Siemens SIMATIC S7 User manual

SIMATIC
S7 - OPEN MODBUS / TCP
Communication via CP343-1 and CP443-1
Manual

SIMATIC S7
OPEN MODBUS / TCP
Communication via
CP343-1 and 443-1
Manual
Edition 4.3
Preface, Table of Contents
Product Description 1
Getting Started 2
Commissioning 3
Licensing 4
FB MODBUSCP 5
Diagnostics 6
Application Samples 7
Appendices
Literature
Glossary

Safety Precautions and
Warnings
This manual contains warnings, which you should note for your own safety as well as for
the prevention of damage to property. These warnings are indicated by means of a triangle
and displayed as follows in accordance with the level of danger:
__________________________________________________________________
Danger
indicates that loss of life, severe personal injury or substantial damage
will result if proper precautions are not taken.
__________________________________________________________________
__________________________________________________________________
Warning
indicates that loss of life, severe personal injury or substantial damage can result if proper
precautions are not taken.
__________________________________________________________________
__________________________________________________________________
Caution
indicates that minor personal injury or property damage can result if proper precautions are
not taken.
__________________________________________________________________
__________________________________________________________________
Note
call attention to information that is especially significant to the product, handling of the
product or a specific part of this documentation.
__________________________________________________________________
Qualified
Personnel The equipment may be commissioned and put into operation by qualified personnel only.
For the purpose of safety relevant warnings of this manual a qualified person is one who is
authorized to commission, ground and tag devices, systems and circuits.
Use as prescribed
Trademarks
Please note the following:
___________________________________________________________________
Warning
This equipment must only be used in applications as prescribed in the catalogue and the
technical description and in conjunction with equipment and components recommended and
authorized by Siemens.
Successful and safe operation of this equipment is dependent upon proper transport, and
storage, erection and installation as well as careful operation and maintenance.
SIMATIC®and SIMATIC NET®are registered trademarks of SIEMENS AG.
The other brand names in this manual may be trademarks use of which by third parties for
their purposes may infringe the proprietors’ rights.
Copyright ©Siemens AG 2004-2009 All Rights Reserved
The reproduction, transmission or use of this document or its contents
is not permitted without express written authority. Offenders will be
liable for damages. All rights, including rights created by patent grant
or registration of a utility model or design, are reserved.
Siemens AG
Industry Sector
Engineering and Construction
I IS IN E&C
P.O. Box 3240, D- 91050 Erlangen
[email protected]
Exclusion from Liability
We have checked the contents of this document with regard to
conformity to the described hardware and software. Deviations,
however, cannot be excluded; therefore we cannot accept prejudice
for its complete conformity. The information in this document is
checked regularly and necessary corrections are contained in
subsequent issues. Any suggestions for improvement are gratefully
received.
We reserve the right to make technical changes.

Preface
OPEN MODBUS / TCP communication via CP343-1 and 443-1
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Preface
Purpose of the
Manual The information in this manual allows you to set up and put in operation the
connection between the CP 343-1/CP 443-1 and a device that supports the
Open MODBUS/TCP protocol.
Contents of the
Manual This manual describes the function of the function block MODBUSCP and
its integration into the hardware and software of the communication
processors CP 343-1/CP 443-1.
The manual contains the following topics:
•Production description / Mounting
•Getting Started
•Commissioning
•Parameterization
•Licensing
•Function block MODBUSCP
•Diagnostics
•Application samples
Scope of this
Manual This manual is valid for the following software:
Product Identification number From version
OPEN MODBUS / TCP 2XV9 450-1MB00 4.3
FB 108 “MODBUSCP” 1.3 / 2.2
FB 106 “MB_CPCLI” 1.2 / 2.2
FB 107 “MB_CPSRV” 1.2 / 2.1
Note
This manual contains the FB description, as it is valid at the time of
publication.
How to Access the
Information in this
Manual
To enable you a quick access to selected information, the manual provides
the following access aids:
•The next pages contain a complete table of contents.

