Kepware not Reading Values from Modbus TCP/IP Driver


Thread Starter

Osman Ahmad

I am running into a strange issue where I have 30 channels with one device per channel configured in KepserverEX. These include 3 Omni channels, 1 Triconex and rest 26 are Modbus TCP/IP device channels. The Triconex Channel has over 20,000 tags and is the biggest channel-device configured in terms of volume of tags. Also one of the Modbus device channel is configured for 12000 tags. All of the devices including these two channels are fetching data very smoothly and are updated well-within time. The scan rates vary from 1-3 secs.

However we are facing an issue where we are getting very much delay in receiving data from one of the Modbus Devices which has only 10000 tags. The settings in Kepware other than the scan rate have been kept the same for all devices but the delay in getting data is problematic for only one of the particular Modbus devices having tags of around 10000 which is very less than Triconex Device which have 2-3 times the number of tags and another Modbus device having tags greater than this one.

Any possible way-around or diagnosis to verify if this is an issue from the PLC end? What can be done to improve the data update rate in Kepware.
if the problem is from PLC end, to speed-up the modbus scan rate: try to arrange the modbus registers in sequence i.e: there is no gaps between them. to allow the master to acquire them in multiple registers format