# Free Modbus Simulator for Modbus TCP & RTU to test URCap when there is no PLC

**URL:** <https://forum.universal-robots.com/t/free-modbus-simulator-for-modbus-tcp-rtu-to-test-urcap-when-there-is-no-plc/43339>\
**Category:** URCap Development\
**Created:** [September 17, 2026, 3:55am UTC](https://forum.universal-robots.com/t/free-modbus-simulator-for-modbus-tcp-rtu-to-test-urcap-when-there-is-no-plc/43339 "2026-09-17T03:55:57Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![gomathisankar](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.universal-robots.com/gomathisankar/32/607_2.png) [@gomathisankar](https://forum.universal-robots.com/u/gomathisankar)\
**Post date:** [September 17, 2026, 3:55am UTC](https://forum.universal-robots.com/t/free-modbus-simulator-for-modbus-tcp-rtu-to-test-urcap-when-there-is-no-plc/43339/1 "2026-09-17T03:55:57Z")

</div>

We have been using this free Modbus tool to test our urcap when there is no PLC or HMI available.

[https://tamidas.com/modbus-simulator](https://tamidas.com/modbus-simulator)

Just thought of sharing if anyone is looking for a free modbus simulator.

 ![modbus-siumator-ui](https://us1.discourse-cdn.com/flex020/uploads/universal_robots/original/2X/a/a8fb62671dc3ec4322e511ca79aefb8855a7e9f1.png)