Allen Bradley SLC 500 fault

Hi All, I have had a lightning strike in my plant and my SLC 500 L551 is coming up with this error code (Illegal command N7.50+ or Illegal Commad N7.20+). Even after resetting the PLC the error code keeps appearing. Can anyone please help with this?

Cheers

Frank

What is the major error fault code ?
Does the PLC have a memory module (EPROM) ?

Jesper, thanks. I have only had this info since last night but here is all the info I have at this time:
Summary report on the trouble shooting of the PLC 6th April, 2011
Items
Details
Remarks
1

• Installed the Software on the Pc (Laptop), confirmed the R232 cable for communication with the processor
• Went through the downloaded PLC manual and documents

According to the Manual Flashing FLT light which is the case here signifies fault
2










Troubleshooting: Following the Manual instructions

• Checked all the fuses

• Toggled the processor key switch from Run to programme mode powered down and up again

• Pulled out the processor card and physically inspected

• Switched Jumper 4 from (on the processor) protected mode to Run mode, this cleared the flashing but not the fault.

Fuses Okay

No changes


Physical Inspection showed slot for back up flash memory is empty.

Fault not cleared
3

Findings:

• FLT Flashing indication on the Processor card

• Couldn’t establish communication with the processor either through the PLC display nor computer (PC).

Suspect Hardware (Processor ) faulty
4
Last Resort according to the manual

• Reset the Processor to factory

Implication

• This may clear the plant memory.
• Plant Code/Logic is needed

Further to this is the local guys report:
PLC Model AB- SLC 500
Processor model SLC 5/05

Operating system information

OS SER FRN
1747.OS501 C 11

CAT SER REV
1747-L551 C B

PROBLEM WITH THE PLANT.
The plant was operational and doing fine when heavy rain which was associated with Thunder and lightening started.
after one of the Thunders and lightenings which was visible hit the MCC build housing the PLC, the Plant tripped on ESD,
The display on the monitor says (COMMUNICATION ERROR)
The Global fire Alarm which was not implimented (Physically installed) but byepassed software wise lost its bye pass and was on alarm.

We tried Resetting using the Panel keys and switches, as usual, and each time we do this we get a message ( Illegal command N7.50+ or Illegal Commad N7.20+).

I am trying to get further info on this now and will update as soon as possible

Thanks again.
Frank

I think that the "Illegal command N7.50+ or Illegal Commad N7.20+" really refers to that the panel cannot see the addresses N7:50 and N7:20.
This could mean that the program is cleared. A cleared program would be consistent with a flashing FLT.

Does the PLC have a memory module (EEPROM) ?

What are the lights on the processor doing? Flashing, steady on, ...???

If you have EEPROM installed pull it out, cut the power to the processor and remove it from the processor from the rack. Now remove the battery and short the + and - terminals of the battey plug togeather for a few seconds, this will clear the processor.
Put it back in the rack, replace the EEPROM and turn it back on.
If the processor and all the modules are good it should power up re-losd from the EEPROM and be good to go.

let's start with this:

Hi All, I have had a lightning strike in my plant

Click to expand...

now then ...

(1) do you have RSLogix500 software loaded and available? ...
yes ...
no ...
I'm not sure ...

(2) do you have RSLinx software loaded and available? ...
yes ...
no ...
I'm not sure ...

(3) do you have a suitable null-modem cable connected between the DB9 serial port of your PLC processor – and a suitable serial port (or working adapter) on your computer? ...
yes ...
no ...
I'm not sure ...

(4) do you know how to configure the RSLinx driver to communicate with the PLC? ...
yes ...
no ...
I'm not sure ...

(5) can you get online (communicate) with the PLC? ...
yes ...
no ...
I'm not sure ...

(6) have you moved the J4 jumper on the processor's circuit board? ... (your post seems to indicate that you MIGHT have done this) ... that jumper needs to be in the PROTECT position ... see this link:
http://www.plctalk.net/qanda/showthread.php?p=135169&postcount=3

so - is the J4 jumper in the PROTECT position? ...
yes ...
no ...
I'm not sure ...

please answer these questions – and then we'll try to go from there ... but ... based on the fact that we have a reported LIGHTNING STRIKE to the system, we're going to be limited on what we can accomplish without going online with the processor – or at least confirming that we can NOT go online with the processor – and that we need a new one ...

