# OPC Monitored Items

**URL:** <https://forum.inductiveautomation.com/t/opc-monitored-items/109003>\
**Category:** Ignition\
**Tags:** opcua, vision, ignition81\
**Created:** [July 28, 2025, 12:46pm UTC](https://forum.inductiveautomation.com/t/opc-monitored-items/109003 "2025-07-28T12:46:56Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [July 28, 2025, 1:05pm UTC](https://forum.inductiveautomation.com/t/opc-monitored-items/109003/2 "2025-07-28T13:05:47Z")

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I would suspect a session timeout on the Omron side was still holding the items from before the restart, and therefore rejected the post-restart subscription requests. Which were then poked/prodded when you added the one item a bit later.

Vendors put limits in these on-PLC OPC servers to protect the device against overload (OPC servers are pretty heavy-weight tasks for true real time environments), but those limits have side effects. If you can limit using the OPC connection, you should.

FWIW, I'd be delighted to have more NX testing of my EtherNet/IP client driver, which supports the NJ/NX family:

> [@Automation Professionals' EtherNet/IP Communication Suite V2](https://forum.inductiveautomation.com/t/automation-professionals-ethernet-ip-communication-suite-v2/68190/19):
>
> Tested driver with Omron NX102-1100, almost 4000 tags: Ignition NX driver: Sampling interval 13 600 ms This driver v2 (EthernetIP Class 1 Communications-2.0.1.230022328-v81), sampling interval less than 1000 ms, load factor 21%

/shameless plug

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