Mitsubishi Q Series: Using the less-than operator on floating point numbers

Hi, In my ladder logic, I've got a data register D60 whose value is -0.001 (when using monitor mode to see values). D406 is 0.250.


But then later on I have a rung where I m checking if D60 is less than D406 (another FP value).


|---[ < D60 D406 ]------------------(M557)----|


However, in the above, D60 has the value -13332 & D406 has the value 0.


Why are they different? How can I do the < operator when dealing with two FP numbers?

ECMP instruction?

I believe it is because you are using a "standard" compare function. For floating point, you need to use compare funtions with an "E" prefix. for example, [E< D60 D406]. It has been a while since I used Mitsubishi, but this is what I remember.

Yes you need to use the E< function, remember E is floating point in Mitsubishi.
so E (< = >) is float
So ANDD [D< Dx Dx] is double 32 bit integer or bin
< = > is 16 bit

Nice one, chaps. I'll give it a try!

YES! That worked - you chaps are the BEST!