Chapter 3. CPU Configuration
GFK-2222AD
April 2018
123
3.2.7
Fault Parameters
You can configure each fault action to be either diagnostic or fatal.
A
diagnostic fault
does not stop the PLC from executing logic. It sets a diagnostic variable and is
logged in a fault table.
A
fatal fault
transitions the PLC to the Stop Faulted mode. It also sets a diagnostic variable and is
logged in a fault table.
Fault Parameters
Loss of or Missing
Rack
(Fault group 1.) When BRM failure or loss of power loses a rack or when a configured rack
is
missing,
system
variable
#LOS_RCK
(%SA12)
turns
ON.
(To turn it OFF, fix the hardware problem and cycle power on the rack.)
Default: Diagnostic.
Loss of or Missing
I/O Controller
(Fault group 2.) When a Bus Controller stops communicating with the PLC or when a
configured Bus Controller is missing, system variable #LOS_IOC (%SA13) turns ON.
(To turn it OFF, replace the module and cycle power on the rack containing the module.)
Default: Diagnostic.
Loss of or Missing
I/O Module
(Fault group 3.) When an I/O module stops communicating with the PLC CPU or a
configured module is missing, system variable #LOS_IOM (%SA14) turns ON.
(To turn it OFF, replace the module and cycle power on the rack containing the module.)
Default: Diagnostic.
Loss of or Missing
Option Module
(Fault group 4.) When an option module stops communicating with the PLC CPU or a
configured option module is missing, system variable #LOS_SIO (%SA15) turns ON.
(To turn it OFF, replace the module and cycle power on the rack containing the module.)
Default: Diagnostic.
System Bus Error
(Fault group 12.) When a bus error occurs on the backplane, system variable #SBUS_ER
(%SA32)
turns
ON.
(To turn it OFF, cycle power on the main rack.)
Default: Fatal.
I/O Controller or
I/O Bus Fault
(Fault group 9.) When a Bus Controller reports a bus fault, a global memory fault, or an
IOC
hardware
fault,
system
variable
#IOC_FLT
(%SA22)
turns
ON.
(To turn it OFF, cycle power on the rack containing the module when the configuration
matches the hardware after a download.)
Default: Diagnostic.
System
Configuration
Mismatch
(Fault group 11.) When a configuration mismatch is detected during system power-up or
during a download of the configuration, system variable #CFG_MM (%SA9) turns ON.
(To turn it OFF, power up the PLC when no mismatches are present or download a
configuration that matches the hardware.)
This parameter determines the fault action when the CPU is
not running.
If a system
configuration mismatch occurs when the CPU is in RUN Mode, the fault action will be
Diagnostic. This prevents the running CPU from going to STOP/FAULT mode. To override
this behavior, see
Configuring the CPU to Stop Upon the Loss of a Critical Module
Default: Fatal.
Fan Kit Failure
(Fault group 0x17.) When a fault is detected in the Smart Fan kit, system variable
#FAN_FLT (%SA7) turns ON.
(To turn a fan kit fault OFF, clear the Controller fault table or reset the PLC.)
Default: Diagnostic.
