HELP!!! Can't Get 1771-OBD Modules To Go "Active"

[bkstump]

Yes! You're right. A 5/20 is only capable of 4 racks. And the 2nd rack (rack 3) is a 12-slot rack. The ASB is only reporting (after Auto Config) a rack size of 8 slots (030-037), yet the I/O Configuration has set the chassis size to 12 slots, and interprets the address space as 030-043.

Not sure if this would affect the ASB, but I'll check it out.

Thanks,
jim

 

[OkiePC]

EDIT: Nevermind this:

I dont think it can go past logical rack 3.

0-3 is four logical racks, ending at the eighth slot of your added chassis (037). To get 040-043, that would be half of a fifth logical rack, right?

Have you modified the IO status file? That may be required to get the Autoconfigure I/O to work correctly. I can't explain why it shows 030-043, except that it may be RSLogix figures you're looking at and not what the PLC believes is there.

Look at the values in the IOstat file directly to see if they match up with what the configuration screen shows you in RSLogix.

You don't care about the last four slots, so it should work.

How is the adapter reset configured? You may need to reset the rack, or configure it for auto-reset there and in the PLC.

 

[OkiePC]

EDIT:Wrong manual sorry...

Look in the 1771-ASB book for "Processor Restart Lockout."

When comms fail you have to configure what happens next on a chassis by chassis basis.

You can require a hardwired reset at the adapter, or let the PLC5/20E automatically reset the chassis.

 

[Ken Roach]

Ooh, shame on me for misremembering.

PLC-5/20 addresses only 4 logical Racks.
PLC-5/30 addresses 8, PLC-5/40 addresses 16, PLC-5/60 and 5/80 addresses 24.

I *think* that because the 1771-ASB responded to Autoconfigure as a single 8-slot "Full Rack" that it is ignoring the last 4 slots.

Can you unplug the PanelView, set the 1771-ASB to Rack 2, and try the Autoconfigure again ?

The "I/O Configuration" windows in RSLogix 5 are really just for recordkeeping; the actual Scanlist is the only thing that matters.

 

[Gil47]

No. The code was added offline, then downloaded. I've just re-downloaded again, and still have the problem. One thing I'm not sure about...
In RsLogix 5's IO configuration screen, I've got "Chassis_2" config. fields set as follows:

I/O channel: "1B - <I/O Scanner>"
Chassis Type: "1771-A3B (12 slots)"
Adapter: "1771-ASB Series B"
Inh: not checked
Res: not checked
Rack Addressing: "1 slot"
Rack: "3"
Group: "0"
Span: "3/0 - 4/3"
Complementary: "NO"

Now, I originally did not have a "Chassis Type". Instead, under Channel Configuration, I did an Autoconfigure, which added the following to the Channel 1B listing:

Rack: 3
Group: 0
Size: FULL
Range: 030-037

Since the 3rd rack is RIO'd via a 1771-ASB, and since the AutoConfig added the 3rd rack to the list, I didn't have a second A3B chassis added to the IO Configuration table. So I added another chassis to the same line that contains the I/O Channel "1B - <I/O Scanner>" in the I/O configuration Chassis Table.

It's not clear that this is necessary, but if I DON'T add the chassis, I do not get the Chassis configuration screens that allows me to define what modules go in which slots.

I'm still not sure about this one. In any case, it doesn't seem to make a difference. I simply cannot make outputs in rack 3 "active".

Thanks,
Jim
--

From memory if you manually enter in the scan list, that rack 3 is an 8 slot rack, I believe it may work, you then must remember that the last 4 slots in the rack will never work any I/O, but it is Ok to have a power supply in slot 12

 

[Bob A.]

I just checked the specs and the 5/20 is good for 4 racks. The 5/30 jumps to 8 and the 5/40 jumps to 16.

I does appear that a 12 slot w/ Single Slot Addressing would overflow into an unsupported rack. Your layout appears to have the unsupported slots unused, but maybe there is still a conflict. I never ran into this situation this before. Maybe try an 8 slot chassis?

Also, in the small Quick Reference Handbook, a slow blinking "Active" Indicator on an ASB is described as "Remote Scanner not actively controlling I/O". The recommended action is "None - Fault should be cleared by I/O Scanner". I would take that to mean that the processor has a minor rack fault set in the status table.



Bob A.

 

[bkstump]

Ok,
Probably a "Duh" question, but...

How do I interpret IOSTAT and IOCONFIG files?

Thanks,
Jim
--

 

[OkiePC]

Go to the processor status dialog and look at the main tab.

There should be an item called IO Status (S:16).

The number there refers to a file number which will contain the actual information that is displayed when you look at RSLogix IO config data.

Note that this is optional, but requied if you want to use RSLogix to autocinfigure, so most likely, you have a value in there.

The file number that is pointed to by S:16 will hold all the bits and bytes that contain the reset, inhibit, and fault bits for each RIO rack.

Then, on your channel config page there is a similar entry for channel diagnostic file. Do the same thing there, choosing another unique file number for IO diagnostics.

This is where you can retireve detailed RIO link status information. You can find out when your channel is experience coms timeouts, failures, and retries in this file.

Note that these are both optional, but RSLogix5 depends on their existence to properly display the user friendly channel diagnostics and IO status pages. Using Autoconfigure to read the rack layout depends on these files being configured and of adequate size too.

I have documented the bytes and bits of importance at one time in the past so that I could use them in ladder logic to trigger alarms and controlled shutdown of a machine.

The manual "Enhanced and Ethernet PLC5 Programmable Controllers" has a chapter that details the exact locations of the bits that are used.

See chapter 6, pages 6-24 in that book (Publication 1785-UM012D-EN-P - July 2005).