Omron cx-programmer 5.0-function block operation 사용자 설명서

When the input to the function block’s EN input variable is OFF, the function
block is not called, so the internal variables of the instance do not change (val-
ues are retained). In the same way the output variables do not change when
EN is OFF (values are retained).

!Caution An instance will not be executed while its EN input variable is OFF, so Differ-

entiation and Timer instructions will not be initialized while EN is OFF. If Differ-
entiation or Timer instructions are being used, use the Always ON Flag
(P_On) for the EN input condition and include the instruction’s input condition
within the function block definition.

A function block cannot be called from another function block, i.e., nesting is
not supported.

There are some restrictions on instructions used in ladder programs.

The following instructions cannot be used in function block definitions. A com-
pile error will occur if any of these instructions is used.

• Block Programming Instructions (All instructions, including BPRG and

BEND)

• Subroutine Instructions (SBS, GSBS, RET, MCRO, SBN, GSBN, and

GRET)

• Jump Instructions (JMP, CJP, CJPN, and JME)

• Step Instructions (STEP and SNXT)

• Immediate Refresh Instructions (!)

• I/O REFRESH Instruction (IORF)

• TMHH and TMHHX Instructions

• CV Address Conversion Instructions (FRMCV and TOCV)

FB

EN           ENO

1.0

P_Off

P_On

ENO

1.0

P_Off

P_On

Program

FB definition

Body

Execution results:
Output variable 1.0 is turned OFF, but 
internal variable a retains its previous value.

If the programming were entered 
directly into the program instead of in a
function block definition, both bit 1.0 
and variable a would be turned OFF.

Program

Internal 
variable a

Internal 
variable a

FB1

FB2

Program

Instance A

Instance A: FB1

Instance X: FB2