90/30 Addressing

[gumpus 0]

I have been using mostly AB PLCs for the past 20 years. I have started a new job where everything is GE. I have used them some in the past so I'm not totally blind. I am starting an equipment refurb/upgrade project where I will possibly need some more IO (the rack is full). I plan to swap the current three 16 bit input cards out with three 32 bit cards. The 3 cards are all side by side. As far as addressing and the current program, nothing throws a red flag up to me. As I see it, swap the 3 cards and setup the hardware. The existing inputs shouldn't change address since they are sequential?? I guess the questions is will the addressing change when I combine the original three 16 bit cards to one and a half 32 bit cards? It will still be %I1 to %I48 now with an extra 48 bits free. Correct?

[Steve Bailey 118]

As long as the addresses of the three existing cards are sequential it will be easy. GE PLCs don't force you to sequentially address the modules but most people do. For example, if the first card is addressed to %I001 - %I016, the second card to %I017 - %I032, and the third to %I033 - %I048, you can address the new cards to %I001 - %I032 and %I033 - %I064. The inputs from the original first card will go to the first half of the first new 32-point card and the inputs from the original second card will go to the second half of the first new card. The inputs from the original third card will go to the first half of the second new card. However, it is possible that the original cards are addressed to %I001 - %I016, %I065 - %I080, and %I145 - %I160. If something like that is the case in your system, you'll have more work to sort out the addressing in the new configuration because all 32 inputs on each new card will be sequential.

[gumpus 0]

Thanks. I thought that was the case if they were sequentially addressed. I just wanted to make sure before I got in too far.