I will like to have the hour be the indirect address, like this:

[piscis]

Why is the AB1500 giving me this error:

 

[bernie_carlton]

Are you just trying to make a table of values indexed (indirect) by the hour? You may not need to use the FFL command. Just use a MOV with an indirect destination.

Otherwise let the FFL command do its thing. If you trigger it once per hour then the pointer in the FIFO will adjust downward as it fills the FIFO. Unloading using the FFU command pulls off the top and shifts everyone up one.

 

[piscis]

Bernie:

I need to show on the HMI the total KWH consumption every hour for the last 24 hours. If time shows hour number 6 am then the KWH value should be stored on register N102:6. But!

What happens if there is not electric power and the PLC is down for two hours. Next time is turn back on, how would she knows where to store the next KWH value if the control word R6:2 is not synchronized any longer? The way I wanted to do it was using the S:40 to synchronize. Do I make sense?

 

[piscis]

I think this did it!

 

[bernie_carlton]

Also:

MOV S:40 N7:1
MOV N12:1 N102:[N7:1]

No FIFO commands, unless you really need them.