Preface
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Additional
Sources of
Information
All additional information concerning CP 343/CP 443 (mounting,
commissioning etc.) can be found in the manual
SIEMENS
SIMATIC NET
S7-CPs for Industrial Ethernet
device manual C79000-G8900-C155
SIEMENS
SIMATIC NET
S7-CPs for Industrial Ethernet
device manual part B1
CP 343-1 / CP 343-1EX20
C79000-G8900-C158
SIEMENS
SIMATIC NET
S7-CPs for Industrial Ethernet
device manual part B4
CP 443-1
C79000-G8900-C152
SIEMENS
SIMATIC NET
NCM S7 for Industrial Ethernet
manual C79000-G8900-C129
Additional information concerning STEP7 can be found in the following
manuals:
SIEMENS
SIMATIC Software
Base software for S7 and M7
STEP7 user manual
C79000-G7000-C502-..
SIEMENS
SIMATIC Software
System software for S7-300/400
System and standard functions
Reference manual C79000-G7000-C503-02
Additional
Questions If you have further questions regarding the use of the FBs described in this
manual, which are not answered in this document, please contact your
Siemens partner who supplied you with this function block.
Terminology This document uses the term CP or CP 343/CP 443. The descriptions only
apply to communications processor CP 343-1/CP 443-1.
Scope of
Application The function block described in this manual establishes a connection
between the CP 343-1/CP 443-1 and third party MODBUS devices.

Table of contents
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Table of Contents
1...... Product Description.......................................................................................................1-1
1.1........ Field of Applications..........................................................................................1-1
1.2........ Hardware and Software Prerequisites..............................................................1-2
2...... Getting Started...............................................................................................................2-1
3...... Commissioning ..............................................................................................................3-1
3.1........ Installing the Library on the STEP7 PG/-PC ....................................................3-1
3.2........ Parameterization of the CP ..............................................................................3-2
3.3........ Network Configuration......................................................................................3-4
3.4........ How to Select the Appropriate Modbus Block..................................................3-9
3.5........ Insertion of the Function Blocks into the Program..........................................3-10
3.6........ Multiple Connections via Port 502..................................................................3-12
3.7........ Start_up Characteristics of CP343 / CP443...................................................3-13
3.8........ Changeover of a Previous Version to V4.x ....................................................3-14
4...... Licensing ........................................................................................................................4-1
5...... Function Block MODBUSCP.........................................................................................5-1
5.1........ Functionality of the FB......................................................................................5-1
5.2........ Parameters of the Function Block MODBUSCP ..............................................5-4
5.3........ Address Mapping............................................................................................5-12
5.4........ Data and Standard Functions used by the FB ...............................................5-15
5.5........ Renaming of Standard Functions...................................................................5-17
6...... Diagnostics.....................................................................................................................6-1
6.1........ Diagnostics via the Display Elements of the CP ..............................................6-1
6.2........ Diagnostic Messages of the FB MODBUSCP..................................................6-2
6.3........ Diagnostic Messages of FC5/FC6 and FC50/FC60.........................................6-8
6.4........ Diagnostic Messages of included FCs/SFCs...................................................6-8
6.5........ Diagnostic Messages of SFC24.......................................................................6-8
7...... Application Samples......................................................................................................7-1

Table of contents
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7.1........ Sample project STL..........................................................................................7-2
7.2........ Sample project CFC .........................................................................................7-3

Product description
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1 Product Description
1.1 Field of Applications
Placement in the
System Environ-
ment
The driver described here is a software product for the Communications
Processor CP343-1/CP443-1.
The CP343-1 can be used in the SIMATIC S7-300 automation system and
can establish communication links to partner systems.
CP443-1 can be used in the SIMATIC S7-400 automation systems and can
establish communication links to partner systems.
Function of the
FBs These function blocks enable a communication link between CP343-1 /
CP443-1 and a device that supports the Open MODBUS/TCP protocol. The
function codes 1, 2, 3, 4, 5, 6, 15 and 16 are provided.
Data transmission is carried out following the Client-Server principle.
The SIMATIC S7 can act as both client and server during the data
transmission.
TCP/IP with
CP343-1 / CP443-1 TCP/IP with CP343-1 and CP434-1 uses static connections. The TCP
connection is not disconnected during errror-free operation.
Network configuration of STEP7 enables only a unique use of a specific
port number,when using TCP native stack of the CP.
However, with specific CP modules it is possible to use multiple connection
via port 502 to different clients simultaneously.
In section 3.6 “Mulitple connections via port 502” you can find technical details
regarding this matter.

