Rockwell Automation SA500 Diagnostics, Troubleshooting Guide - Manual (Page 15)

Diagnostics and Troubleshooting 2-5
2.4.1.2 MCR Output Control
The MCR output on the Power Module is used to control an output contactor. This
output contactor, sometimes referred to as an M-contactor, disconnects power from
the motor. This option is selected during UDC module parameter configuration. If the
programmer selects to connect the MCR output to an output contactor, auxiliary
contacts from this device must be wired to the AUX IN1/MFDBK input as feedback.
The PMI operating system will wait for AUX IN1/MFDBK to turn on before executing
any operating mode.
The Run Permissive input (RPI) on the Power Module and the MCR output are
interlocked in hardware. The MCR output can be turned on only when the RPI is
asserted. The MCR output itself is under the control of the PMI. Application tasks
have no direct control of the MCR output. RPI is controlled by the user. When RPI is
off, MCR cannot be activated.
The following conditions will cause the MCR output to turn off:
• Absence of the RPI signal
• Occurrence of a drive fault
• Control algorithm is turned off (PMI_RUN@ = 0)
When any of the above conditions occurs, the PMI will disable the power device gates
and the motor will begin a coast-to-rest stop. The PMI will wait 100 msec and then turn
off the MCR output.
In addition, if the RPI signal is removed, the MCR output and gate power will be
removed under hardware control within approximately 0.5 seconds of the removal of
the RPI signal to provide an additional interlock. This is done regardless of the actions
taken by the PMI.
2.4.2 Drive Warnings
The PMI will check for conditions that are not serious enough to shut down the drive,
but may affect its performance. If the PMI detects any of the conditions described in
the Drive Warning register, it will set the appropriate bit but will NOT shut down the
drive. The user must ensure that the application task tests the Drive Warning register
(203/1203) and takes any appropriate action if a warning condition is detected.
The PMI will also set the Warning Detected bit (register 200/1200, bit 9, WRN@) if a
drive warning has been detected.
Appendix B provides a complete description of the Drive Warning register. Except for
rail faults, drive warnings are not indicated by LEDs (a rail fault will turn on the RAIL
FLT LED on the Power Module).
Drive warnings are not displayed in the UDC task's
error log.