Modbus OPC tag disconnecting constantly

jlam · September 18, 2019, 4:55pm

Hi,

I’ve been connecting to a Modbus device to gather data measurements and the data comes through from OPC tags for ~10 seconds (data is updating), but then it stops.

The logs show this message: ReadHoldingRegistersRequest , Request failed. FailureType==DISCONNECTED

I’ve been playing around with my tag groups and their common Rate (~10,000) and custom opcRate (~10,000). Should I be using both of these rates with the same value? I have been using two different values.

Is this the same case as (Modbus TCP Request Failed)? Could you direct me to the fixes that were mentioned here ([bug-14313]Direct Tag Group running on Leased/Driven rate)?

Detailed message below:
java.lang.Exception: RequestCycle stopped.
at com.inductiveautomation.xopc.driver.api.BasicRequestCycle.shutdown(BasicRequestCycle.java:281)
at com.inductiveautomation.xopc.driver.api.AbstractDriver.createNewRequestCycle(AbstractDriver.java:763)
at com.inductiveautomation.xopc.driver.api.AbstractDriver.notifyDisconnectDone(AbstractDriver.java:722)
at com.inductiveautomation.xopc.driver.api.AbstractIODelegatingDriver.notifyDisconnectDone(AbstractIODelegatingDriver.java:71)
at com.inductiveautomation.xopc.driver.api.AbstractIODelegatingDriver.disconnect(AbstractIODelegatingDriver.java:43)
at com.inductiveautomation.xopc.driver.api.AbstractIODelegatingDriver.reconnect(AbstractIODelegatingDriver.java:93)
at com.inductiveautomation.xopc.drivers.modbus2.AbstractModbusDriver.access$000(AbstractModbusDriver.java:97)
at com.inductiveautomation.xopc.drivers.modbus2.AbstractModbusDriver$2.notifyCommunicationTimeout(AbstractModbusDriver.java:138)
at com.inductiveautomation.xopc.drivers.modbus2.requests.AbstractModbusRequest.fail(AbstractModbusRequest.java:169)
at com.inductiveautomation.xopc.drivers.modbus2.requests.AbstractModbusReadRequest.fail(AbstractModbusReadRequest.java:121)
at com.inductiveautomation.xopc.driver.api.requests.TimedRequest.fail(TimedRequest.java:44)
at com.inductiveautomation.xopc.driver.api.BasicRequestCycle$TimeoutDaemon.failRequests(BasicRequestCycle.java:374)
at com.inductiveautomation.xopc.driver.api.BasicRequestCycle$TimeoutDaemon.run(BasicRequestCycle.java:329)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
at java.base/java.util.concurrent.FutureTask.runAndReset(Unknown Source)
at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.base/java.lang.Thread.run(Unknown Source)

WillMT10 · September 18, 2019, 5:00pm

Looks like this post may be a similar issue to what you’re seeing: modbus connection toggling between connected disconnected

jlam · September 26, 2019, 3:05pm

Hmm I tried changing the poll rates, having some tags with a 5s scan rate and the rest around 7s but still no luck. If I make the scan rate extremely small, it seems to just timeout faster (from 2min to 1min).

Looking at all of the log messages, is LegacyScripting[system_util_tag] relevant to the disconnection?

pturmel · September 26, 2019, 3:19pm

What loading is showing on the diagnostics page for that device?

Kevin.Herron · September 26, 2019, 3:20pm

There’s a setting on the Modbus driver called “Reconnect After Consecutive Timeouts”. Try disabling this.

jlam · September 26, 2019, 3:41pm

Sorry, I wasn’t sure if you meant the Execution or Threads page, so I’ve taken some screenshots of both, related to this device

jlam · September 26, 2019, 3:50pm

Now my device is connected, but the data does not come through once it has a timeout

Perhaps an unrelated question, but what is the differenc between the Common Rate and Custom OPCrate matter? Should they be the same? I’ve tried setting them <10s to avoid device inactivity