Product description
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1.2 Hardware and Software Prerequisites
Usable Modules You can find the latest hardware prerequisites on the internet:
www.siemens.com/s7modbus.
Software Versions The usage of the modbus blocks is possible with STEP7 Version 5.4 or
higher. Withal the use of the blocks AG_LSEND/AG_LRECV V3.1 of the
update of SIMATIC NET library
(http://support.automation.siemens.com/WW/view/en/22172239) is required.
Memory
requirements The FB MODBUSCP requires ca. 6k byte work and load memory.
The FB MB_CPCLI requires ca.10k byte work and memory.
The FB MB_CPSRV requires ca. 10 k byte work and load memory.
The particular length of the blocks can be determined in the properties of the
block in the Simatic Manager.

Getting started
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2 Getting Started
Procedure 1. Install “OpenModbusTCP CP“.
=> Section 3.1
2. Parameterize the connection parameters regarding your requirements
(IP-address, port number, etc.).
=> Section 3.2 to 3.4
3. Insert the Modbus function blocks into your SIMATIC project.
=> Section 3.6
4. Call the Modbus block FB108 in the required OBs.
=> Section 5.1
5. Parameterize the Modbus block for initialization (client/server, DB areas,
Modbus addresses) and runtime.
=> Section 5.2
6. Load the user program into the PLC and license the Modbus block for this
CPU.
=> Section 4

Commissioning
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3 Commissioning
General
Information The configuration of the CP443-1/CP343-1 is possible via MPI or
LAN/Industrial Ethernet.
STEP7 is required with NCM S7 for Industrial Ethernet (shortly named
”NCM IE”).
The information below about STEP7 and the communication link configuration
refers to STEP7 Version 5.1 and NCM S7 Industrial Ethernet Version 5.1.
In later versions, the sequences, names and directories might be different.
Requirements Knowledge of AWL and basic knowledge of STEP7 and PLC.
3.1 Installing the Library on the STEP7 PG/-PC
What We Provide
You The attached CD contains a setup, which installs the library
“Modbus_TCP_CP”, 2 example projects and the manuals in English and
German in the corresponding STEP7 directories.
The manuals are available outside the setup additionally, to give you the
opportunity to get all information regarding the software without installation.
Requirements To install, STEP7 must be installed. With older STEP7 versions the option
NCM S7 for Industrial Ethernet is necessary additionally.
Installation Insert your Modbus CD into the CD-ROM drive and follow step-by-step the
instructions that are automatically displayed by the installation program. If the
installation program fails to automatically run, perform these steps:
1. Using Windows Explorer, navigate to the CD-ROM drive and go to the
directory setup and double-click Setup.exe file to start the installation
procedure.
2. Follow step-by-step the instructions that are displayed by the installation
program.
Now you can find
•the library in \Program Files\Siemens\Step7\S7libs,
•2 example projects in \Program Files\Siemens\Step7\Examples,
•the manual in \Program Files\Siemens\Step7\S7manual\S7Comm,
•the software registration form in
\Program Files\Siemens\Step7\S7libs\Modbus_TCP_CP.
To access the Modbus library the first time, use the browse function of the
open dialog for libraries.
The manual can be accessed via short cut in \Program Files \Siemens
\Documentation as well.

