Rockwell Automation GMLC Reference Manual - Manual (Page 544)

Publication GMLC-5.2 - November 1999
507
CPU Utilization Overrun Fault
The motion controllers continuously monitor average CPU utilization for
performance and safety purposes. A CPU utilization overrun
(Global_fault = 15) indicates that the average CPU utilization has
exceeded 90%. When a CPU utilization overrun fault occurs, the
controller:
• stops all motion on all axes
• disables feedback on all axes
• sets all servo outputs to zero
• deactivates all drive enables
• disables CPU Watchdog output
The occurrence of this type of fault indicates that the servo update rate is
set to a value that is too high to support the complexity of the application
running in the controller.
The motion controller displays the CPU Utilization Overrun fault in the
Terminal Window or the runtime display (if enabled). However, this fault
variable is not available in the Expression Builder.
Feedback Device Fault
The motion controllers periodically perform integrity checking of the
position feedback interface chips installed in the system. If any of these
chips fail one of the checks, a feedback device fault (Global_fault = 14)
indicates the device failure. If such a condition occurs,
Encoder_Loss_Fault (Resolver_Loss_Fault on the 1394 GMC/1394
GMC Turbo) is also indicated on the axes that are associated with the
failed device. A feedback device fault usually requires a service
replacement.
The motion controller displays the Feedback Device Fault in the Terminal
Window or the runtime display (if enabled). However, this fault variable
is not available in the Expression Builder.