Nonconvertible PLC-5 indirect addressing

[phuz]

Running into a PCE that I haven't encountered before. They are using indirect addressing for a recipe structure and you can't use the same format in Logix.
Just curious what you guys have done for minimally invasive workarounds.

 

[MaReKA]

I guess they have used different integer datafiles Nx .. Ny to create a two dimensional structure. Each datafile contains the values for one recipe. N7:0 would then be a recipe index, N[N7:0]:5 one of the recipe parameters.
The Logix equivalent would be a two dimensional array like INT[x,y], where x would be the recipe index and y the recipe parameter. Look at the datafiles referenced by N7:0 to see how many parameters you will need. Search for the upper and lower limits of N7:0 to see how many recipes you will need to recreate. You will have to edit the indexing logic though.

 

[phuz]

Adding indexing logic was one of my thoughts, but it appears to be only 12 recipes, so a simple index comparison to the value followed by its respective COP instruction will suffice for this one.

Thanks for your reply.

 

[RonJohn]

If I'm thinking correctly, I have run across this issue before. I'd be inclined to avoid two dimensional arrays as I don't like how they're laid out in the tag database, among other things. If it were me, with only 12 recipes, I'd use compare & copy logic like you suggested.