View Full Version : count down timer

October 31st, 2008, 12:40 PM
I have a AB SLC500 and I am stuck on trying to figure out how to get my second timer to display the hours minutes and seconds into wonderware.
I cant seem to get it to work right.
I found a example somewhere on the internet and I lost it.
Then I messed it up somehow.
My times dont match up right.
I have being trying different ways to do it.
Can someone look at it and help me figure out how to get my timer to show the times right?
This is My first question.

CycleTimeHour N7:100
CycleTimeMinute N7:101
CycleTimeSecond N7:101
hour N7:100
minute N7:10
second N7:30

October 31st, 2008, 01:47 PM
A few things to keep in mind, SLC's TON function is not precise enough to do long term timing or for metering purpose.

There's two way that most people handle precise timing in SLC.

Use the S:35 (last scan in ms), add this up with tell you exactly (ok, close enough) how much time has elapsed.

I also seen people use the S:42/0 bit, which is supposed to flip every second as a second timer but my testing has shown this to be less than ideal because the scan time of the ladder might be longer than that and miss it.