Mitsubishi Electric MELSEC-Q Series Programming Manual page 95

Setting of Operation
Output Mode Output at
at Block Stop Block Stop
in PLC (SM325)
Parameter
Remains ON ON
(coil output held) (coil output held)
*1 The held step indicates the step whose attribute has been set to the HOLD step (SC, SE, ST) and which is being held with the transition
condition satisfied.
The operation of SM325 differs depending on the CPU module.
• For the Basic model QCPU, High Performance model QCPU, and Process CPU
SM325 turns ON/OFF according to the parameter setting (output mode setting at block stop) when the CPU
module is powered ON or is reset.
• For the Universal model QCPU and LCPU
SM325 turns ON/OFF according to the parameter setting (output mode setting at block stop) when the CPU
module is powered ON or is reset.
Turning OFF the output mode setting at block stop (coil output OFF): SM325 is OFF.
Turning ON the output mode setting at block stop (coil output held): SM325 is ON.
Note that the output mode at block stop can be changed regardless of the parameter setting by turning ON/
OFF SM325 in the user program.
• The STOP/RESTART bit switches ON when the SFC control "block STOP" instruction (PAUSE BLm) is executed.
■Block RESTART instruction (RSTART)
• The block in question is restarted from the step where a STOP occurred. An "operation HOLD status" step (with transition
check or without transition check) which has been stopped will be restarted with the operation HOLD status in effect. A "coil
output HOLD" step cannot be restarted after being stopped as it becomes deactivated at that time.
• Depending on the ON/OFF status of the "block STOP-time operation output flag (SM325)", the operations of the PLS
instruction and P instruction after block STOP cancellation change.
When SM325 is ON (coil output held): Not executed
When SM325 is OFF (coil output OFF): Executed again
• When the block STOP/RESTART bit of the SFC information devices has been set, the block STOP/RESTART bit also turns
OFF.
Status of Operation
STOP-time
Active step other than
Mode Bit
held step (including
HOLD step whose
transition condition is
not satisfied)
OFF or no • Immediately after a STOP
setting request is made, the block is
(immediate stopped with the coil output
stop) of the operation output being
held.
• The status remains active.
ON • Normal operation is
(STOP after performed until the transition
transition) condition is satisfied.
• When the transition
condition is satisfied, the end
processing of the
corresponding step is
performed. At the same
time, the transition
destination step becomes
active and the block is
stopped before execution of
the operation output.
4.4 Controlling SFC Programs by Instructions (SFC Control Instructions)
*1
Held step
Coil HOLD step Operation HOLD
(SC) step (without
transition check)
(SE)
• Immediately after a STOP request is made, the block is stopped
with the coil output of the operation output being held.
• The status remains active.
4 SFC PROGRAM CONFIGURATION
Operation HOLD
step (with
transition check)
(ST)
4
93