700
FX
3U
/FX
3UC
Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
31 Data Transfer 3 – FNC275 to FNC279
31.2 FNC279 – WBFM / Divided BFM Write
Explanation of function and operation
1. 16-bit operation (WBFM)
B From the buffer memory (BFM) location # "m2" in the special function block/unit No."m1", the amount of
memory specified by "n1" is transferred written to
in the PLC.
In transfering, "n1" is divided by "n2"(n1/n2 per 1 scan time, + 1 scan time when there is a remainder).
→
For the unit No., buffer memory (BFM) No., cautions, and program example,
refer to Subsection 31.1.1.
• When the instruction is finished normally, the instruction execution complete flag M8029 turns ON. When
the instruction is finished abnormally, the instruction execution abnormally complete flag M8329 turns ON.
• When RBFM (FNC278) or WBFM (FNC279) instruction in another step is executed for a same unit
number, the instruction non-execution flag M8328 is set to ON, and execution of such an instruction is
waited.
When execution of another target instruction is completed, the waiting status of an instruction is executed.
Related devices
→
For the flag use methods for instruction execution complete and instruction execution
abnormally complete, refer to Subsection 6.5.2.
Related instructions
Errors
An operation error is caused in the following case; The error flag M8067 turns ON, and the error code is
stored in D8067.
• When the unit number "m1" does not exist (error code: K6708)
Device
Name
Description
M8029
Instruction execution complete
Turns ON when an instruction is finished normally.
M8328
Instruction non-execution
Turns ON when RBFM (FNC278) or WBFM (FNC279)
instruction in another step is executed for a same unit number.
M8329
Instruction execution abnormally complete
Turns ON when an instruction is finished abnormally.
Instruction
Description
FROM(FNC 78)
Read from a special function block
TO(FNC 79)
Write to a special function block
RBFM(FNC278)
Divided BFM read
S
Command
input
M
{{
M8029
FNC278
WBFM
m1
m2
S
n1
n2
M8328
M
Instruction execution
complete
Instruction
non-execution
Unit No. "m1"
PLC
*1 "n2" points are written in each
operation cycle. Writing is executed
in "n1/n2" times. ("n1/n2" is rounded
up if it is not an integer.)
Write
*1
BFM#(m2)
BFM#(m2+n1-1)
+n1-1
S
S
M8329
M
UU
Instruction execution
abnormally complete
