Modbus alarm “on value change” possible?

[graybricks]

Hello,

I’m using modbus master alarms with several clients set up, and it works great.

However, is there any way or workaround to trigger the alarm when the modbus register changes by some value? The comparison and time triggers aren’t quite getting the job done.

For example. A Modbus register value is currently 4.
Every time the value changes by 2, execute the alarm.
So execute once if it becomes 6. Execute again if it becomes 8. And so on.

Thanks for the help!

[Martynas]

Hello,

Thank you for reaching out.

Unfortunately, it isn’t possible to set up a Modbus alarm trigger that dynamically executes each time the register value changes by a specific increment (such as every increase of 2).

As a workaround, you could create multiple alarms set to trigger at each of the specific values (e.g., 6, 8, etc.), though this is more of a manual setup and not the most optimal solution.

Best Regards,

[graybricks]

Thanks, Martynas.

I ended up doing that.

There are around 400 alarms now, which makes the interface sluggish but it does seem to work as long as many alarms don’t occur at once. I might consider an external protocol convertor.