SLC5 Slow Updates in Kepware

[Gforce3864]

I am having a weird experience using KepwareEx6 as an OPC Server for a set of SLC processors where the tag data is not updating remotely at the correct rate.

I have a KepwareEx6 server configured with 46 channels one SLC PLC per channel and roughly 160 tags per PLC configured in Kepware. The SLCs are connected to the network via DH+ I have two data highway devices with 23 devices each split between their two channels (12 per channel).

The tags have varying scan rates to try an optimize tags I need more often vs ones I don’t. The general scan rate I’ve used is 1000ms per tag on these devices. What I’m seeing though in most cases is that I won’t see a tag change in Kepware OPC Quick client for far far longer sometimes it takes 10-50s to see the tag change when I know the tag is changing every second.

If I’m monitoring the SLC's tag changes using RSlinx I can see it changing in nearly real time. I even have a custom logging service I use that makes use of an INGEAR driver and it doesn’t have any delays in tag scans on the SLC processors.

Has anyone had an issue like this before?

 

[Ken Moore]

So...DH+ is a token passing protocol, each CPU only communicates when it has the token, and it's serial communication. So...depending on HMIs, historians, messages, etc... I doubt 1000msec updates is doable with 13 devices per network.

 

[Gforce3864]

Why would RSLinx be able to read the tags at a low ms scan time whenever I use it to check? It has to go through the same route to the processor through the DH+ that Kepware is using.