Direct Way to get Running Average Value

[RBPLC]

Is there a direct way to get a running average for a value? Say I had a value at R100 and I wanted to "Start" averaging this value and store the average in R101 and then "Stop" at some other time (manual start/stop, sampling could be every scan or at some predetermined interval). I could probably come up with a solution but didn't know if there was a direct way to do this. 

[BobO]

Is there a direct way to get a running average for a value? Say I had a value at R100 and I wanted to "Start" averaging this value and store the average in R101 and then "Stop" at some other time (manual start/stop, sampling could be every scan or at some predetermined interval). I could probably come up with a solution but didn't know if there was a direct way to do this.

I would just use FILTER. Virtually the same results, without the effort.

[Garyhlucas]

At my last job we used a running average over 24 hours to set the rate that we processed waste water so the process ran very consistently.  I have the BRX code around here if that would help you.

[RBPLC]

Yes I would appreciate it.

[Garyhlucas]

Hope this helps.  Two examples shown here in the Math blocks, clocked by a minute pulse, and there are 1440 minutes in a day.

[PLCwannabe]

Use FIFO. Then use math to average the fifo table. Works great to get a rolling interval average, if that is what you need. 

[Controls Guy]

Yeah, FIFO's PROBABLY the best.  Ring accumulator works OK for storing the last n values too.