Reactor Logic Fail safe


I’m using a reactor board with USB module. I have custom software that enables/disables each relay. I’m trying to setup the Reactor Logic that if a timer finishes it will turn off all relays and i will use the software to reset the timer. This is for a fail safe application so that if the software crashes the relays won’t stay open.


  1. I assume i can use the “Execute Event Pipe Function” to control Timer 1?
  2. Is there a way to return control of relays to reactor logic once i’ve turn on a relay through commands?



  1. Yes, you can use the Execute Event Pipe Function to initiate Reactor’s Timer 1. Each time you send the command to initiate that timer it will reset, this would make it ideally suited for a Fail Safe timeout like you are describing.

  2. Yes, you can return control of the relays to Reactor. See page 45 of this guide:

If you have any other questions please let us know.

Thank you,
Travis Elliott

Thanks Travis,

I tried that and it seems to work, but what if the software crashes before i can issue the “Returns Control of All Relays to Reactor Logic” command. In this scenario, the rest of my relays will close except the one i forced open through software. Is there a way to set reactor logic to override all?

Hi Jon,

In this type of an application I would not recommend ever sending manual relay control commands to the board. Instead send commands to execute Reactor functions like triggering timer 1 which would turn relay 1 on. If your software wants to hold that relay on then just keep sending the command to trigger timer 1 and it will stay on until the timer expires.

Please let me know if that works for you,
Travis Elliott