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Entry type: FAQ Entry ID: 103709633, Entry date: 07/20/2016

When compiling a CFC chart, why is the error message "Time stamp conflict" displayed in connection with the Modbus/TCP FBs for S7-400 CPUs?

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The NCM library and the PCS 7 library use different time stamps for the blocks FC50 'AG_LSEND' V3.1 and FC60 'AG_LRECV' V3.1.

Therefore, when compiling a CFC chart containing Modbus/TCP function blocks of the "SIMATIC Modbus/TCP CP" or "SIMATIC Modbus/TCP CP Red" library, time stamp conflicts might occur.

In case of a time stamp conflict, change the wiring of the blocks FC50 and FC60 to another number according to the Modbus/TCP manual. The rewiring updates the time stamp and the conflict is cleared.
Then you can change the wiring of the blocks back again to their original number.

Alternatively you can use the block FC50 and FC60 from the Modbus/TCP sample project.

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