Mitsubishi Electric MELSEC iQ-R Series User Manual page 155

Redundant power supply system
The following table lists the special register areas relating to the system information. The information of the redundant power
supply system is stored.
All registers are turned off when the redundant power supply base unit is not used.
No. Name Description
SD150 Power-off/power Power-off/power
supply voltage drop supply voltage drop
detection status detection status
0: Power-on/normal
voltage
1: Power-off/voltage
drop detected/no
power supply
module
SD151 Power supply failure Power supply failure
detection status detection status
0: Not detected/
power-off/no power
supply module 1:
Detected
SD152 Momentary power Momentary power
failure detection failure detection
count (power supply count for power
module 1) supply module 1
SD153 Momentary power Momentary power
failure detection failure detection
count (power supply count for power
module 2) supply module 2
Details
• Power supply module status (power is shut off, power supply voltage
drop (not including a momentary power failure) is detected, or an
empty slot for the power-supply module exists) is stored using the
following bit pattern.
• When the main base unit is not the redundant power supply main base
unit, 0 is stored.
■Powered-off/power supply voltage drop detection status (power supply
module 1)
b0: Main base unit
b1: 1st extension base unit
b2: 2nd extension base unit

b7: 7th extension base unit
■Powered-off/power supply voltage drop detection status (power supply
module 2)
b8: Main base unit
b9: 1st extension base unit
b10: 2nd extension base unit

b15: 7th extension base unit
• The power supply module failure detection status is stored in the
following bit patterns.
• Bits corresponding to power-off or empty slots for the power supply
module turn off.
• When the main base unit is not the redundant power supply main base
unit, 0 is stored.
■Power supply failure detection status (power supply module 1)
b0: Main base unit
b1: 1st extension base unit
b2: 2nd extension base unit

b7: 7th extension base unit
■Power supply failure detection status (power supply module 2)
b8: Main base unit
b9: 1st extension base unit
b10: 2nd extension base unit

b15: 7th extension base unit
• This register counts the number of momentary power failures.
• This register monitors the status of the power supply module mounted
on the main base unit and counts the number of momentary power
failures.
• When the remote head module starts, the counter of the both power
supply modules is cleared to 0.
• When either of the power supply module is turned off, the counter of
the power supply module which is turned off is cleared to 0.
• The counter is incremented by one upon one momentary power failure
on each power supply. A counting cycle from 0 to 65535 to 0 is
repeated.
• When the main base unit is not the redundant power supply main base
unit, 0 is stored.
Set by (setting
timing)
S (Status change)
S (Status change)
S (Status change)
S (Status change)
Appendix 4 List of Special Register (SD) Areas
A
APPX
153