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View Full Version : Programming a production totalizer in RS Logics 500.


AB2005
September 1st, 2013, 05:23 AM
Hi;


When a machine runs, my SLC 5/05 receives an analog speed reference 0-10V which is equal to 0-300Meters/min (N7:1 in attached screen shot of sample program). I want to program a production totalizer to display the production of whole day for which I designed a sample program which screen shot is attached. But I have found that the totalizer doesn’t work accurately because of (for me) PLC scan time issues. Please check and suggest any other way by using speed ref 0-10V.

iant
September 1st, 2013, 09:29 AM
there are two ways to do this
1st add a ONS contact in series with the T4:1.DN contact
OR
delete the counter
use an ADD function
Add 1 to F8:1 ( floating point) higher range using the ONS as decribed

Lancie1
September 1st, 2013, 10:38 AM
I think your method might be flawed. I am not sure your formula is correct. Usually the timer has a fixed preset, and for each fixed time period, the length measured by the analog input in meters is added to the totalizer. With a variable time, I don't know what the time is supposed to represent.

Your result may be affectd by rounding errors in the integer computation. You could reduce those by using a fixed time period and a floating-point calculation for the length in Meters for that fixed time period. For example, as Ian said, use F8:1 to contain your total length. Set the timer to a fixed preset, say "10" with the same time base of 0.01. The for every time the timer goes DONE, compute F8:1 = F8:1 + N7:1/600.

iant
September 1st, 2013, 06:48 PM
I didn't look at that.
Well spotted