Minimal Relay Module pulse duration


  • I have Relay Module with SA-105 alarm connected.
  • For some reasons (to notify something) I want to invoke really short sound.
  • I use command "node/generic-node:0/relay/0:0/pulse/set" with payload {"duration":10, "direction":true}.

It’s working OK almost all the time.
Although, sometimes, time by time, this command closes the relay permanently.

It leads to loud siren is triggered until I power off it by command "node/generic-node:0/relay/0:0/state/set" = false.

I need to achieve pulse short as possible but without error behaviour.
Unfortunately, this is very unpredicable, for example 2 times in month.
So it’s heavy to test it and find any suitable pulse duration.

Which minimal pulse duration is safe to use?


Hello, the pulse function was meant to trigger pulses 100ms or longer.

The issue here might be that the task scheduler is running in 10ms intervals and it can have issues if you call function with 10ms or less from time to time. My guess is that with 20ms it might work, but really this pulse function or relays at general are not suitable for this short pulses. I would suggest to set 50ms pulse to be on safe side.