Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 36

■ Restrictions for module function blocks
The following describes the restrictions for the use of module function blocks.
• Do not turn off the contact of the MC instruction when calling a module function block between the MC instruction and MCR
instruction.
• Do not perform the jump processing that prevents module function blocks from being called by the CJ instruction, SCJ
instruction, and JMP instruction.
• Execute a subroutine program every scan when calling a module function block in the subroutine program. Do not perform
the non-execution processing of a subroutine program by using the FCALL(P) instruction, EFCALL(P) instruction, or
XCALL instruction.
• Do not call a module function block in an interrupt program or event execution type program.
• Do not call a module function block between the FOR and NEXT instructions, in the inline ST, or the control syntax of the
structured text language (IF statement, FOR statement, and CASE statement.)
• Do not use the program control instructions (PSTOP(P) instruction, POFF(P) instruction, and PSCAN(P) instruction) to the
program that calls a module function block.
■ When the CPU module that controls the target module of a module function block is changed
The module function block used in the program will be deleted if the CPU module set to "Control PLC Settings" of "I/O
Assignment" in system parameters is changed to another CPU module.
Copy the program into the project of another CPU module before changing the parameter setting.
■ Changing operating parameters of module function blocks
Operating parameters (external variables) other than input and output labels of module function blocks can be changed on the
label setting window by using the engineering tool.
• When the instance of a module function block is set to local label, change the parameters on the "Local Label Setting"
window.
[Project view]  [Program]  execution type  program file  program block  [Local Label]
• When the instance of a module function block is set to global label, change the parameters on the "Global Label Setting"
window.
[Project view]  [Label]  [Global Label]
3 PROGRAM ORGANIZATION UNITS
34
3.4 Precautions