# UR+ Modbus-RTU Communication

**URL:** <https://forum.universal-robots.com/t/ur-modbus-rtu-communication/11435>\
**Category:** URCap Development\
**Tags:** modbus\
**Created:** [January 13, 2021, 3:26am UTC](https://forum.universal-robots.com/t/ur-modbus-rtu-communication/11435 "2021-01-13T03:26:51Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![weil](https://avatars.discourse-cdn.com/v4/letter/w/ac91a4/32.png) [@weil](https://forum.universal-robots.com/u/weil)\
**Post date:** [January 13, 2021, 3:26am UTC](https://forum.universal-robots.com/t/ur-modbus-rtu-communication/11435/1 "2021-01-13T03:26:51Z")

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I am developing an electric claw for UR+, but I did not understand how to communicate between my URCap and the tool. The electric claws uses Modbus-RTU communication. Thanks.

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**Author:** ![mmi](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.universal-robots.com/mmi/32/691_2.png) [@mmi](https://forum.universal-robots.com/u/mmi)\
**Post date:** [January 13, 2021, 10:40am UTC](https://forum.universal-robots.com/t/ur-modbus-rtu-communication/11435/2 "2021-01-13T10:40:01Z")

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If this is TCP/IP based communication then controller has script commands for adding modbus signals. Look for “modbus\_…” script commands.

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**Author:** ![weil](https://avatars.discourse-cdn.com/v4/letter/w/ac91a4/32.png) [@weil](https://forum.universal-robots.com/u/weil)\
**Post date:** [January 18, 2021, 6:45am UTC](https://forum.universal-robots.com/t/ur-modbus-rtu-communication/11435/3 "2021-01-18T06:45:24Z")

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I just use 485 communication

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**Author:** ![krmi](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.universal-robots.com/krmi/32/1945_2.png) [@krmi](https://forum.universal-robots.com/u/krmi)\
**Post date:** [January 18, 2021, 10:12pm UTC](https://forum.universal-robots.com/t/ur-modbus-rtu-communication/11435/4 "2021-01-18T22:12:12Z")

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Hi Weil,

UR does not natively support Modbus RTU, only Modbus TCP. For more info about Modbus, please visit the following links:  
[https://www.universal-robots.com/articles/ur/modbus-tcp-client-setup/](https://www.universal-robots.com/articles/ur/modbus-tcp-client-setup/)  
[https://www.universal-robots.com/articles/ur/modbus-server/](https://www.universal-robots.com/articles/ur/modbus-server/)

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**Author:** ![ANBR](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.universal-robots.com/anbr/32/2199_2.png) [@ANBR](https://forum.universal-robots.com/u/ANBR)\
**Post date:** [January 19, 2021, 1:02am UTC](https://forum.universal-robots.com/t/ur-modbus-rtu-communication/11435/5 "2021-01-19T01:02:56Z")

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