Time interval copy- Need help

[dabanani]

Hi all,
I have been programing a move instruction of an analog signal into a data block every 30 seconds. For some reason the time works but data is not being moved. Please Help. Is there better way to move data than move instruction?

In this program i used a timer for 30 sec and activate move instruction with timer done bit. When I run the program, it seems like timer done bit never comes true.

Software: Siemens TIA software V12

Thank you.

 

[cwal61]

Put your timer below the Move. Logic is solved from top to bottom.

 

[Eric Nelson]

Put your timer below the Move. Logic is solved from top to bottom.

What am I missing here? I would fully expect dabanani's code to function as he planned it to. This is how I would generate a one-shot every 'x' seconds (and BTW, the positive differential (-|P|-) should not be needed)

The timer's 'done' bit (.Q in this case) should remain on until the timer's rung gets scanned again, which would reset it (IOW, ON for one scan).

Do the newer S7 PLCs have an asynchronous scan?



-Eric

 

[moggie]

What am I missing here? I would fully expect dabanani's code to function as he planned it to. This is how I would generate a one-shot every 'x' seconds (and BTW, the positive differential (-|P|-) should not be needed)

The timer's 'done' bit (.Q in this case) should remain on until the timer's rung gets scanned again, which would reset it (IOW, ON for one scan).

Do the newer S7 PLCs have an asynchronous scan?



-Eric

From an older post -

- In S7 300/400 plc's the timers update asynchronously to the scan of the program. .......

 

[Eric Nelson]

Thanks, moggie. That explains it.



-Eric