Micrologix Datalogging Floats

Has anybody figured out a workaround how to datalog floating numbers in Micrologix 1100/1400? I know, you can multiply the floating number by 100 & convert it to an integer before loggin it, but then you need to divide it by 100 when you extract the data. Is there any other way?

Jr.

You could copy them to integers. You'll need twice the number of integers for the number of floats you want to store. The COP instruction performs a bit for bit copy. The Length refers to the number of destination elements, so set it at 2 to COPy one float to two consecutive integers.

You will still have to COPy them back to floats or interpret them as floats when they're retrieved.

Thanks, I was hoping there was something where you wouldn't have to interpret them once the data is retrived. I think the easiest would be to multiply the float by 100 in the PLC then use the MOV to move it into an integer register. Once retrived, then divide the data logged by 100.

The problem with this is if you have lots of data, it's a bit of a pain to write a macro to divide everything by 100.

Jr.

Oops...you'll have to use the CPW command with a Micrologix controller if that method is useful to you. The COP method works fine with a SLC or PLC5, but RSLogix doesn't like it when the data types are different element sizes when programming a Micrologix.

Actually it looks like the ML1400 supports logging floats, so it seems to be a better choice then the ML1100