Instruction manual

4. SERVO SYSTEM CPU DEVICES
4 − 40
4.3 Special Relays/Special Registers List
4.3.1 Special relays
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!
!!
!
Valid)
Device No. Signal Name
REAL VIRTUAL
Signal
Direction
Refresh Cycle Fetch Cycle
M9073 PCPU WDT error flag
M9074 PCPU READY completed flag
M9075 TEST mode ON flag
M9076
External emergency stop input
flag
M9077
Manual pulse generator axis
setting error flag
M9078 TEST mode request flag
M9079 Servo program setting error flag
!!
SCPU
←
PCPU END
(1) PCPU WDT error flag (M9073).........................Signal sent from PCPU to SCPU
This flag switches ON when a "watchdog timer error" is detected by the PCPU's
self- diagnosis function. When the PCPU detects a WDT error, it executes an
immediate stop without deceleration of the driven axes.
If the PCPU WDT error flag switches ON, press the servo system CPU's
[RESET] key to execute a reset.
If M9073 remains ON after a reset occurs, there is a PCPU malfunction. The
error cause is stored in the "PCPU WDT error cause (D9184)" storage area
(see Section 4.3.2 (2)).
(2) PCPU READY completed flag (M9074)............Signal sent from PCPU to SCPU
This flag is used to determine (at the sequence program) if the PCPU is normal
or abnormal.
(a) When the PLC READY flag (M2000) turns from OFF to ON, the fixed
parameters, servo parameters, limit switch output data, etc., are checked,
and if no error is detected the PCPU READY-completed flag comes ON.
The servo parameters are written to the servo amplifiers and the M-codes
are cleared.
(b) The PCPU READY flag switches OFF when the PLC READY (M2000)
signal switches OFF.
PLC READY
(M2000)
PCPU READY
completion
(M9074)
t
Servo parameters are written to the servo
amplifier, and M-codes are cleared.
(3) TEST mode ON flag (M9075) ...........................Signal sent from PCPU to SCPU
(a) This flag status indicates whether a TEST mode established from a
peripheral device is currently in effect. It can be used as an interlock
function when starting the servo program by a sequence program SVST
instruction.
• OFF................... TEST mode is not in effect.
• ON .................... TEST mode is in effect.
(b) If the TEST mode is not established in response to a TEST mode request
from a peripheral device, the "TEST mode request error flag (M9078)" will
switch ON.