Restarting A Stopped Block - Mitsubishi Electric MELSEC-Q Series Programming Manual

Operation of SM325
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) at STOP RUN of the CPU
module.
■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.
Parameter setting
Turns OFF (coil output OFF)
Remain ON (coil output held)
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.

Restarting a stopped block

The methods for restarting a block which has been temporarily stopped during SFC program processing are described below.
Restarting block processing
The methods for restarting a block which has been temporarily stopped are shown below.
Restart Method
Restart by SFC control instruction
RESTART by SFC information device
Active step when restart occurs
The step which is active when a block is restarted varies according to the status which existed when the STOP occurred, as
shown below.
Output Mode Operation Output at Block RESTART
Setting at Block
Active step other than held step
STOP
(including HOLD step whose
transition condition is not
satisfied)
At coil output OFF Returns to normal operation.
At coil output HOLD
*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.
Operation of SM325
The operation of SM325 is the same as one of the block STOP methods. ( Page 163 Operation of SM325)
Operation Description
Processing of the specified block is restarted by an SFC
control instruction at a step (operation output) or
sequence program outside the stopped block.
The execution of the corresponding block is restarted by
forcibly turning OFF the "block STOP/RESTART bit",
which was set to each block as the SFC information
device, in the program or peripheral device.
Held step
Coil HOLD step (SC)
Restart disabled. (Since the
step is deactivated at a block
STOP)
Restarts as held.
SM325
OFF
ON
Remarks
Convenient for returning to automatic operation when the
manual control END signal is output at the temporary
STOP.
Convenient for confirming operation by step control at
debugging and test operations, because block
processing can be restarted from a peripheral device
without requiring a program.
*1
Operation HOLD step
(without transition
check) (SE)
Restarts the execution of
the operation output in a
HOLD status.
6 SFC PROGRAM EXECUTION
6.3 Block Temporary Stop and Restart Methods
6
Operation HOLD step
(with transition
check) (ST)
• Restarts the operation
output in a HOLD
status.
• Also checks the
transition condition.
163