OPTO22 Groov Epic PR2 Modbus Comms Dropping out every 2 hours and 4 Mins

Hi after some assistance with an error on a Groov PR2 PLC.

We have a few different communications set up as shown below:

  • One Modbus TCP Slave Connection - ( Sending / Receiving Data from a PC )
  • Two Modbus TCP Master Connection - ( Reading Data from a UPS Panel and Reading Data Gas Chromatograph)
  • One Modbus RTU Slave Connection 485 - (Reading Data from a fire and gas panel)
  • One Modbus RTU Master Connection 485 - (Sending Data to a Telemetry Unit)

All Licenses have been installed as per OPTO22 suggestions of the order below:

  • Modbus TCP Master
  • Modbus TCP Slave
  • Modbus RTU Master
  • Modbus RTU Slave

When I check on License manager the RTU Master license seems to disappear on installing the RTU. (What ever reason I’ve been told this is “normal”). If I use Device License Read It will successfully read all the licenses correctly.

Now the issue is every 2 hours and between 4. For what ever reason the communications seems to end and lock up for about 20 seconds. During this time even if I was logged into the PLC it would kick me off and I’d have to re type the password to enter.

Most of the devices can handle this however the RTU flags up a communications failure at the SCADA and is raising alarms every 2 hours and 4 mins. We’ve had multiple people go through the code to check for anything obvious. Does anyone have any ideas?

Greetings and welcome to the Opto22 forums!

We might need a little more information to help here…
The modbus charts in PAC Control don’t have any licenses attached, so I wonder if you are using Ignition EDGE?
Ignition does have a 2 hour trial mode and it will time out and need to be restarted to keep running.

The fact that you said you get logged out of the EPIC also sounds a bit odd.
I wonder if you are using groov View to display the data? It also has a 2 hour trial mode, but it will not log you out, but rather yellow triangles will show up on the screen and when you click on them it will state that the trail mode has expired.

Can you break down a bit more what software packages you are using the Modbus in?

This sounds like a licensing issue with Codesys. I have not heard that it is normal to not see a license in the License Manager, and the fact that it is timing out every 2 hours sounds like the license is not installed correctly. Can you email me the information regarding this unit and license, so I can get it to Codesys to remedy. You can email me directly at greichert@opto22.com

The Modbus licences you are referring to are for CODESYS I believe.

Has CODESYS licence been activated in this GRV-EPIC-PR2?

If not, I think this may be causing the issues you are experiencing.