1. Home
  2. ⧑ Industrial Control Group
  3. FIP IO BUS WITH RANDOM ERRORS

FIP IO BUS WITH RANDOM ERRORS

Hi I have just comissioned my first distributed control system using a Premium PLC and 18 Momentum I/O bases, connected with a FIP IO field bus 200 meters long. Wiring has been carried out with full EMC and Schneider's specs. It works OK, but now and then the bus starts to fail at an increasing rate and suddenly, starts to work OK again. It works OK for several days, and then it fails again. I have tried everything for trouble shooting it, with no positive results. The only thing I think is affecting the bus is ambient temperature. I have observed that failures occur in cold days, say below 6 ºC. Is it possible?

Many thanks

Lorenzo

Reply to
Lorenzo Hill
Loading thread data ...

Lorenzo,

Is it possible your connections are suffering from shorts due to condensation? In general, there is no direct temperature affect that should impact your communications. I have experience down to -60 °C and the only difference is a reduction in voltage drop. Is your wiring running parallel to any power cables that might be related to temperature or time of day such as electric heaters? It is difficult to trouble shoot intermittent faults without a lot of information.

By-the-way, your control system may be distributed but that does not make it a Distributed Control System (DCS). What you have is a PLC with remote I/O.

Walter.

Reply to
Walter Driedger

I can't think of any low temperature faults except condensation. Batteries are weaker at lower temperatures, but 6 °C is hardly low. I doubt very much that your CPU suffers at that temperature. It should probably become MORE reliable.

I haven't the slightest idea what particular information to ask for. It's a holistic thing. Describe the entire environment in which the equipment is found. Describe your shielding and grounding.

Walter.

Reply to
Walter Driedger

I have had similar problems have you an approximate time or times when this occurs

Mike

Reply to
Mike Spear

Dear friends

Finally the fault was in the premium cpu. We got another one to replace it and the errors counters stopped clicking!!!!!

What a relief

Many thanks to everyone

Lorenzo

Reply to
Lorenzo Hill

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.