Analog Card Upgrade

Hi,

I have a project on at the moment that has a control logix processor 1756-L61 connected to a PLC 5 remote rack via a 1756-DHRIO.

Now in the PLC5 rack is a 1771-IFE Analog Input Card. We are upgrading the remote rack to a control logix rack and it will be using a 1756-IF6I card instead.

When I looked at the config of the 1771-IFE it was setup to use two's complementary as the data format. I was hoping to just move the input data from the new card into the register that was holding the input data from the old card.

Will the new data be the same as the 2's complement data assuming I have set the scaling the same??

Thanks,
Tony.

Unfortunately, the Legacy 1771-IFE Analog Input modules provide a 12-bit resolution while the 1756 family Analog Input modules carry a 16-bit one.
The only data format choices for the ControLogix Analog modules are Floating Point and Integer.
In your case, since the replaced and replacement module carry different resolutions, you will have to redo the scaling; in order to be able to scale a 1756 Analog module you will have to choose a Floating Point module data format.
Refer to Pages 49-50 of http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1756-um009_-en-p.pdf
vs.
Page 4-3 of
http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1771-um663_-en-p.pdf