# ControlLogix OPC Extended Parameters **URL:** \ **Category:** Ignition\ **Tags:** ignition79, ignition80\ **Created:** [August 23, 2019, 4:16pm UTC](https://forum.inductiveautomation.com/t/controllogix-opc-extended-parameters/27723 "2019-08-23T16:16:13Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Tim.Johnson](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/tim.johnson/32/10597_2.png) [@Tim.Johnson](https://forum.inductiveautomation.com/u/Tim.Johnson)\ **Post date:** [August 23, 2019, 4:16pm UTC](https://forum.inductiveautomation.com/t/controllogix-opc-extended-parameters/27723/1 "2019-08-23T16:16:13Z")
Hello, does anyone know how to access ControlLogix _“Extended Parameters”_ using an OPC tag? This feature is available in FTView by using the “@” identifier (.@Description, .@EUMin, .@EUMax, etc) Does the Ignition dev team have any plans to develop this? Thanks, -Tim ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [August 23, 2019, 4:18pm UTC](https://forum.inductiveautomation.com/t/controllogix-opc-extended-parameters/27723/2 "2019-08-23T16:18:12Z")
It depends how FTView implements this, I guess. It’s certainly not in any documentation I have access to. ---
**Author:** ![Tim.Johnson](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/tim.johnson/32/10597_2.png) [@Tim.Johnson](https://forum.inductiveautomation.com/u/Tim.Johnson)\ **Post date:** [August 23, 2019, 4:26pm UTC](https://forum.inductiveautomation.com/t/controllogix-opc-extended-parameters/27723/3 "2019-08-23T16:26:59Z")
It’s used as a suffix on any OPC tag as a “dot field” (but not visible in the OPC Tag Browser). So your reference would be “[Device]TagInstance.@EUMin” It’s a HUGE advantage when it comes to data standardization. ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [August 23, 2019, 4:29pm UTC](https://forum.inductiveautomation.com/t/controllogix-opc-extended-parameters/27723/4 "2019-08-23T16:29:18Z")
Yeah, what I mean though, is that if this isn’t available via the CIP Read Tag service and is instead implemented by some proprietary or undocumented service, it’s unlikely we’ll be able to do it. I’ll have to get a Wireshark capture of the traffic between FTView and a controller when I have some free time. ---
**Author:** ![Tim.Johnson](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/tim.johnson/32/10597_2.png) [@Tim.Johnson](https://forum.inductiveautomation.com/u/Tim.Johnson)\ **Post date:** [August 23, 2019, 4:40pm UTC](https://forum.inductiveautomation.com/t/controllogix-opc-extended-parameters/27723/5 "2019-08-23T16:40:38Z")
Okay, sounds good. It became available in FactoryTalk View 9.00 or later and 21.00 or higher Logix Controller. Using “@Description” (string) is the easiest to test with. Good luck! ---
**Author:** ![Funguy](https://avatars.discourse-cdn.com/v4/letter/f/58f4c7/32.png) [@Funguy](https://forum.inductiveautomation.com/u/Funguy)\ **Post date:** [August 28, 2019, 4:07am UTC](https://forum.inductiveautomation.com/t/controllogix-opc-extended-parameters/27723/6 "2019-08-28T04:07:38Z")
According to the Knowledge Base: “Because these tags are not exposed via the FactoryTalk Gateway or RSLinx Classic OPC servers, they cannot be accessed through any third party OPC client.” ---
**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:** [August 28, 2019, 1:37pm UTC](https://forum.inductiveautomation.com/t/controllogix-opc-extended-parameters/27723/7 "2019-08-28T13:37:33Z")
> [@Kevin.Herron](#): > > I’ll have to get a Wireshark capture of the traffic between FTView and a controller when I have some free time. I wouldn't mind seeing what you come up with -- might be worth adding to my Ethernet/IP module. ---
**Author:** ![Steve.Perry](https://avatars.discourse-cdn.com/v4/letter/s/3be4f8/32.png) [@Steve.Perry](https://forum.inductiveautomation.com/u/Steve.Perry)\ **Post date:** [June 9, 2022, 5:49pm UTC](https://forum.inductiveautomation.com/t/controllogix-opc-extended-parameters/27723/8 "2022-06-09T17:49:12Z")
Has this become available since this post? (Aug 2019) Sure would be nice to pull the tag description from ControlLogix…