SLC to Logix Indexing Translation Trouble

Hello,

Please see the attached rungs of some sort of indexed sampling routine that is currently in a SLC500. I am tasked with migrating to a Control/Compactlogix controller and this does not translate properly. Throws a PCE of 105 ID/PCE013.

I am wondering how I can migrate these files? Create a new array of some sort? There isn't a lot of wiggle room to test on this application in real time.

Any insight is always appreciated.

Thanks,
b

The best approach to solve this is to create a new two dimensional array tag and then populate it with the values from the old program. Depending on how many files and words are used in the old code, this could be tedious. It would be worth considering a different approach to the problem if we had some perspective of the purpose of that part of the logic.

use two-dimensional arrays, and shift down, numerically, the values placed in N7_7, from whatever the a positive minimum value* was on the SLC, to 0 on the Logix.

* that positive minimum value is for the first Data File F[N7:7] that is used e.g. if N7_7 ranges from 53 to 60 for Data Files F53 to F60 on the SLC, then on the Logix, N7_7 will range from 0 to 7, to access row F_2D_ARRAY[0,N7_6] to row F_2D_ARRAY[7,N7_6].


F_2D_ARRAY is the tag for a two-dimensional array.


So F[N7:7]:[N7:6] becomes F_2D_ARRAY[N7_7,N7_6], but you will need to change the calculation for N7_7 slightly; the most likely case is that the N7:7 on the SLC startes with some value from 0 to N-1 (or 1 to N), and then the lowest file number (53 in the example above) is added to it. You may be able to simply eliminate that ADD, but you should also check anywhere else N7:7 is used.


[update: OkiePC got there first]