Remote I/o Not Controlling Outputs

Hello:



I’m trying to get a Remote I/O Adapter (1771-ASB Series B) to communicate with a PLC 5/11 (Channel 1a). The PLC is connected (through Channel 0) directly to a PC running RSLinx/RSLogix software. I also tried to use a 6200 terminal (old school windows program / DOS based program)



My problem is I cannot get the Software to recognize the outputs in the Remote I/O chassis. It recognizes the inputs (of the remote I/O) and I can write programs involving the inputs but I cannot force the outputs to go on and I cannot program them to go on. I tried switching the PLC 5/11 and the RIO adapter but the problem followed. I could see all inputs and outputs on the chassis with the Processor but I can only see the inputs on the RIO chassis – outputs don’t work. I’m sure that the output cards are functional because when I switched the RIO and the Processor they worked perfectly when in the chassis with the processor.



Also, the light on the output card that indicates the outputs are energized will not light.



I’ve been working on this thing for a week and I cannot figure it out.



I’m an intern working for this company and I didn’t even know what a PLC was a few weeks ago. I had some help from the process engineers here but with their knowledge we still couldn’t figure it out.



Thanks for taking the time out to read my post, and double thanks to those of you who respond!

can you ZIP and post your .RSP file? ... also tell us how ALL (repeat ALL) of the DIP switches are set on the ASB - and on the backplane of the PLC chassis - and on the backplane of the Remote chassis ...

also ... it would be VERY helpful to know what modules (catalog numbers, please) are located in the various slots ... and the number of slots in each chassis ...

survival tip: do not "number" the slots in your description ... instead use "letters" A-B-C, etc. ... that way the "one-slot, two-slot, half-slot" addressing modes won't throw you off ...

we can help you nail this down - but one little DIP switch in the "wrong" position can keep the system from working ...

the more we know about your system, the more detailed help we can provide ...

and incidentally, you should be aware that the Remote chassis MUST be set up as "Rack 3" when using a PLC-5/11 ... (secret handshake: PLC-5/11 is not as flexible as most other processors when it comes to Remote I/O) ...

and welcome to the forum ...

I'll give Ron some credit here, it looks like the dip switches regarding outputs may be askew...

Another thought is that the addressing you are using is incorrect. AB 1771 IO is configured by location. If you have, say, an "IB" input modules in the first two slots (group 1), you would want to use "OB" modules in the next two slots group 2).

HOWEVER - you have to address it in the program by its physical address. You will have "I:30" and "O:30" in your data table, but "O:30" can't be used! The addressing in the example I used would have addresses for outputs beginning in "O:31/00". I can see how this could be missed on an AB PLC system.

Inputs:

   CPU |      IB IB      |     OB OB     | 

       I:30/0-17      O:31/0-17

  

*stupid corrections made, because I are missing stuff...

Greetings Tom ...



unless I’m mistaken (that’s happened before) the PLC-5/11 can ONLY use “Rack 03” for Remote I/O assignments ...



so ...



all of the digital/discrete addresses in the Remote I/O chassis MUST fall into the range:



I:030/0 thru I:030/17 ... or ... O:030/0 thru O:030/17 for the module located in the first physical slot in the RIO chassis (assuming that the ASB adapter's DIP switches are set up to use the first "group" in "Rack 03") ...



and then we would continue counting on from there ... we can’t say exactly how we would continue the counting until we nail down whether the RIO chassis is using the “two-slot” or “one-slot” or “half-slot” addressing mode ... and we can’t tell THAT until we know how the DIP switches are set on the backplane of the RIO chassis ... and ... if the DIP switches on the backplane of the LOCAL chassis are set for “half-slot” mode - AND if that local chassis is a sixteen slot size, then all four of the processor’s available “racks” (Rack 00 through Rack 03) will already be used up by the local chassis - and the RIO chassis can’t be used at all ...



so basically, we need to know a LOT more about this system in order to proceed ...

Ooops, I haven't worked on a 5/11, and I DID READ where you said "Rack 3". My mistake. Same scenario applies, but you are correct, there's more info required.

Okay, wow, I didn't expect so many replys so quickly, amazing.
I'm not sure about getting that .RSP file uploaded because that computer's floppy drive doesnt work and i'm not sure if the USB drives work or not. I'll
find out and post it later if I can.
Okay, here we go:
PLC 5/11 PROCESSOR CHASSIS
SLOTS ARE LABELED A-H FROM LEFT TO RIGHT.

