RSLx 5000 comparing bool array

[DairyBoy]

Hello all. I'm looking for a direct (single instruction) way to check a 128 bit bool array for non-zero status. Is this possible? Thanks.

Edit: Daba, I have looked at your solution (and others) in another thread but as that one was about comparing two bools, I was hoping that cmp>0 may be more straightforward.

 

[Darkzadow]

Since your searching an array as opposed to using an DINT to store the bools a compare command only is used on Ints, dint, reals. You can use FSC, file search and compare, command to search for an non zero element of an array. This command compares each element in the array so worst case time scenario is that all Bool are 0. Of course you can make your own compare instruction in logic

 

[DairyBoy]

Thanks Darkzadow, it looks like the right thing for the job but having tried various expressions (and looked at the online help), I can't get it error-free. Can I use the expression "bool_array>0" or is that too simple? Should the length be "1" for one array or "4" for 4 x 32 bits? Can I use the .DN bit to reset the .IN bit so that it cycles continuously and follows the expression all the time? I'm a bit lost.

 

[Peter Nachtwey]

I would simply map 4 DWORDS over the 128 bit array. Then I would use one rung to OR the 4 DWORDS and check if the result is not zero.

 

[Steve Etter]

While it's probably not even close to any "elegant" way of doing it (and assuming you are using RSLogix5000) you could use the "FOR" function, test each value separately, and then use a counter to capture the results.

 

[DairyBoy]

Thanks Steve & Peter. I think 5000 is just too complex for some applications. 500 has many neat tricks that seem to need reinventing in 5000 but customers look twice if the "old" model is suggested these days.