Appendix3 Special Relays And Special Registers; Special Relays (Sp, M) - Mitsubishi Electric A173UHCPU Programming Manual

APPENDICES

APPENDIX3 SPECIAL RELAYS AND SPECIAL REGISTERS

3.1

Special Relays (SP, M)

Number Name
M9000
Fuse blown
(Note-1)
M9002
I/O unit verify error
(Note-1)
M9004 MINI link error
M9005
AC DOWN detection
(Note-1)
M9006 Battery low
M9007
Battery low latch
(Note-1)
M9008
Self-diagnostic error
(Note-1)
M9009 Annunciator detection
M9011
Operation error flag
(Note-1)
M9012 Carry flag
M9016 Data memory clear flag
M9017 Data memory clear flag
M9020 User timing clock No.0
M9021 User timing clock No.1
M9022 User timing clock No.2
M9023 User timing clock No.3
M9024 User timing clock No.4
The special relays are internal relays with fixed applications in the programmable
controller. Accordingly, they must not be turned ON and OFF in sequence
programs (those (Note-1) and (Note-2) in the table are exceptions).
Table 3.1 Special Relay List
Stored Data
OFF Normal
ON There is a module with a blown
fuse.
OFF Normal
ON Error
OFF Normal
ON Error
OFF AC DOWN detected
ON AC DOWN not detected
OFF Normal
ON Low battery voltage
OFF Normal
ON Low battery voltage
OFF No error
ON Error
OFF No F number detected
ON F number detected
OFF No error
ON Error
OFF Carry OFF
ON Carry ON
OFF No processing
ON Output cleared
OFF No processing
ON Output cleared
n2
scan scan
n1
scan
!
Comes ON even if there is only one output module with a blown fuse,
and remains ON even after return to normal.
!
Comes ON if there is a discrepancy between the actual I/O modules
and the registered information when the power is turned on.
!
Turns ON if there is an error-detected module at the master station of
MINI link. Remains ON if the module returns to normal.
! Comes ON when there is a momentary power interruption not
exceeding 20 ms; reset by turning the power OFF then ON again.
!
Comes ON when the battery voltage falls below the stipulated value;
goes OFF when normal battery voltage is re-established.
!
Comes ON when the battery voltage falls below the stipulated value;
remains ON even after normal battery voltage is re-established.
!
Comes ON when an error occurs as a result of self-diagnosis.
! Comes ON when OUT F, SET F instructions are executed.
Goes OFF when 0 is stored in D9124.
!
Comes on when an operation error occurs during execution of an
application instruction; remains ON even after the error is cleared.
!
Carry flag used in an application instruction.
!
When M9016 is ON, all data memory contents, including those in the
latch range but with the exception of special relays/registers, are
cleared on reception of remote RUN from a computer or other
device.
!
When M9017 is ON, all data memory contents that are not latched,
with the exception of special relays/registers, are cleared on
reception of remote RUN from a computer or other device.
! Relay repeats ON/OFF switching at fixed scan intervals.
!
Starts from the OFF status when the power is turned ON or on resetting.
n2
!
The ON/OFF intervals are set with the DUTY instruction.
APP − 38
Explanation
DUTY n1 n2 M9020