# Sending large hex value via OPC tag **URL:** \ **Category:** Ignition\ **Created:** [July 11, 2023, 2:18pm UTC](https://forum.inductiveautomation.com/t/sending-large-hex-value-via-opc-tag/76191 "2023-07-11T14:18:56Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Andrea\_Salmaso](https://avatars.discourse-cdn.com/v4/letter/a/4da419/32.png) [@Andrea\_Salmaso](https://forum.inductiveautomation.com/u/Andrea_Salmaso)\ **Post date:** [July 11, 2023, 2:18pm UTC](https://forum.inductiveautomation.com/t/sending-large-hex-value-via-opc-tag/76191/1 "2023-07-11T14:18:56Z")
Hi! I have the hex value in the attachment: is it possible for the machine that generates (equipped with a PLC) it to send it to Ignition via an OPC tag? Thanks [value\_sample.txt](https://forum.inductiveautomation.com/uploads/short-url/8NuMlSNzxOE1Z1Yttyv5u0a2CTI.txt) (16.3 KB) ---
**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 11, 2023, 2:19pm UTC](https://forum.inductiveautomation.com/t/sending-large-hex-value-via-opc-tag/76191/2 "2023-07-11T14:19:59Z")
OPC UA supports byte arrays, so I'd think so. ---
**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:** [July 11, 2023, 2:20pm UTC](https://forum.inductiveautomation.com/t/sending-large-hex-value-via-opc-tag/76191/3 "2023-07-11T14:20:12Z")
What kind of PLC? What protocol? You could stuff the value into a String and parse it on the Ignition side. ---
**Author:** ![Andrea\_Salmaso](https://avatars.discourse-cdn.com/v4/letter/a/4da419/32.png) [@Andrea\_Salmaso](https://forum.inductiveautomation.com/u/Andrea_Salmaso)\ **Post date:** [July 11, 2023, 2:44pm UTC](https://forum.inductiveautomation.com/t/sending-large-hex-value-via-opc-tag/76191/4 "2023-07-11T14:44:28Z")
We're gonna use OPC UA. I don't know the details of the PLC at the moment. Ok, so I could use a String tag...what's the size limit for this kind of tag? ---
**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:** [July 11, 2023, 2:46pm UTC](https://forum.inductiveautomation.com/t/sending-large-hex-value-via-opc-tag/76191/5 "2023-07-11T14:46:29Z")
There's no size limit on an OPC tag. Ultimately the largest value you can send over OPC would be dictated by the connection details negotiated between client/server, but that usually ends up being multi-megabyte max size. ---
**Author:** ![Andrea\_Salmaso](https://avatars.discourse-cdn.com/v4/letter/a/4da419/32.png) [@Andrea\_Salmaso](https://forum.inductiveautomation.com/u/Andrea_Salmaso)\ **Post date:** [July 11, 2023, 3:00pm UTC](https://forum.inductiveautomation.com/t/sending-large-hex-value-via-opc-tag/76191/6 "2023-07-11T15:00:02Z")
You wouldn't see any problem in sending a tag with that value then, correct? ---
**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:** [July 11, 2023, 3:01pm UTC](https://forum.inductiveautomation.com/t/sending-large-hex-value-via-opc-tag/76191/7 "2023-07-11T15:01:31Z")
Should be okay, only ~17k characters... Not great if it's changing often but should be okay. What's this for? ---
**Author:** ![Andrea\_Salmaso](https://avatars.discourse-cdn.com/v4/letter/a/4da419/32.png) [@Andrea\_Salmaso](https://forum.inductiveautomation.com/u/Andrea_Salmaso)\ **Post date:** [July 11, 2023, 3:14pm UTC](https://forum.inductiveautomation.com/t/sending-large-hex-value-via-opc-tag/76191/8 "2023-07-11T15:14:20Z")
That should be the hexadecimal representation of a set of value the machine (a press) provides as output at the end of every cycle. It then needs to be converted into a readable format so we can use it to generate a chart of the force.