We have a S5 928B Processor, with an IM308B ET200 card. The profibus network has a 16I/16O ET200B IO module, an OP15, and a profibus Festo valve island.
The problem that we are seeing is that the inputs on the ET200B module - despite showing as constantly ON on the module LEDs - appear on a PG as zeros for most of the time, with an occasional flash of their actual values.
We have replaced the ET200B module, and its base. We have also removed the existing profibus cable from the ET200B module and IM308B. We put a test profibus cable between the IM308B and a replacement ET200B module with the same profibus address. A signal was put into one of the inputs of the replacement module, and when observed through the PG, that input displayed the same behaviour as previously seen. The input showed as a 0 with an occasional flash of its true value, a 1.
None of the other inputs on this profibus network (specifically from the Festo module) show this behaviour.
Rewiring the problem inputs into unused input cards on the main rack resolved the issue, insofar as we were able to get the machine running again, but the problem remains unresolved.
Any ideas what might be causing this please?
thanks,
Martin
The problem that we are seeing is that the inputs on the ET200B module - despite showing as constantly ON on the module LEDs - appear on a PG as zeros for most of the time, with an occasional flash of their actual values.
We have replaced the ET200B module, and its base. We have also removed the existing profibus cable from the ET200B module and IM308B. We put a test profibus cable between the IM308B and a replacement ET200B module with the same profibus address. A signal was put into one of the inputs of the replacement module, and when observed through the PG, that input displayed the same behaviour as previously seen. The input showed as a 0 with an occasional flash of its true value, a 1.
None of the other inputs on this profibus network (specifically from the Festo module) show this behaviour.
Rewiring the problem inputs into unused input cards on the main rack resolved the issue, insofar as we were able to get the machine running again, but the problem remains unresolved.
Any ideas what might be causing this please?
thanks,
Martin