Calculating The Sfc Program Capacity; Method For Calculating The Sfc Program Capacity - Mitsubishi Electric MELSEC-Q Series Programming Manual

3.4

Calculating the SFC Program Capacity

In order to express the SFC diagram using instructions, the memory capacity shown below is required. The method for
calculating the SFC program capacity and the number of steps when the SFC diagram is expressed by SFC dedicated
instructions is described in this section.

Method for calculating the SFC program capacity

*1 Number of steps where SFC diagram is expressed by SFC dedicated instructions.
• Operation outputs for each step: The capacity per step is total number of sequence steps for all instructions.
For details regarding the number of sequence steps for each instruction, refer to the Programming Manual
(Common Instructions) for the CPU module used.
• Transition conditions: The capacity per transition condition is total number of sequence steps for all
instructions. For details regarding the number of sequence steps for each instruction, refer to the
Programming Manual (Common Instructions) for the CPU module used.
3 SPECIFICATIONS
36
3.4 Calculating the SFC Program Capacity
(1) Step
3 sequence steps for step START and END instructions
(2) Transition condition
: For serial transition or selective branching coupling
4 sequence steps for transition START instruction and transition destination instruction
: For parallel branching
Total number of steps for the transition START instruction, and transition destination instructions for the number of parallel
branches in question
: For parallel coupling
Total number of steps for the transition START instruction, and the transition destination instructions and coupling check
instructions for the number of parallel branchings in question -1.
(2) Jump, end step
Calculated as step 0 because it is included in the previous transition condition.