Siemens RTO timer

[Pandiani]

Hi, how to make timer in Step7 to behave like RTO timer in AB?
In AB RTO is working while iput is 1. When input is 0 RTO stops and again when input is 1 it continue working from existing value until it reaches preset value. There is retentive on delay in Step7 but it continue to work if input is changed from 1 to 0.
For example timer is supposed to timing 10 sec. If input is stopped (1 -> 0) at 5th sec. timer will retain current value, and when input change from 0 to 1 it will continue working from that value (5) to the end (10 s).
Any help would be greatly appreciated

Thanks

 

[PLucas]

Pandiani

If you use the standard on delay timer, this should behave the way you want it to.

To start the timer, the start input has to change from 0 to 1, if the start input is then changed back to 0, the timer stops but the time remaining is retained. When the start signal is then changed back to 1 the timer continues from where it left off.

Just remember that these timers count down not up.

Paul

 

[dchartier]

Hello Pandiani;

If you open the "TI-S7 converting blocks" library (in the Step7 programming editor) you will find all sorts of interesting (non-Siemens type) blocks: drums, decoding blocks, table move instructions...
In your case, you might be interested in FC80 in that library; it is named TONR (timer retentive), and it seems to do exactly what you want. Just insert it in a cyclic OB (OB1 comes to mind) in your S7-300 program. If you already have a FC80 defined, you can rename it without problem.
Look up details in the online help, or on the TI-S7 conversion PDF file included in the Step7 documentation.
Hope this helps,
Daniel Chartier

 

[Pandiani]

Well, it's not behaving like that.
When input signal change from 1 to 0. timer stop but whe it changes back from 0 to 1 timer start counting from 10 sec (reset itself).