A) 1771-IB (12-24V) DC INPUT MODULE
B) 1771-IB (12-24V) DC INPUT MODULE
C) 1771-OB (12-24V) DC OUTPUT MODULE
D) 1771-OB (12-24V) DC OUTPUT MODULE
E) 1771-IA (120V) AC INPUT MODULE
F) 1771-IA (120V) AC INPUT MODULE
G) 1771-OA (120V) AC OUTPUT MODULE
H) 1771-OA (120V) AC OUTPUT MODULE
Each of the above cards have only 8 Input OR Output contacts (0-7) & everything in tha Chassis works fine.

Proc DIPs:
s1:
1 - on
2 - on
3 - on
4 - on
5 - on
6 - on
7 - off
S2:
1 - on
2 - on
3 - on
4 - off
5 - off
6 - on
7 - on
8 - off
9 - on
10 - off

PROC BackPlane
1 - off
2 - off
3 - off
4 - off
5 - off
6 - on
7 - off
8 - off


REMOTE I/O ADAPTER MODULE CHASSIS
SLOTS ARE LABELED A-H FROM LEFT TO RIGHT.
A) 1771-IADB (120V AC/DC) INPUT MODULE
B) 1771-OD16A (120V) ISOLATED AC OUTPUT MODULE
C) EMPTY
D) EMPTY
E) EMPTY
F) EMPTY
G) EMPTY
H) EMPTY
The input card (slot A) has 16 inputs (00-17 octal)
The output card (slot B) has 16 outputs (00-17 octal) and it's fuses are all fine.
RIO DIPs:
sw1:
1 - on
2 - on
3 - on
4 - on
5 - off
6 - off
7 - on
8 - on
sw2
1 - on
2 - off
3 - off
4 - off
RIO Chassis Backplane DIPs
1 - off
2 - off
3 - off
4 - off
5 - on
6 - on
7 - off
8 - off

AND RON:
I shared your 2-b or not 2-b thing with some of the guys here and they loved it. they all got a kick out of it.

Greetings mholt ...







sorry I don't have time to dig through this completely - but in the meantime, try this:



on the RIO chassis backplane switch, set these changes



2 = ON (read safety note below)



5 = OFF



6 = OFF



if I'm guessing right, that will give you two-slot addressing in your RIO chassis (which should be consistent with your local chassis) ...



the input module should have the following addresses:

I:030/0 through I:030/17 ...



the output module should have the following addresses:

O:030/0 through O:030/17 ...



note that this conflicts with what my colleague tomalbright posted - but I still think that I’m right ...



SAFETY NOTE: that Switch 2 setting allows the processor to “restart” the chassis (after a fault, etc.) ... you have it set for “Lockout” which means you need a manually operated switch (etc.) wired to the ASB’s swingarm in order to “get things going” ... I’d bet (pocket change only) that’s the problem that’s keeping you from driving the outputs in that chassis ...



disclaimer: all of this is “best guess from where I sit” type stuff ... we need to see that .RSP program to finally nail everything down ...



see if this helps ... good luck with your project ...

All right Mr. Ron Beaufort!!
Excellent work. Apparently the RIO Chassis has to have the same kind of addressing as the Main Chassis.

I had a button wired to the arm and I used it liberally in case that was the problem, I didn't know that you could use switch 2 to bypass the button. In the manual I have it says that switch 2 and 3 are always off. But I tried what you said and vualla, works like you never new there was a problem.

You solved in about 20 minutes what I couldn't over a couple of weeks.

Again, thanks a lot!!

Excellent work.

Click to expand...

sometimes I get lucky ...

Apparently the RIO Chassis has to have the same kind of addressing as the Main Chassis.

Click to expand...

that is incorrect ... specifically, you CAN have a different addressing mode from chassis to chassis ... I just did it that way to keep things consistent ... it makes it easier for technicians who have to go from one chassis to another ...

I had a button wired to the arm and I used it liberally in case that was the problem, I didn't know that you could use switch 2 to bypass the button.

