# Twincat 3 O2T register error

**URL:** <https://forum.universal-robots.com/t/twincat-3-o2t-register-error/30232>\
**Category:** Robot Communication\
**Created:** [August 31, 2023, 1:34pm UTC](https://forum.universal-robots.com/t/twincat-3-o2t-register-error/30232 "2023-08-31T13:34:36Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Berbatov98](https://avatars.discourse-cdn.com/v4/letter/b/c67d28/32.png) [@Berbatov98](https://forum.universal-robots.com/u/Berbatov98)\
**Post date:** [August 31, 2023, 1:34pm UTC](https://forum.universal-robots.com/t/twincat-3-o2t-register-error/30232/1 "2023-08-31T13:34:36Z")

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I have a UR5e Robot communicating over PROFINET. I can access the device in Twincat 3 and the PROFINET LED in the Fieldbus menu is also Green on the Robot. However, in Twincat 3 under the Profinet API all my 02T Output registers are in a BYTE format. This makes me unable to communicate with the robot. I am aware that you have a UDT file that reformats these registers and turns them into BOOL, INT, FLOAT registers in a Siemens environment.  
How can I achieve the same in Twincat 3 with a Beckhoff IPC ?

 ![10](https://us1.discourse-cdn.com/flex020/uploads/universal_robots/original/2X/6/684781971adf41b5ba8d4a78740f094f55a9fad3.jpeg)  
 ![11](https://us1.discourse-cdn.com/flex020/uploads/universal_robots/original/2X/e/ed1cc2d296349fbcd5cfa18d53dbb3a4de19a8b6.jpeg)

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**Author:** ![10632069](https://avatars.discourse-cdn.com/v4/letter/1/839c29/32.png) [@10632069](https://forum.universal-robots.com/u/10632069)\
**Post date:** [December 5, 2025, 7:18pm UTC](https://forum.universal-robots.com/t/twincat-3-o2t-register-error/30232/2 "2025-12-05T19:18:42Z")

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Did you ever figure it out. I am working on a ur3e and have the same problem