average temp with a 3 hr span

Hi everyone, quick question. I need to know what the "ave" command looks like with in the SLC 500. is it similar to the plc-5 "ave" command. what i mean is the same parameters. who evr has info please let me know

I am trying to average the temps: 3 hr span. using data from 60 sec cycles, storing them into an N file and then writing the avg to a pen chart.

thanks

steve

See the KB Article found HERE

thanks for the file. I will have to wait until the plc comp is free so i can view it. Is there a way that i can view it, like pdf or something of that nature??

thanks

pdf attached

You might also consider this version.

I added a bell or whistle, and it is simpler for my taste (easier to understand when I have to look at it a couple of years from now).

Sorry for the last post, I made a mistake in my math figuring the average of all things.

But I just looked at Google and found the attached SLC500 file.

This should work.

WireGuy1950 said:

Sorry for the last post, I made a mistake in my math figuring the average of all things.

But I just looked at Google and found the attached SLC500 file.

This should work.

Click to expand...

wiseguy,

hey thanks for the info.

In general, you need a "Flying Window"...

3 Hours of 60-sec cycles = 180 readings.

You need a shift-register consisting of 180 elements.

Everytime a cycle occurs, add up(*) all of the 180 elements(**), then divide by 180. That is the average for the last 3 hours.

(*)This can be done more easily, when a cycle occurs, by subtracting the value that is being ejected from the shift-register from the total, and then adding the new reading to the total, and then dividing by 180. Then shift-in the new reading into the shift-register. At PLC Power-Up reset the total to zero.

(**)Keep count of the cycles that have occurred after power-up. If less than 180 cycles have occurred, then add up the valid entries and divide by that number of entries.

You should also consider controlling register content during down-time.

Thanks for all the info. I am using this as a average temp reading and then taking the output (average) to write to a pen device to plot the average temps over a 24 hr period.

I will be writing the logic this week sometime. will let everyone know if it works or not.

steve