Commissioning
3.2 Parameterization of the CP
Parameterization
of the CP
If you have your stations connected with each other without a router, then
they have to be within the same subnet.
In the field Subnet connect the CP with the Industrial Ethernet. In order to do
that, select the entry with the name of your network. For newly created
networks this is normally “Ethernet(1)“.
Save and Compile the parameterization.
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Parameterization
of the
Communication
Partner
In the mode “CP is client” an “other station” is required for network
configuration.
After you have inserted the communication partner’s station into your STEP7
project (as described in “Project components: Insert ¾Other station“) you
have to specify the object properties of the external station.
1) Properties – Other Station ¾Interfaces
On the tab “Interfaces“ click on “New“. In the upcoming selection, select
“Industrial Ethernet” and click on “OK”.
This opens a dialog box “Properties – Ethernet Interface“. Enter an IP
Address that is in the same subnet as the communication partner’s station.
The subnet mask should be the same as the one of the partner’s station.
Select the associated subnet that connects the CP interface with the
communication partner’s interface.
Click on the “OK“ button. This will bring you back to the tab “Interfaces“.
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2) Properties – Other Station¾General
In tab “General” you do not have to make any settings.
3.3 Network Configuration
Communications
Connection The CP is the link for the Industrial Ethernet connection between the S7-CPU
and the communication partner / bus. A connection configuration must be
made for the connection of the interfaces to the communication partner / bus.
Configure Network
in mode “CP is
Client”
In the STEP7 project, select the CPU in your S7 300/S7 400-Station and open
“Network configuration“ by double clicking “Connections”. This opens the
program “NetPro“ with which your connections can be configured.
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After selecting Insert¾New Connection... the dialog box ”Insert new
connection“ will come up.
Select the connection partner (Other Station) for the new connection and use
“TCP Connection” for the connection. Put a check mark on “Show properties
dialog“
Click “OK“. This will take you back to the dialog box “Properties TCP
connection“.
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Object Properties
of the Connection •An ID is provided. You can change the ID if needed.
•Click on the button “Routing” and the configured connection will be shown.
•The MODBUS client must execute “Active connection establishment”.
•In the register “Addresses” the port numbers are defined.
Click on “OK“ and the inputs are accepted.
Save the network configuration and close the program “NetPro“.
Please note that the connection ID (Local ID) has to be used when the FB is
called in the user program.
Selection of the
Port Number In a MODBUS communication a MODBUS server are normally addressed via
port 502, whereas a MODBUS client uses a port from 2000.
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Unspecified
Connection with
“CP is server”
If you have got a communication with CP as MODBUS server, the
communication is set up as “unspecified connection”. The client must carry
out active connection establishment.
After selecting Insert¾New Connection... the dialog box ”Insert new
connection“ will come up.
Select here “unspecified” instead of the communication partner and use
“TCP Connection” for the connection. Put a check mark on “Show properties
dialog“
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Click “OK“. This will take you back to the dialog box “Properties TCP
connection“.
The check box “active connection establishment” must not be activated.
In the register “addresses” all information regarding the partner, “IP” and
“PORT” are left blank.
Click on “OK“ and the inputs are accepted.
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3.4 How to Select the Appropriate Modbus Block
General
Information The block FC10 AG_CNTRL of the SIMATIC_NET library permits to terminate
and reestablish an established connection. This block was also implemented
in the Modbus blocks for a more effective use of the resources of CPU and
CP. However, previous CPs or previous firmware releases do not support the
use of AG_CNTRL.
Therefore the library contains directories for both alternatives, each for
S7-300 CPs and S7-400 CPs:
•Current CP 300 CPs of S7-300 which support AG_CNTRL
(not for CPU315 and 317 HW release V1)
•Current CP 400 CPs of S7-400 which support AG_CNTRL
•Previous CP 300 CPs of S7-300 which do not support
AG_CNTRL
•Previous CP 400 CPs of S7-400 which do not support
AG_CNTRL
Pay attention to the count of local data of the used CPU! The required
local data for both alternatives are written in chapter 5.4.
Which CPs
support
AG_CNTRL?
Here you can find up-to-date information which CPs and which firmware
releases support AG_CNTRL:
Ethernet CPs and AG_CNTRL
If the used CP is not mentioned here, the Modbus blocks without AG_CNTRL
must be used.
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3.5 Insertion of the Function Blocks into the Program
Content of
MODBUS library The following blocks are required for the Modbus communication:
•MODBUSCP
•MB_CPCLI
•MB_CPSRV
Insertion of the
MODBUS FBs In order to exchange data with MODBUS devices, you need the function
blocks MODBUSCP, MB_CPCLI, MB_CPSRV and AG_CNTRL if applicable.
To be able to insert this into your project you have to copy the function block
from the library. For that, open the library “Modbus_TCP_CP“ by selecting
the menu item File ¾Open.
In the dialog box “Open Project“ select the tab ”Libraries“. Select the library
“Modbus_TCP_CP” using the Browse-Button and click “OK”.
This opens the library. Open the folder “CP 300” or “CP 400” according to
your Configuration by double clicking it. Select the function blocks and copy it
via “Edit ¾Copy”. Then change back to your project .
In the Step7 project, in your opened S7 300/S7 400-Station, select the CPU.
Double click “S7-program”, and then “Blocks”.
This will open the “Blocks” folder.
Select “Edit ¾Paste”. This will insert the block into your program.
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