Hello all,
I have an issue with part of the attached program and in need of help understanding why this is, little bit of a description of what I’m trying to do.
I have a flow transmitter 4-20 mA output 0-2700 gpm, I trying to totalize the flow over an hour and store the value along with a date/time stamp. LAD3 is set-up to trigger evey second with a STI.
I have set the SCP instruction LAD3 Rung 1 to read the full span 2700 GPM and totalize over an hour just to see how the logic works out prior to implementing.
The issue comes along when the processor ( ML1100 SER.B 1763-L16AWA) is first put into run mode.
LAD 3- flow sample is taken 60 times added and then divided by 60 to get the GPM.
During the first 60 times the logic is executed the value in F208:2 would suspect to be 2700GPM but the value is 2745. This tells me there is something going on with the CTU C:200:0 counter during the first scan, since 2700/60=45, so at some point the counter counts 61 times, I’m just unsure of how this happens.
Definitely on the first scan the CTU counter does not increment to a 1 and I’m not sure as to why.
Please help me in understanding the logic scan of the CTU counter.
I have an issue with part of the attached program and in need of help understanding why this is, little bit of a description of what I’m trying to do.
I have a flow transmitter 4-20 mA output 0-2700 gpm, I trying to totalize the flow over an hour and store the value along with a date/time stamp. LAD3 is set-up to trigger evey second with a STI.
I have set the SCP instruction LAD3 Rung 1 to read the full span 2700 GPM and totalize over an hour just to see how the logic works out prior to implementing.
The issue comes along when the processor ( ML1100 SER.B 1763-L16AWA) is first put into run mode.
LAD 3- flow sample is taken 60 times added and then divided by 60 to get the GPM.
During the first 60 times the logic is executed the value in F208:2 would suspect to be 2700GPM but the value is 2745. This tells me there is something going on with the CTU C:200:0 counter during the first scan, since 2700/60=45, so at some point the counter counts 61 times, I’m just unsure of how this happens.
Definitely on the first scan the CTU counter does not increment to a 1 and I’m not sure as to why.
Please help me in understanding the logic scan of the CTU counter.