Thanks to you all.

Jesper, the EPROM slot is empty! So no it does not have one. So if the program is reinstalled we could eliminate this cause?

OZEE, the light is flashing all the time.

Oldnerd. No EEPROM installed.

Ron, I will get back to you soon on your questions. We have no internet access at this time but trying to restore it now. Trying to get people to check things remotely here is difficult at anytime, but on Friday evening!!!!!!!!!!!!!!!!!!!!!!

This has been the most responsive forum I have ever been on to, and glad there are so many competent guys out there, thanks to you all.

Cheers

Frank

More.............

Also, the smoke detectors, and fire detector which ESD cases are all on alarm. If this is any further help to you all.

Cheers
Frank

We need to know what ALL of the lights are doing, not just fault light.

POWER
RUN
FORCE
FLT
BATT
ENET
RS232


If just the POWER is on and the FLT is flashing and all others are off, your processor lost the program and just needs to have the program downloaded.

Thanks

Ozee, great let me look into this and will get back to you guys.

Cheers

Frank

Ok Ozee, here are the lights status:

These are the status of the lights

Power - ON
RUN - OFF
FORCE - OFF
FLT - FLASHING RED LIGHT
BATT - OFF
ENET - FLASHING GREEN LIGHT. OFF WHEN YOU UNPLUG THE ETHERNET CABLE
RS232 - OFF

Cheers

Frank

Ron,
Here are the answers to the questions above:
1. We have the RSLogix 500 software loaded and activated for use.
2. We have the RSLinx software loaded and available.
3. We have it DB9 serial port cable linked to the computer via a usb to serial port cable.
4. For the configuration, let me list the steps we took to see if we are right.
a. Selected configure drivers from RSLinx software and selected RS-232 DF1 devices and clicked on add new tab. It loaded a driver named AB_DF1-1. I chose COM1 port ( reconfigured the usb port to com1), Selected device as SLC-CH0/Micro/PanelView, and changed the Error Checking to CRC. I left the others as the default.
b. I also tried to autoconfigure by clicking the auto-configure tab but it couldn’t communicate with the processor as it brought an error message.
c. I now opened the RS500 logix software and clicked on System comms. I now clicked on the driver AB_DF1-1 but I noticed a message “browsing – node 0 found, node 1 not found.”
d. Even when I click on upload or download, it tells me processor not found.
5. We can’t communicate with the PLC
6. We moved the J4 jumper from the protect position to the program position. The flt light stopped flashing but we couldn’t communicate with the PLC. We moved it back to the protect position and the FLT light resumed the flashing.
7. Yes the J4 jumper is in the protect position.

Cheers

Frank

The fact that you cannot "Auto-Configure" your DF-1 driver could indicate one of three things...

1. The processor is fried...

2. The processor serial port configuration is changed fron DF-1 protocol to User...

or

3. Your USB to serial convertor does not work (I have read that some work only if manually configured and that auto-configure does not work).

added : See picture 505 Channel1Defaults : set your DF-1 driver to that if you can't auto-configure with your USB adapter.

Recommendations...

a. Try a direct serial cable from a bona-fide RS-232 port on a PC or laptop. If you cannot auto-configure then go to b.

b. Try resetting the processor to factory default (which will restore the RS-232 port if corrupted), by shorting out the Batt + and - connections on the PCB pin connector, as described. However, this procedure is not mentioned in the manual for the 5/01 or 5/02 (Publication 1747-UM011G-EN-P - June 2008), so it may not be appropriate. Go back to a.

Just re-read - this is a 5/05 processor?
If YES, then reset to factory default by shorting VBB and GND lands on the PCB with a screwdriver (REMOVE BATTERY!). Manual recommends holding for 60 seconds!). See Picture "505 PCB"

c. Acquire another processor.

The J4 jumper should be left in the PROTECT position. It only prevents the firmware of the processor from being upgraded, which is not what you are trying to achieve.

Daba, thanks and will try this tomorrow and reply results soonest.

Cheers

Frank