# Moku:Lab LLB Slow Control PID bug

**URL:** <https://forum.liquidinstruments.com/t/moku-lab-llb-slow-control-pid-bug/720>\
**Category:** Moku:Lab\
**Created:** [May 26, 2023, 10:13am UTC](https://forum.liquidinstruments.com/t/moku-lab-llb-slow-control-pid-bug/720 "2023-05-26T10:13:06Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![todd](https://avatars.discourse-cdn.com/v4/letter/t/fbc32d/32.png) [@todd](https://forum.liquidinstruments.com/u/todd)\
**Post date:** [May 26, 2023, 10:13am UTC](https://forum.liquidinstruments.com/t/moku-lab-llb-slow-control-pid-bug/720/1 "2023-05-26T10:13:06Z")

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**Moku model: Moku:Lab**  
**Operating system: iPad app**  
**Software version:**

**Bug or support request description: On our Moku:Lab(s), there seems to be a bug in the PID controller of the slow control path in the Laser Lock Box application. Whenever the instrument is closed and re-opened, the value settings of the control (gain, integrator frequency, etc) reset to a default value. For example, the slow control PID gain is set to -40dB, locked, the app is closed, re-opened, and the instant that any button on the application screen is pressed, the slow control PID gain jumps suddenly to 0dB and causes a system unlock.**

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**Author:** ![Sam.Speece](https://yyz1.discourse-cdn.com/flex035/user_avatar/forum.liquidinstruments.com/sam.speece/32/191_2.png) [@Sam.Speece](https://forum.liquidinstruments.com/u/Sam.Speece)\
**Post date:** [June 6, 2023, 8:42pm UTC](https://forum.liquidinstruments.com/t/moku-lab-llb-slow-control-pid-bug/720/2 "2023-06-06T20:42:43Z")

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Which version of the iPad app and Moku:Lab are you using? We recently released a large update for the Moku:Lab which now uses the Moku: application on the iPad and not the Moku Master app anymore. I do not see this issue on the latest iPad app (v3.0.0) for the Moku: app.

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**Author:** ![todd](https://avatars.discourse-cdn.com/v4/letter/t/fbc32d/32.png) [@todd](https://forum.liquidinstruments.com/u/todd)\
**Post date:** [June 7, 2023, 6:46am UTC](https://forum.liquidinstruments.com/t/moku-lab-llb-slow-control-pid-bug/720/3 "2023-06-07T06:46:44Z")

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You’re absolutely right! We updated to 3.0.0 yesterday and the bug is completely resolved. No further issues on this topic. Thanks!