TwinCat2 TON no way to override the elapsed time?

[g.mccormick]

I have some code that is going to trigger calculations to happen either when "A" happens, or every 1 second.

For the 1second trigger, I am using a TON.

When the "A" happens, I wanted to reset the 1second timer so that the calculations don't happen twice (ie. one scan due to A then next scan due to 1secondtimer.Q).


Is forcing the .ET not allowed?

 

[tim2]

Couldn't you just use the A condition in a NC contact instruction to enable the TON. TON will run if A is not on, A turning on turn the NC A instruction off and will disable and reset the TON instruction?

I know nothing about TwinCAT but seems like this would work on the platforms that I know.

 

[Archie]

I would need to check this but I'm quite sure the ET is calculated based on a start time. And the start time can be changed.

 

[g.mccormick]

I just added more logic into the enable

Tmr_TimeSinceCalc(IN:= ( NOT Trigger_Bool AND NOT Tmr_TimeSinceCalc.Q) , PT:=T#1s );

The Trigger_Bool is always set to FALSE at the start of the scan, then if "A" happens it is set to TRUE. This is all ahead of the timer in the code.

I was just surprised that I could not just simply set ET to 0 like I can/do in other PLCs.