AB PLC2 -> Ctrl LGX Conversion

Hi everyone!
I am currently in the process of converting last 2 PLC2 (not sure which exact version) to Control Logix PLC. I have already done the ladder and since old plc were much simpler i had no problem with software conversion.
This particular line goes down on Thursdays so that is the only day that I can work on the PLC. I have spend last Thursday in trying to get hardware part correctly but with NO success.

This is my setup:

PLC2
It has 2 RIO (1 and 2) racks, that are connected with some old type of the cable. Not really sure since I havent seen those anywhere else (btw I am just 2 years out of the school). Both power supplies are external. Rack 1 is full 16 slot chassis with 4 i/o groups used, and rack 2 is a half of the rack.

Ctrl LGX
It has 6 slot chassis with PLC in slot 0, Ethernet card in 1, and RIO card in local slot 2.

The problem is when I take the old RIO card out, and set the dip switches in the rack 1 chassis
1 off - Outputs deenergized
2 on - Chassis restart
3 and 4 - (always)off (these are ON in the current plc2 setup)
5 off - 2 slot addressing (this one is on as well in the current)
6 and 7 - always off
8 off - highest numbered i/o present in this rack

and then set the RIO card (1771/A) for the baud rate (57.6) and rack number (11 and later 0) for the values I need, I can not get the proper communication between RIO module and the chassis. Either all lights are dead, or ACTIVE and ADAPTER FAULT are both on, and the RIO manual does not say anything about that specific signal.

So any help would be really appreciated, sine I am not sure if there is some incompatibility between different revisions of RIO modules and chassiss or something else as well.

I want to add that i was hooking up Ctrl Lgx PLC as well but no communication.

Also I would like to know how come that chassis backplane switches 3 and 4 are ON (when manual says always off), and the switch 5 is set for single slot addressing, when the addressing is in fact 2-slot (even with only first 4 groups populated with input cards). I did not spend much time with PLC connected until I resolve this problem first.

Thanks in advance,

Darko

To determine how to accomplish this migration you will have to provide the following information:

1. What model of PLC-2 controller are you using ? Is it a "Mini-PLC2" like the PLC-2/05 or 2/16 that fits in a chassis with the I/O modules? Or is it the larger PLC-2/20 or PLC-2/30 that have all the I/O modules remote from the controller ?

2. What is the part number of the power supply module on Rack 1 and Rack 2 ?

3. What is the part number of the adapter module (Slot 0) in Rack 1 and Rack 2 ? It is probably a 1771-AL Local I/O adapter if it says "PLC-2 I/O Adapter" on the front.

4. Describe the cable between the controller and the chassis. What color ? How thick ? How many conductors ? Is the port labeled ?

Are you replacing an older adapter with a new RIO adapter ? What is the full part number of the new RIO adapter ? 1771-ASB is the usual adapter, but you need to know for certain so you can set up the DIP switches correctly.

More information and details leads to better troubleshooting.

For your own research, have a look at the PLC-2 system conversion document in the RA Knowledgebase, Article ID #16474. PLC-2 support is all contract-based now so you do need a Tech Connect contract to view the support articles. Literature is still free.

Since it is almost end of the shift now, and I have just seen this reply, I will post data out of my head as follows:

1. What model of PLC-2 controller are you using ? Is it a "Mini-PLC2" like the PLC-2/05 or 2/16 that fits in a chassis with the I/O modules? Or is it the larger PLC-2/20 or PLC-2/30 that have all the I/O modules remote from the controller ?
...

It is definetely one of the big ones. It stands by it self with its own power supply, memory module, battery power, and plc card. The power supply has 2 different voltages (we had problem last week).

______________
2. What is the part number of the power supply module on Rack 1 and Rack 2 ?
...
Not sure right now, but will find out tomorrow. They are external and adjacent to chassis and i think we are using those in some of our PLC5/40 rio racks.

______________
3. What is the part number of the adapter module (Slot 0) in Rack 1 and Rack 2 ? It is probably a 1771-AL Local I/O adapter if it says "PLC-2 I/O Adapter" on the front.
...
It does say PLC-2 I/O adapter on the front, and they have 2 of the connaction ports (really similar to the old parallel printer ports)

______________
4. Describe the cable between the controller and the chassis. What color ? How thick ? How many conductors ? Is the port labeled ?
...
Really thick, gray, no idea how many conductors, since there is this (parallel port) connector on each end of the cable. I can count the pins though.
______________
Are you replacing an older adapter with a new RIO adapter ? What is the full part number of the new RIO adapter ? 1771-ASB is the usual adapter, but you need to know for certain so you can set up the DIP switches correctly.

Yes, I am planning to replace those old ones with the ones that work with PLC5 (which would be 1771-ASB/series A,B or C) since we have those in stock, and I already set parameters of the 1756 DHRIO/D card.
______________
More information and details leads to better troubleshooting.

For your own research, have a look at the PLC-2 system conversion document in the RA Knowledgebase, Article ID #16474. PLC-2 support is all contract-based now so you do need a Tech Connect contract to view the support articles. Literature is still free.

Thanks for the recomended article. I need as much of ideas so I can try as many options and holpfully get this thing running this following thursday.

