Combine Hima and Siemens on RS485

  • Thread starter Steven Batselier
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Thread Starter

Steven Batselier

I want to add 2 Siemens S7-300 slaves to an existing Hima network (with Honeywell EPLCG as PLC/TDC-master)

But when I connect the Siemens, my CRCs become bad and the Siemens slaves have serious com problems. Sometimes one becomes ok, but not long.

Has anyone experienced this before? Are there solutions to connect these slaves on RS485-level?

That infers that the comm link is set up OK - baud rate, parity, etc. and that for some short period of time comm can be established and data transferred.

If comm then fails by CRC check, it is likely a noise issue on the signal lines. Look at the cabling, shielding and grounding, possibly the location/absence/presence of the termination resistor.