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Entry type: Application example Entry ID: 60735352, Entry date: 07/02/2019

Simatic S7-300/S7-400: Wizard for creating connection data for Modbus/TCP communication (Modbus/TCP Wizard )

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  • Associated product(s)
With a SIMATIC S7-300 / S7-400 CPU and an external CP 343-1 / CP 443-1 or a CPU with integrated PROFINET interface a communication to a third party device via Modbus/TCP can be realized.

The configuration of a Modbus/TCP communication is possible using additionally ordered blocks for Modbus/TCP communication.

  • SIMATIC Modbus/TCP CP: Article number 2XV9450-1MB00 and 6AV6676-6MB00-6AX0 and 6AV6676-6MB00-6AD0
  • SIMATIC Modbus/TCP PN CPU: Article number 2XV9450-1MB02, 6AV6676-6MB20-3AX0 and 6AV6676-6MB20-3AD0
  • SIMATIC Modbus/TCP CP Redundant: Article number: 6AV6676-6MB30-3AX0, 6AV6676-6MB30-3AD0, 6AV6676-6MB30-4AX0 and
  • SIMATIC Modbus/TCP PN CPU Redundant: Article number 6AV6676-6MB10-0AX0 and 6AV6676-6MB10-0AD0

The Modbus/TCP Wizard supports you in two duties:

  • Projecting the parameter data block
  • Licensing the Modbus/TCP blocks

Projecting the parameter data block
For easy configuration of this Modbus/TCP communication (TCP native) we offer you the Modbus/TCP Wizard as a free download. For the Modbus/TCP communication with the Modbus/TCP blocks the parameters for each connection have to be specified in a data block. Using the Modbus/TCP Wizard tool enables after selecting a product simple and clear specification of the connection parameters and Modbus parameters.
For a communication with an external CP 343-1 / CP 443-1 a configured TCP connection in NetPro is needed. For the communication via the PROFINET interface of the CPUs, the communication blocks FB65 "TCON", FB66 "TDISCON", FB63 "TSEND" and FB64 "TRCV" are used.
The tool then exports a DB with all parameters of the connection description into your STEP 7 project. Existing connections can be read, altered and copied.

Licensing the Modbus/TCP blocks
Using the Modbus/TCP Wizard to read the IDENT_CODE from the CPU online and show the IDENT_CODE as DataMatrix. The requested REG_KEY can be saved into the data block and can be loaded into the CPU. 

The following figure shows the start screen of the Modbus/TCP Wizard.

Figure 1


  • For the previous version SIMATIC Modbus/TCP Red V2 (Order number 2XV9450-1MB11) no wizard is used. The parameters are set to the block direktly.
  • The SIMATIC Modbus/TCP Wizard is an offline projecting assistent. The real transmission of telegrams is controlled at run time by the runtime parameters of the client

Documentation and Project
  Documentation (2,7 MB)
 Registrierung notwendig  SIMATIC Modbus/TCP Wizard (3,0 MB)

Further Information
More information for open communication via Modbus/TCP
Note for STEP 7 V5.5 SP3
It may occur rarely that the S7 station can not be displayed in the wizard, if STEP 7 V5.5 SP3 is used and an S5 station is existing in the same project. In this case the connection parameterization can be executed in a temporary project without S5 station and then the blocks are copied into the original project.

Last Changes
SIS-CPU 6ES7410-5FM08-0AB0 is supported 

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