# Ignition Response Time **URL:** \ **Category:** Ignition\ **Created:** [May 28, 2025, 6:23am UTC](https://forum.inductiveautomation.com/t/ignition-response-time/106755 "2025-05-28T06:23:17Z")\ **Posts on this page:** 1\ **Showing post:** 2
**Author:** ![nminchin](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/nminchin/32/6911_2.png) [@nminchin](https://forum.inductiveautomation.com/u/nminchin)\ **Post date:** [May 28, 2025, 6:55am UTC](https://forum.inductiveautomation.com/t/ignition-response-time/106755/2 "2025-05-28T06:55:47Z")
What type of tags are you reading? If you're reading AOI parameters, you won't get much performance out of it.and if you're reading only UDT members but have _any_ members in the UDTs not set to at least Read external access, you always won't get good performance. Rockwell have deliberately shot themselves in the foot by not publicly releasing the documentation for efficient access to aoi parameters, however obviously their own software utilises methods to make comms to aoi parameters efficient, which is most likely why you're seeing the difference. If you can't use UDTs in the plc and you're not using plantpax v5 (comms to v5 will _always_ be terrible), then you can also use Phil's [Automation Professionals' EtherNet/IP Communication Suite V2](https://forum.inductiveautomation.com/t/automation-professionals-ethernet-ip-communication-suite-v2/68190) to read aoi params efficiently, as he has reverse engineered the protocol. Reading only UDT members, I've tested reading 8000 tags from an L82 @ 10ms. Make sure to increase the cip size as well up to 4000, depending on controller > [@Ignition & Logix Best Practice Tips for better communications](https://forum.inductiveautomation.com/t/ignition-logix-best-practice-tips-for-better-communications/60386/52): > > I always forget about this... Holy moly Edit: Updated results with tests using different CIP Connection sizes: Test Ext Access CIP Connection Size Tag Count Sample Rate (ms) Actual Sample Rate (ms) Request Count Overload UDTs All Read/Write 500 6787 10 45.48 14 355% UDTs All Read/Write 4000 6787 10 10.06 2 1% AOI Local Tags (UDT) All Read/Write 500 6787 10 50.86 14 409% AOI Local Tags (UDT) All Read/Write 4000 6787 10 10.08 2 1% AOI Parameter Tags All Rea… --- _[View the full topic](https://forum.inductiveautomation.com/t/ignition-response-time/106755)._