Instruction help!!

Hi,

I am using a AB Micrologix 1500 linked too a computer using RS232 and some OPC software.

We keep having problems where the communications drop out and were wondering is there is a system bit/instruction we could use so when it happens we could write a small bit of code so a message is displayed on the panel view too warn them.

Any help would be great!

Thanks

Are you using a USB/232 converter, if you are this is most likely the problem, as some work then stop communicating then work again. Try another converter instead of writing a fail com code.

Thank you for the reply!! yes your right we are using a converter, only because originally we were connected direct into the com port on the PC but for some reason that stopped working and will not re-connect so we changed too a converter and that did the same so we change too a new converter and so far it has been fine but until we can resolve the problem we need some sort of message or alarm to notify the operator of a com fail. The only system/status bit we have found are s:1/7 and s:33/4 both seem to relate too active comms, and trying too find some more information.

It would be best to have your PC setup some kind of hand shaking bit with the PLC. Basically have the PC continuously set the bit and have the PLC turn the bit off ever 5 seconds, and if it stays off for 10 or 15 seconds alarm that on your PanelView.