What's means by Overload on certain Device metric data ?? any advise to reduce Overload .
this device is Modbus TCP/IP.
If you look close at the 1000ms statistics, you have enough tags close enough together that Ignition can read your 843 tags with 20 optimized requests. However, your requests are each taking around 100ms (mean response time), with some taking around 200ms (from the histogram). So you can't possibly get all 20 requests processed in the desired 1000ms, and with any other activity (writes, direct OPC reads) also using time, you aren't even getting close.
Options:
-
Reduce response times (better device hardware, don't sample over a WAN). If true serial Modbus is on the other end, try increasing its baud rate.
-
Reduce number of tags. Or, reduce the number of tags that are polled quickly, and move less important tags to a slower tag group.
-
Possibly partition into two devices in Ignition pointing at the target device. One for high priority, the other for lesser priority.
3 Likes
The "Overload" is just the Actual Sampling Interval vs the requested sampling interval.
In your case, you've requested sampling @ 1000ms, but given the number of requests and the response time from the PLC/device, you're only achieving sampling every ~3000ms.
4 Likes