What are the options for accessing an S7-200 with WinCC?
The following options are available for communication between WinCC and an S7-200.
- Communication via OPC
S7-200 PC Access
With the OPC server of S7-200 PC Access you can set up communication between the S7-200 and WinCC via OPC. When implementing the S7-200 OPC server it is of advantage to integrate the symbols of the STEP 7 Micro/WIN project. The S7-200 PC Access OPC server can be linked with the S7-200 via the following types of connection:
- PPI via PC/PPI cable
- USB/PPI cable (article number: 6ES7 901-3DB30-0XA0)
- RS232/PPI cable (article number: 6ES7 901-3CB30-0XA0)
- RS232/PPI cable (article number: 6ES7 901-3BF21-0XA0)
- MPI and PROFIBUS via PROFIBUS CPs
- CP5611, CP5511, CP5512
- External and internal modems and the modem module S7-241
- Ethernet for Local Area Networks (LANs) and Wide Area Networks (WANs) via CP243-1 or CP243-1 IT.
With the S7-200 PC Access OPC server data can be read simultaneously from up to eight S7-200 target systems.
More information about the S7-200 OPC server is available in the S7-200 PC Access Online Help in Entry ID: 19301654.
SIMATIC NET OPC Server
In addition you can set up the connection via the OPC server of SIMATIC NET. Which version of SIMATIC WinCC is released for which version of SIMATIC NET and which version of SIMATIC NET is supplied with SIMATIC WinCC is described in Entry ID: 64847781
For this connection you need an S7-2xx module, firmware version 1.22 or higher. A detailed description of Ethernet communication between an S7-200 and WinCC as well as a relevant example are available in Entry ID: 14587200.
- Communication via "Modbus Serial"
Via the "Modbus Serial" channel you can use the PC/PPI cable to directly access the inputs, outputs and tag words of the S7-200 CPU. You can also address multiple CPUs. The only requirement is that the CPUs are connected together via PROFIBUS DP. For this the command library for the Modbus protocol must be loaded into the CPU.
The "Modbus Serial" channel is not included in the basic package of WinCC. You can procure this channel from the engineering consultants Ingenieurbüro Allmendinger (www.allmendinger.de).
- Communication via "Modbus Serial Modem"
You can establish a connection between your WinCC station and the S7-200 via a telephone line using the "MODBUS Serial Modem" channel. You can access inputs, outputs and tag words. For this you need the S7-200 communication module EM241. This module facilitates special communication requirements, like remote maintenance, telecontrol, signaling or remote data transmission over wide distances. The one drawback that should be mentioned is that connecting and disconnecting by dialing using the modem is slow.
The "Modbus Serial Modem" channel is not included in the basic package of WinCC. You can procure this channel from the engineering consultants Ingenieurbüro Allmendinger (www.allmendinger.de).
- Communication via PROFIBUS DP
The connection via PROFIBUS DP is a fast form of communication, however it can only be used to control the inputs and outputs of the S7-200. In order to communicate via PROFIBUS DP, you require the S7-200 communication module, the EM277. How to set up a connection to an S7-200 via PROFIBUS DP is described in detail in Entry ID 21915525.