flashing confirming that the Master is sending requests. Apart from
various hardware and wiring problems the programmer should verify the below points:
 In HW-Config of the CP340 the protocol is set to “ASCII”
 The ASCII protocol parameters at “Speed” and “Character Frame” should match with the
attached Modbus Slave devices
 FB2 “P_RCV” and FB3 “P_SEND” are existing and not changed to other FB numbers
 All function blocks are using individual instance data block numbers
 The LINK parameter at “MBMAREQ” is same as the corresponding “MBMA340” block
 The STATUS output at “MBMAREQ” is not showing any error code
 The LADDR input parameter at “MBMA340” is giving the correct hardware address of the
CP340 configured in HW-Config
MBMA340 Software driver for S7-300/400 controllers with serial communication processor module CP340 / Modbus RTU Protocol
Manual V2.00 English
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10 Service and Support
In case you face any problem with implementing the software into your application visit the
Siemens Simatic forum for latest information and updates.
https://www.automation.siemens.com/WW/forum
With Best Regards.
TIBI68
MBMA340 Software driver for S7-300/400 controllers with serial communication processor module CP340 / Modbus RTU Protocol
Manual V2.00 English
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