Addressing SLC IO in Control Logix

I have an existing SLC system that we are planning on putting a new CLX processor on top of. My question is how to address the following SLC IO in Logix. I have two racks of SLC IO each are 13 slot racks, the first rack slot 0 had the SLC 505 which will now be a 1747-ASB. I am using a 1756-DHRIO card to talk to the IO but I am not sure how to address these two racks in logix. The second rack is an expansion rack, but I think I am going to have to add virtual ASB modules into logix to address the SLC IO even though the do not really exist because Logix can only see 8 cards at a time. Am I on the right path here? Any advise would be greatly appreciated.

Yes, you are on the right track. If you have access to the AB/Rockwell Knowledgebase this is described in 19047. If not I can try and describe it.

Stu.....

The 1747-ASB can control up to 30 I/O modules, so two 13-slot chassis joined with a backplane extension cable can address 25 modules (the -ASB takes up the first slot).

Under the adapters under the 1756-DHRIO scanner channel, you'll need three or four adapters.

Each "Full Rack" adapter will address eight slots, so you'll have:

Rack 00 = Slots 1,2,3,4,5,6,7,8
Rack 01 = Slots 9,10,11,12,13,14,15,16
Rack 02 = Slots 17,18,19,20,21,22,23,24
Rack 03 = Slots 25, 26 (1/4 Rack, with Slot 26 unavailable)

This is for the most common "Single Slot" addressing mode which uses mostly 16-bit I/O modules. All analog modules, of course, will have to be configured with Block Transfer MSG instructions in the Logix controller.

Ken Roach said:

The 1747-ASB can control up to 30 I/O modules, so two 13-slot chassis joined with a backplane extension cable can address 25 modules (the -ASB takes up the first slot).

Under the adapters under the 1756-DHRIO scanner channel, you'll need three or four adapters.

Each "Full Rack" adapter will address eight slots, so you'll have:

Rack 00 = Slots 1,2,3,4,5,6,7,8
Rack 01 = Slots 9,10,11,12,13,14,15,16
Rack 02 = Slots 17,18,19,20,21,22,23,24
Rack 03 = Slots 25, 26 (1/4 Rack, with Slot 26 unavailable)

This is for the most common "Single Slot" addressing mode which uses mostly 16-bit I/O modules. All analog modules, of course, will have to be configured with Block Transfer MSG instructions in the Logix controller.

Click to expand...

Very well explained Ken. I read in the Tech Note I quoted above, that you don't have to define Digital Cards under the ASB Modules, but that you do have to define any Analog and I assume any specialty Cards. Any comments?

Stu.....

See attached.... this may help

Its an L55 in a 10 slot rack with other I/O and a DH/RIO, if you look at the "Old Logic" you will see a 13 slot that had a 5/04 removed and replaced with a ASB, I would also suggest you split up the logic from old to new... it helps when debugging and troubleshooting

Look at the tags names (in the old logic).... we named them the old (SLC) address so it would make more sense for someone that did not know CLX but knew the addressing of the SLC

The reason we did this... the 5/04 was full also no more room in the cabinet and this gave us the chance upgrade (kind of, most parts were spares) but we added the Ethernet, Redlion HMI and that gave us a lot of spares

Its a few years but should still help