PLC5 to ControlLogix Upgrade

We are upgrading PLC5 -> Controllogix by turning the PLC5 into a remote rack of a ControlLogix processor.


A couple of concerns we have.
1st, The main PLC5 processor is communicating to a remote PLC5 via a 1771-KE card with modems in between.

2nd, The main PLC processor is communicating to other PLC5 processors via a 1771-AF card. We understand that the 1771-KE module is a protocol converter (232 <-> DH+) and that the 1771-AF card is a media converter ( Blue Hose <-> Fiber ).

Our concern is when we upgrade to controllogix, this main PLC5 chassis will become a remote rack. Will the AF and KE cards still function properly when they are not in the main chassis (Do they need a processor to function properly)?
Thanks

Steve Crotty said:

We are upgrading PLC5 -> Controllogix by turning the PLC5 into a remote rack of a ControlLogix processor.


A couple of concerns we have.
1st, The main PLC5 processor is communicating to a remote PLC5 via a 1771-KE card with modems in between.

2nd, The main PLC processor is communicating to other PLC5 processors via a 1771-AF card. We understand that the 1771-KE module is a protocol converter (232 <-> DH+) and that the 1771-AF card is a media converter ( Blue Hose <-> Fiber ).

Our concern is when we upgrade to controllogix, this main PLC5 chassis will become a remote rack. Will the AF and KE cards still function properly when they are not in the main chassis (Do they need a processor to function properly)?
Thanks

Click to expand...

Are you planning on using RIO or Controlnet?
If RIO, answer is NO,
C-NET looks as if is does not support communication cards in the remote rack either

We were planning on using RIO. I didnt think it would matter which because neither card is really communicating with the processor over the backplane (you have to wire DH+ to the cards), it just converting DH+ to either RS232 or Fibre (depending on the card).

Can I ask you what source you are using to say no to RIO and no to CNET?

That's an iffy thing. The KE module is a converter, no PLC required, as is the AF. HOW-ever... there's a question of converting the new system to use the "blue hose". It looks like you are trying to change the end devices without changing the comm medium? It would work with a PLC in the chassis (as now) but not without one.

Using DHRIO on a remote rack, which is what your plc will become, doesn't work.

Im not really sure what you mean by changing the end devices without changing the medium.

We want to keep the DH+ network, and we want to keep the end devices the same. The only thing we want to change is the PLC 5/25 processor to a RIO module (or controlnet if need be), and add a CLGX Rack with a processor and DHRIO card to talk to the PLC5 remote rack.

All rightie. Just curious, besides these PLC chassis, how much RIO do you have?

Steve Crotty said:

We were planning on using RIO. I didnt think it would matter which because neither card is really communicating with the processor over the backplane (you have to wire DH+ to the cards), it just converting DH+ to either RS232 or Fibre (depending on the card).

Can I ask you what source you are using to say no to RIO and no to CNET?

Click to expand...

The source for RIO is practical experience. Only cards that are supported with Clgx and RIO are those that use BTRs/BTWs, such as analogs and Basic modules.

For the C-NET, I opened up an existing Clgx project that has C-NET, added a 1771-ACN15, and had no options to add any type of rack or modules

Which is what I would expect. The processor or the adapter doesnt need to communicate to these modules. All they are is convertes (DH+ to RS232, and DH+ to Fibre).

I talked to tech support and they seem fairly sure they should work, really I was hoping there was someone out there that may have done something similar and can confirm they do work.

Thanks

The only thing the -KE and the -AF get from the chassis is power supply. The stand-alone versions -KF and -AF1(?) use the same boards - just enclosed in a surface-mounting case. Their only function is media conversion and do not require any sort of additional communication to a PLC processor.

Use ControlNet with 1771-ACNR15 adapters in the former PLC-5/25 chassis if you want performance similar to local I/O on the Classic PLC-5. If you can tolerate slower I/O performance, go ahead and use RIO.

Analog modules in remote 1771 chassis on ControlNet need BTR/BTW instructions just like they would if you used a 1771-ASB and RIO. The programming is identical, and they don't get entered into the I/O chassis configuration.

You probably don't need the 1771-KE anymore; it was there because the PLC-5/25 did not have an RS232 port. You can connect the ControlLogix serial port directly to that modem and it will happily emulate the PLC-5 addressing while communicating with the remote PLC-5.

The answer to the base question; "will a 1771-KE and 1771-AF work correctly with no PLC-5 in the chassis" is definitely yes.
Neither of them interact with the controller via the backplane.

Thanks for the confirmation Gerry / Ken! Much appreciated.

I trying to tranfer analog data from a 1771-ACN15 remote chassis to a 1756-L62 logix processor. The BTR in my ladder preogram seems to be working but I do not get any analog data (Only the diagnostic word from the card is received). what I am doing wrong and how can I fixed?????