105BCommunication processor
12.5 Modbus communication
S7-1200 Programmable controller
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System Manual, 11/2011, A5E02486680-05
12.5.2.6
MB_CLIENT example 3: Output image write request
This example shows a Modbus client request to write the S7-1200 output image.
Network 1: Modbus function 15 - Write S7-1200 output image bits
12.5.2.7
MB_CLIENT example 4: Coordinating multiple requests
You must ensure that each individual Modbus TCP request finishes execution. This
coordination must be provided by your program. The example below shows how the outputs
of the first and second client requests can be used to coordinate execution.
The example shows both clients writing to the same memory area. Also, a returned error is
captured which is optional.
Network 1: Modbus function 3 - Read holding register words