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Siemens AG
Entry type: FAQ Entry ID: 12378422, Entry date: 08/31/2005

Why can't you communicate with SCADA software (WinCC) using SIMATIC MicroComputing V1.0 and the EM241 modem module?

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MicroComputing V1.0 does not support modem communication. However, S7-200 and WinCC do support the MODBUS protocol.

SIMATIC MicroComputing offers access to the process data in the S7-200 CPU and establishes the connection via ActiveX controls.

The EM241 modem module offers the "Remote communication" function for the S7-200 micro PLC and supports the following four operating mode:

  • Micro/Win connection for remote programming and trouble-shooting,
  • MODBUS master/slave communication,
  • alphanumerical messages and number call service,
  • as well as CPU-CPU communication between S7-200 micro-controllers.

For further information, please refer to the FAQs on "Possible ways of communicating with an S7-200 from WinCC V5.1", which you can find on the Internet under Entry ID: 21382197.

The HMI ‘WinCC’ software can be used as a MODBUS master and the EM241 modem module can be used as a MODBUS slave. Communication can be established this way between WinCC and the S7-22x CPU module via a telephone line.

Data transfer, Microcomputing, WinCC, Modem, S7-200

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