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Entry type: Application example Entry ID: 21364749, Entry date: 09/12/2006
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Modem Connection between S7-300 Stations via serial CPs

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Task:  
A frequent task is to transfer small to medium size data volumes from one S7-300 station to another S7-300 station as simply and cost-effectively as possible. Communication of both controllers should run via a telephone system so that the distance between both stations plays a secondary role for the configuration. The controllers are connected to the telephone system via modems and serial CPs.

Solution:  
For solving the automation task, a modem connection is established between both stations. The modems are controlled by the S7-300 CPU via serial communiction groups CP 340 or CP 341.

This application uses the specially developed function blocks FB 100/FB 101, which after specifying some parameters dial into the remote partner station via a dialup network, and send data to or receive data from the partner station.

The pictorial schematic of this application is illustrated in the figure below:

Two configurable communication blocks were developed based on this principle. The FB 100 "Mod_CP340" is used for communication between CP 340 and modem, and FB 101 "Mod_CP341" for communication between CP 341 and modem. Using these blocks, a connection between both stations can be established and data can be exchanged (in this example in form of message texts).

The following figure shows the hardware setup of the application:

 

Downloads

Download contents

Download

Documentation (German) 
This document contains the application description: "Modem connection between S7-300 stationa via serial CPs"
21364749_CP34x_Modem_Kommunikation_DOKU_V11_d.pdf ( 584 KB )
Documentation (English) 
This document contains the application description: "Modem connection between S7-300 stationa via serial CPs"
21364749_CP34x_Modem_Kommunikation_DOKU_V11_e.pdf ( 579 KB )
Example project
This download contains the STEP 7 project of this application. After specifying some parameters, it is immediately runnable.
21364749_CP34x_Modem_Kommunikation_CODE_V11.zip ( 367 KB )
Block description (German)
This document contains a description of the function blocksFB 100 and FB 101 for modem communication.
FB_100_101_Mod_CP34x_LIB_V11_d.pdf ( 92 KB )
Block description (English)
This document contains a description of the function blocksFB 100 and FB 101 for modem communication.
FB_100_101_Mod_CP34x_LIB_V11_e.pdf ( 90 KB )
Block library (Germany)
This download contains a STEP 7 library with the communication blocks FB 100 / 101 and their instance DBs.
FB_100_101_Mod_CP34x_LIB_V11_d.zip ( 245 KB )
Block library (English)
This download contains a STEP 7 library with the communication blocks FB 100 / 101 and their instance DBs.
FB_100_101_Mod_CP34x_LIB_V11_e.zip ( 244 KB )

 

History

Issue

Changes

05/2005 First edition
08/2006 Standard software (FB2, FB3, FB7, FB8) updated
Return telegram added
Usage of  modems SINAUT MD3

 

Keywords:
CP 340, CP 341, Modem communication, FB 100 "Mod_CP340", FB 101 "Mod_CP341", ISDN, analog, dialup connection, serial communication