Mitsubishi Q Series Programming Guide

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4 SFC PROGRAM CONFIGURATION
MELSEC-Q
2) When the specified block is active:
If the step is already active when the SET instruction is executed, the step will remain
active and processing will continue, with another step being designated as active.
(Multiple step activation, follow-up function.)
Processing is performed as shown below when step 1 in block 1 is started in the
sequence program.
S0
S2
S1
Block 1: Active Block 1: Active
When step 1 (S1)
is started
S0
S2
S1
Multiple steps active
(Follow-up function)
Active
Inactive
Active
Inactive to active
(b) When multiple initial steps exist, an initial step selection START will occur when a given
step is specified and activated.
(c) When designating a step located in a parallel branch, all the parallel steps should be
activated. An inactive parallel branch ladder at such a time will prevent the parallel coupling
condition from being satisfied.
(d) If a specified step is already active when this instruction is executed, the instruction will be
ignored (equivalent to the NOP instruction), and processing will continue.
To hold a specified step with the HOLD step, see "Transition to HOLD step by double
START" in Section 4.7.6.
(e) When the operation output is used to start the step, do not specify the current step number
as the specified step number.
If the current step is designated as the specified step number, normal operation will not be
performed.
S0
S2
S1
sS1
(f) Specify the step as described below.
1) In the case of SFC program
• Use "Sn" when specifying the step in the current block.
• Use "BLm\Sn" when specifying the step in another block.
2) In the case of sequence program
• Use "BLm\Sn" when executing the step START instruction in the sequence program.
• When the block number is not specified, specify the block number with the BRSET
instruction.
However, the BRSET instruction cannot be used for the Basic model QCPU and
Universal model QCPU.
Block 0" is set when the block number is not specified for the Basic model QCPU and
Universal model QCPU.

Mitsubishi Q Series Specifications

General

I/O Points	Up to 4096 points
Communication	Ethernet, RS-232, RS-485
I/O Modules	Digital, Analog, Specialized
Programming Language	Function Block Diagram, Structured Text
Power Supply	24V DC, 100-240V AC
Operating Temperature	0°C to 55°C
Shock Resistance	147 m/s2 acceleration, 3 times in each of X, Y, and Z directions
Program Capacity	Up to 252K steps