Hi,

I'm havin some difficulties setting up a timed output for a motor of a gate.

From the client specification the gate should be able to open all the way, close all the way, stop and position to a certain percentage that is read from a probe.

Only during the last command the gate should move for a certain time and then rest for a little bit and so on until it reached the percentage.

For the "open all the way" and "close all the way" commands they reset the other commands  and set the open or close output.

The "position" command is set up like this

And the outputs of the first two lines are the inputs for the timed output that doen't work, infact it just wait for the first timer and then just set the output and never reset it

This metod for timed output usually works but inside this FB it doesn't.

The parameters are grouped inside a dataType that is positioned in the InOut parameters, I tried to detach them and put the output only in the Output parameters but it didn't work.

I see two potential issues with this timer network:

1. Using instance DBs instead of multi-instances. This isn't necessarily wrong, but you have to be careful with it. Make sure your program doesn't use these same instance DBs elsewhere for other timers. You mention you're calling this code in an FB. If you use that FB more than once, each copy will access the same timer, leading to unexpected behaviour. Use multi-instances inside your FB to avoid this potential headache.
2. Accessing the Timer.Q output directly. The internal state of an IEC timer is updated each time its output is checked in the program, which can lead to inconsistent behaviour. Just because Timer.Q was FALSE in one network doesn't mean it's still FALSE in the next. To avoid this, write the timer output to a temp or static variable once, then access that variable whenever you want to check the state of the timer. Here is some further reading on these timers.

I suspect you'll see your problem disappear once you've tackled these issues. Do let us know what you discover.

Hi,

sorry for the long wait but we decided to not modify the program because it was already operating and the timed output wasn't used most of the times.

Today I updated the program and decided to tackle the issue: I followed your second suggestion and it worked. I created a static varaible for each clock and those are the one that sets and reset the output of the motor.

Thanks for you help

pegu