Histogram for Microligix1000 & SLC500

I like to know if I can check different inputs and outputs in histogram. For example, I:1/1, I:5/3, O:3/2, O:3/7 in histogram? Is there anyway to write a program to monitor above I/Os like histogram? I mean just keep these informations in PLC only when I want, I will hoock up a PC to see how long and often the I/Os are on and off?
I'm using microligix 1000.

RSLogix500 has a built in histogram feature. There are some limitations. I usually don't use the histogram to try to detect digital inputs that change states twice in less than 20ms.

You can "map" those digital addresses to consecutive bits and use the built in RSLogix histogram on the whole word containing the bits.

As far as PLC programming to log information, yes it's not too hard, just depends on knowing what you need to log.

Look at the RTO timer to accumulate the total time that a bit is on.

Hope this helps!

Thanks for the reply. What I like to do is to keep the down time events. Is it possible to use shift register to keep these events with down time included? Like when you look at data table you'll be able to see som number that represents second or minute?
121 234 3223 454 677 766 something like that.

First, be specific.
Figure out exactly what information is needed and exactly how accurate is needs to be including units. Understand when the log will be recorded and/ore reset. You only have 1k in a ML1000, so you can only do so much. It's easy to record things like:

Total Time Running (XIC RUNNING_BIT RTO RUN_TIME)
Total Time Stopped (XIO RUNNING_BIT RTO STOP_TIME)
Number of times started (XIC RUNNING_BIT CTU START_COUNT)
Number of times stopped. (XIO RUNNING_BIT CTU STOP_COUNT)

From those few values, you can calculate average time running and average time stopped, and do quite a bit of analysis.

If you need to log the individual occurrences with a timestamp, the ML1000 is going to limit you with it's 1k user ram. If you absolutely must log to this level of detail, you're better off buying a datalogger, or a Panelview or other operator interface with that capability.