Ok, our PLC model is 2/20, chassis part number where it is stored: 1772-LP1.
One rack is powered from this chassis and second one has its own power supply. This power supply part number is/should be: 1771-P2
I was not able to get a part number of ASB module since it is in use right now, but it does have "PLC-2 IO Adapter" in front.
Communication cable that these 2 racks and PLC connected has 1777-CA on it. Gray, thick cable with huge connectors on ends.
Remote IO adapter I am planning on using would be either 1771-ASB, or 1771-ASC.
Thanks,

Darko

darkesha said:

I was not able to get a part number of ASB module since it is in use right now, but it does have "PLC-2 IO Adapter" in front.
Communication cable that these 2 racks and PLC connected has 1777-CA on it. Gray, thick cable with huge connectors on ends.

Click to expand...

These are definitely 1771-AL local I/O adapters. They use parallel data transfer. The chassis dip switches have different functions for these adapters vs. the ASB's

darkesha said:

Remote IO adapter I am planning on using would be either 1771-ASB, or 1771-ASC.

Click to expand...

These part numbers are confusing.
In the beginning, there was the 1771-AS. This part was an assembly consisting of the 1771-ASC (the module) and the 1771-W? wiring arm. Later, an improved version was released called 1771-AS series B, often referred to as 1771-AS/B, and later still as just 1771-ASB. More recent versions add to the confusion, being called 1771-ASB series C or D.

Rack part #

On some older PLC 2 racks the ASB modules will not work. Make sure it is A4B rack type. Even so I've had to replace some of these racks. By my experience, replace the racks. On the ASB module, Sw 2 is the only one that should be on. The slot addressing was 2 slot for the PLc-2. Make sure you test the install before rewiring the cabinet. Dont pull the PLC 2 till you have a working system,and the managers are happy.

The reason i mention both is because I have just checked the stock, and I could see we stock both kinds.
However, with 2 modules 1771-ASB series A and C I was not able to get proper communication to one rack (where I tried upper or rack 1), and I was following Allan Bradley manual for RIO adapters.
I tried to set the Chassis Backplane switches in this manner:
1 - off
2 - off or on
3 - off
4 - off (3 and 4 always off)
5 - off
6 - off (5 & 6 for 2 slot addressing)
7 - off
8 - off (7 & 8 always off)

Also RIO adapter dip switches were in this position:

Switch 1
1 - 8 On

Switch 2
1 - on
2 - off (1 & 2 for 57.6K Baud)
3 - off (always off)
4 - off (to scan it all even last 5 slots were empty)
ASB modules I was trying out did not have 6 dip switces on switch 2.

Darn switches

On the Chassis, (A4B Chassis), SW 2 on, The rest off.
The ASB you have correct except on SW-1. SW 6 has to be off. On the right side of the Chassis a label should tell you the Model #, A2B, A3B or A4B.

No luck this thursday again.
This time I only tried second rack, since I had incompatible power supply to the rack 1 (power coming off PLC2/20 enclosure).
I tried two kinds of remote IO modules. One was 1771-ASC series A, and other one was 1771-ASB/E.
On ASC I would get active and adapter fault lights on, as soon as I apply power to the chassis, and without connecting wiring arm.
On ASB module I would get only adapter fault light on again with only applying power and wiring arm being disconnected.
Both chassis are 1771-AD series (It looks like AO since they are mounted all the way right to the end of the enclosure). So I am suspecting that this chassis are not compatible with RIO dip switches settings.
If someone has some other thought I really can not wait to hear/see it.
Thanks!

Darko

1771 - Ad

This chassis will not work with ASB modules. The red
dip switch bank runs left to right. You want the A4B chassis where the switch bank sits vertical.

Thanks, too bad that there are limits like this. I did hop it would be possible since manual that Ken posted link for has sentence like this: "When the 1771-A1...or 1771-AD I/O Chassis is retained and a 1771-P3,1771-P4, 1771-P4S...is to be installed, the following restrictions apply..."
Does this mean that if I switch 1771-P2 PSU and use internal PSU such is 1771-P4S in slot 0 and then rework logic around i would be possible to get it communicating or should I just go with new chassis ?

Or... you could convert the I/O to 1756, too. Then you wouldn't have to mess with it.

OZEE said:

Or... you could convert the I/O to 1756, too. Then you wouldn't have to mess with it.

Click to expand...

Well, I do not have much to say about decisions that will be made. I do keep the pleasure to present the options though.
Whats more important to me is backward compatibility of these A4B chassis and PLC 2 ASB modules curently in use ????
If I do switch chassis over, and for any reason I need to go back to PLC2 controller, does that meant that I will have to put the old chassis back in? Or the A4B chassis is compatible with 1771-AL modules???

I'm working from Knowbase article 16474, which says:

" Note that the 1771-P1, 1771-PA, 1771-P2, 1777-P2 and 1777-P4 Power Supplies can still be used to power 1771-AR, 1771-AS and 1771-ASB I/O Adapter Modules in remote chassis, all series of chassis supported. "

Time to go through the DIP switch settings to make sure I agree.

Plc-2

We left the P2 supplies in. The A4B will work with PLC-2 communication cards but I'm not sure of the dip sw settings. Ozee had a good idea, use the CLX rack and I/O. This means a lot of wiring changes but maybe somthing to think about. Also, How about just putting a PLC-5/40 in the first rack? Get this working then step up to the CLX processor after getting the communication working. You could write the program now and then next thurs swap the racks out, put A4B racks in, slide the processor in the first slot of rack #1, set the processor to using the first rack as rack #1, put the ASBs in the other racks, then get your program working. Even if you have to borrow a 5/40 for a couple months. Put the CLX remote I/O adapter on the data hiway and get that part working, then pull the 5/40 and slip in the last ASB module. Something to think about.