Click to expand...

please carefully consider the safety aspects of that setup ... you might need to go back to the “lockout” mode in order to make the system “fail safe” ... most systems do NOT use the “lockout” mode - but if that’s what YOUR system needs, then by all means put it back in place ... the only reason that I mentioned using the switch to “bypass” the lockout was to get you going - in case you did NOT have the button wired up ...

In the manual I have it says that switch 2 and 3 are always off.

Click to expand...

chances are that you’ve been looking at the manual for the PROCESSOR and not the one for the REMOTE I/O ADAPTER (ASB) ... compare the two books and you’ll see that the function of the DIP switches on the chassis backplane actually SHIFT when a processor is replaced by an adapter ... (GOTCHA! ... how’s THAT for consistency?) ... I actually helped troubleshoot a system once that the installers had “messed up” with that same mistake ... they didn’t have the manual handy for the ASB adapter they were installing - so they used the settings from the processor manual ... (incidentally, I mention that particular episode in every class while we're covering addressing) ...

But I tried what you said and vualla, works like you never new there was a problem. You solved in about 20 minutes what I couldn't over a couple of weeks.

Click to expand...

never underestimate the advantage of age and experience ...

Again, thanks a lot!!

Click to expand...

glad to help ... and thank Phil for the forum ...

that is correct.
I don't have a copy of the manual for the remote I/O adapter. I couldn't find one online and my employer didn't have a copy. do you happen to have an electronic copy?

how devious of Allen Bradley, shifting the functions of the backplane DIP switches...

also, who is phil and how do I thank him?

mholt said:

that is correct.
I don't have a copy of the manual for the remote I/O adapter. I couldn't find one online and my employer didn't have a copy. do you happen to have an electronic copy?

how devious of Allen Bradley, shifting the functions of the backplane DIP switches...

also, who is phil and how do I thank him?

Click to expand...

Per your request, see link below.

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1771-um001_-en-p.pdf

Phil Melore. Is PLCS.NET

http://www.plctalk.net/qanda/member.php?find=lastposter&t=38786

I see that my distinguished colleague Mickey has already posted a link to the ASB manual ... notice that this is for the “Series E” style - but the older series are covered in an appendix near the end...



you can find things like this at www.ab.com ... look under the “Literature Library” and do a search for the catalog number (example: 1771-ASB) ...








Phil Melore is the kind and benevolent webmaster who makes this excellent and free forum possible ...

Ron Beaufort said:

the input module should have the following addresses:

I:030/0 through I:030/17 ...



the output module should have the following addresses:

O:030/0 through O:030/17 ...



note that this conflicts with what my colleague tomalbright posted - but I still think that I’m right ...

Click to expand...

Nope. Take a look in the "Classic 1785 PLC-5 Programmable Controllers Users Manual Page 4-13". That's the complementary addressing table for 2-slot addressing. Unless you are doing complementary addressing with a second chassis, you use up the module space for both "I" and "O" addresses in a module group. While the manual doesn't exactly explain the addressing, the chart shows that it is there and how it is used.

(There's a LOT of AB manuals on 1771 products... they really need to index them.)

for clarification:

The addresses for the input card are I:030/0-17
The addresses for the output card are O:030/0-17

I was programming on it not to long ago and that is how they are addressed.

Try the outputs numbered by group address... Use beginning addresses I:030/00 for the first module, I:030/07 for the second, and O:031/00 for the third, etc.

You WERE setting an output bit with O:030/00, but the 1771 IO is setting it to an output module position in the first group, not the second. Since that one is an input module you saw no changes on your output.

Take a look at the pdf file I linked to, above. It gives some basic installation instructions on setting up a PLC5. Like I noticed, though, I don't think it describes the IO in detail, but it is shown in the figures. There's no way to set up the IO any different on a 1771 chassis. There's other configurations, but your main chassis is at the most basic level, two slot addressing.

Now, you're remote chassis is 16 bit modules, which you CAN set for either one slot or two slot addressing. In this case, you can use the same addressing for both modules, IF you configure the chassis as a 2 slot as well. The IO modules act as if they are in the whole group, both slots, and work properly. Actually, this may be what Ron had in mind; if you configure this way, you would have to have 2 slot addressing, and alternate your modules, IOIOIO... That way, you will "double fill" your chassis, legally.

Does that make any sense? And Ron, you were half right...