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from the End Point Processes department...
S7-200 End Point Process
PLCs topic
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Posted by Dave A on 2 March, 2008 - 7:03 pm
Could someone point me in the right direction please?

I am using a S7-224 CPU with a Pro-face AGP 3400 HMI.

I have been asked wether I could give 2 end point values that are only reset when I enter into a new cycle.

1 of the values is an analogue value that is reading the motor current. The other value is the cyle timer that maybe interrupted during the cycle so the elapsed time would need to be recorded maually. Having limited experience of S7200s which do seem a little limited I am struggling. The cycle time value i am using is a 100ms timer, is there an easy way to convert this to minutes?

The summary is how can i get these values to freeze on my HMI until i start a new cycle.
Yours hopefully

Dave A.
davejkd2000 @ yahoo.co.uk

Posted by Marc Sinclair on 2 March, 2008 - 7:54 pm
Hi,

this is trivial, and well within the capabilities of the s7-200.

I know nothing about the HMI you are using, but I assume it displays a
variable at a V memory location.

To 'freeze' the analogue value, copy it to a new variable at the required
point. using the MOVE command

There are 600, 100mS's in a minute, but why not try the excellent interval
timers available? You cant start the interval timer, then calculate it when
you want to read it, then copy it to your storage variable using the MOVE
command.

The manuals on the CD and website are thorough and the micro/Win online help
is always there at the F1 key.

Marc Sinclair

Posted by Dave A on 8 March, 2008 - 10:56 am
Hi Mark
Thanks for the info mate. It does sound simple when you explain it. Very much appreciate it
I theink the short comings are my programming skils an not the S7-200.

Many Thanks
Dave A

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