Citect Modicon Quantum Communications

Hi, I am using Citect (redundant Servers) and Modicon Quantum (Hotstandby) and using NOE ethernet module for communication. THe updation speeds at CITECT is very slow and i also get errors in communication. Has anyone faced this before and if so is there a fix for this problem.....

Thanks in Advance
P Ganasa

I had a customer with a very simular application, but was using InduSoft WebStudio as the SCADA instead of CiTect. It ended up being a bad NOE module in the end, but had alarms and bad data from time to time. CiTect has really good drivers I've been told, so I don't know if it would be a driver issue. The only other problem I've seen with Quantium hotstandby and HMIs is the fact that Modicon does an IP address swap for the hotstandby processors. I've seen panels (not PCs) talking to hotstandby processors actually not reconnect to the new "master" processor after an IP swap, it turned out that the driver used on the panels was tied to the MAC id of the processor and not the IP address. Hope you might find this info useful. The bad NOE module was hard to find, the first reaction was to point fingers at the software guys.

My former employer was one of the first to use this setup, although we didn't use hot standby.
We had exactly the same problem, and it was tracked down to the Citect driver. This was on Citect V5.0. The problem was fixed by Citect in a short period of time and since then it ran perfectly.

In your case, I would check the Citect knowledge base for this problem (available at www.citect.com).
Also, check the Citect help file under Modicon/Modbus. Many PLCs have some setup tricks (I can't remember those for Modicon off the top of my head).

The previous responder's idea of a bad NOE is also worth checking.
Also, problems with the cabling caused me similar problems with a Siemens S7 communicating with Citect.
Finally, I think that Citect reads the IP address, not MAC address.

Hope this helps,

Doug

Hi
My earlier post was a bit breif, i found that the SCADA updation depends on Hotstandy being online, when the Hot standby goes offline, the updation at the SCADA is satisfactory (Almost 100% improvement). I had conducted some further tests and all fingers point to the fact that the Qunatum CPU may not be responding to CITECT's request. The NOE modules contain the latest firmware as is the CPU. I do not suspect that the NOE module has conked off.....
Will update as soon as i get a fix or some one who faced this before drop me a line

Best Regards

Hi Doug,
Forgot to add that i adjusted the default parameters of the Modnet driver. I will not say i got mucha difference..