# OPC communication with Rockwell PLC **URL:** \ **Category:** Ignition\ **Tags:** vision\ **Created:** [July 23, 2024, 4:23pm UTC](https://forum.inductiveautomation.com/t/opc-communication-with-rockwell-plc/93612 "2024-07-23T16:23:32Z")\ **Posts on this page:** 1\ **Showing post:** 9
**Author:** ![michael.flagler](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/michael.flagler/32/26272_2.png) [@michael.flagler](https://forum.inductiveautomation.com/u/michael.flagler)\ **Post date:** [July 24, 2024, 4:45pm UTC](https://forum.inductiveautomation.com/t/opc-communication-with-rockwell-plc/93612/9 "2024-07-24T16:45:33Z")
One other recommendation I'll make is on the device configuration, be sure to leave the maximum concurrent requests at 2 (seems to be the sweet spot for me), but under advanced, change the connection size to 4000 bytes instead of the default of 500 bytes unless you're talking to an old processor through like an old ENBT card. @pturmel also has a great driver that is much faster than the built-in driver, but that all depends on if this is Ignition Edge (custom modules like his can't be used on Edge). While it is an additional cost, if you're not able to change the structure of the PLC to get faster comms, his driver may help. @pturmel I'd b curious about the 4000 byte connection size and how it relates to MTU size of ethernet considering this is larger than the default MTU of 1500 bytes. Do packets get fragmented, or do both ends automatically know to break up the request into multiple packets? > [@Automation Professionals' EtherNet/IP Communication Suite V2](https://forum.inductiveautomation.com/t/automation-professionals-ethernet-ip-communication-suite-v2/68190): > > Automation Professionals is pleased to announce its latest EtherNet/IP Communications Suite driver module, a major upgrade to its EtherNet/IP Class1 Communications module, as a Public Beta. As of April 15, 2023, this is now a Production Release. The primary new feature is its new Generic EtherNet/IP Client Driver, a drop-in replacement for IA's Logix V21+ driver and its Omron NJ/NX driver. It does work with older Logix processors, and also works with Rockwell's MicroLogix 8xx family (ethernet… --- _[View the full topic](https://forum.inductiveautomation.com/t/opc-communication-with-rockwell-plc/93612)._