# Q: What is the relationship between ITC-100 controller and SSR?

**URL:** <https://community.inkbird.com/t/q-what-is-the-relationship-between-itc-100-controller-and-ssr/101>\
**Category:** Questions & Answers\
**Tags:** smart-controller\
**Created:** [October 15, 2021, 3:16am UTC](https://community.inkbird.com/t/q-what-is-the-relationship-between-itc-100-controller-and-ssr/101 "2021-10-15T03:16:18Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![INKBIRD](https://yyz1.discourse-cdn.com/flex031/user_avatar/community.inkbird.com/inkbird/32/366_2.png) [@INKBIRD](https://community.inkbird.com/u/INKBIRD)\
**Post date:** [October 15, 2021, 3:16am UTC](https://community.inkbird.com/t/q-what-is-the-relationship-between-itc-100-controller-and-ssr/101/1 "2021-10-15T03:16:18Z")

</div>

A: PID do not turn on/off SSR. PID outputs PWM signal or output close signal to SSR. SSR controls load synchronously.

PID does not support PMW driver, it only supports SSR.

SSR is a optoisolated solid-state relay, which uses low voltage to control high voltage.