GSV instruction

[dshaffst]

I'm trying to dig to the source of a minor "recoverable" system fault throwing a fault light on a machine that has been confusing my operator because there's no apparent fault inhibiting operations. Thus far I've traced the fault to a bit tied to a GSV (Get System Value) instruction that's pulling it's number from "ControllerDevice" (selected as the Class Name). The number given right now is 12640 and this triggered fault is tied to the 9th bit in that number.

I've scoured the web for what this "ControllerDevice" number means and where in the PLC is generating it. Any ideas what ControllerDevice is pointing to? Is it hardware related? Where might this 12640 number be coming from?

Line 13, the bit being triggered. Ignore the "DS_TOGGLE_BIT". I just stuck that in there as a troubleshooting measure to see if this was the only thing behind the cabinet fault light and not something else.

 

[arpus4KM]

controllerdevice is just indicating that the device it's getting values from is the controller, if you edit the rung or make a new GSV, you can see in the dropdown all the selections available.

Furthermore, right click and hit instruction help. scroll down and look under 'GSV/SSV Object'

Inside there, you will see ControllerDevice, click on it and you'll get a list of what different things you can get out of the controller using the GSV instruction.

You are getting status back, so this is the list you can get from status bits.

Status INT GSV

Device Status Bits

7...4 Meaning

0000 Reserved

0001 Flash update in progress

0010 Reserved

0011 Reserved

0100 Flash is bad

0101 Faulted modes

0110 Run

0111 Program



Fault Status Bits

11...8 Meaning

0001 Recoverable minor fault

0010 Unrecoverable minor fault

0100 Recoverable major fault

1000 Unrecoverable major fault



Controller Status Bits

13...12 Meaning

01 Keyswitch in run

10 Keyswitch in program

11 Keyswitch in remote

15...14 Meaning

01 Controller is changing modes

10 Debug mode if controller in run mode

From your screenshot, Bits 5 and 6 are set. indicating it's in RUN Mode

Bit 8 is set, indicating recoverable minor fault

Bits 12 and 13 set, so it's key is in remote position









You are pretty much just seeing in that rung that the minor fault bit is turned on.

Go to your controller properties and look at the current error code and error listed for the minor fault and post it here.

 

[joseph_e2]

If you hit "F1" while the GSV instruction is selected, it will bring up the online help. Scroll to the end and pick "GSV/SSV Objects", then scroll down to "ControllerDevice". There's a table that shows Status as an INT tag with status bits:

7...4 Meaning
0000 Reserved
0001 Flash update in progress
0010 Reserved
0011 Reserved
0100 Flash is bad
0101 Faulted modes
0110 Run
0111 Program

Fault Status Bits
11...8 Meaning
0001 Recoverable minor fault
0010 Unrecoverable minor fault
0100 Recoverable major fault
1000 Unrecoverable major fault

Controller Status Bits
13...12 Meaning
01 Keyswitch in run
10 Keyswitch in program
11 Keyswitch in remote
15...14 Meaning
01 Controller is changing modes
10 Debug mode if controller in run mode

So bit 8 just means "Recoverable minor fault".
There are ways to access the minor fault code and I think there's a thread on here that covers fault routines that may be of some help if you can find it.

Edit:
Look at manual 1756-PM014. It suggests using a GSV to get the FaultLog object, MinorFaultBits attribute. The manual links to a spreadsheet with minor/major fault codes.

 

[drbitboy]

https://literature.rockwellautomation.com/idc/groups/literature/documents/rm/1756-rm003_-en-p.pdf#page=162

- Non-@OkiePC-safe link!