Mitsubishi Electric MELSEC-Q00U(J)CPU User Manual page 566

Number
*1
Power supply off detection flag
SM1780
*1
Power supply failure detection flag
SM1781
*1
Momentary power failure detection flag for power supply 1
SM1782
*1
Momentary power failure detection flag for power supply 2
SM1783
*1 The special relay can be used if the serial number (first five digits) of the Universal model QCPU is "10042" or later.
564
Name/Description Measures
The Universal model QCPU does not store redundant
power supply system information in SM1780 to
SM1783. Delete the corresponding sections. (SM1780
to SM1783 are always off.)