15.10 Fnc 79 - To / Write To A Special Function Block - Mitsubishi Electric FX3G SERIES Programming Manual

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
15.10 FNC 79 – TO / Write To A Special Function Block
Outline
This instruction writes data from a PLC to buffer memories (BFM) in a special extension unit/block.
When a large capacity of data is written to buffer memories (BFM) by this instruction, a watchdog timer error may
occur. When splitting the data to be written does not affect the control, use WBFM (FNC279) instruction.
1. Instruction format
FNC 79
D TO
2. Set data
Operand Type
m1
m2
S
n
3. Applicable devices
Bit Devices
Oper-
and System User
Type
X Y M T C S D .b KnX KnY KnM KnS
m1
m2
S
n
Explanation of function and operation
1. 16-bit operation (TO and TOP)
→ For the common items between FROM instruction and TO instruction, refer to Subsection 15.9.1.
PLC (word device) → Special extension unit/block (BFM)
"n"-point 16-bit data starting from
from the buffer memory (BFM) # m2 inside a special extension unit/block No. m1.
Command
input
FNC 79
454
Mnemonic
16-bit Instruction
P
TO
9 steps
TOP
Unit number of a special extension unit/block
(K0 to K7 from the right side of the main unit)
Transfer destination buffer memory (BFM) number
Device number storing the transfer source data
Number of transfer points
Digit Specification
S inside a PLC are transferred (written) to "n"-point buffer memories starting
m1 m2
TO
15 External FX I/O Device – FNC 70 to FNC 79
15.10 FNC 79 – TO / Write To A Special Function Block
→ For WBFM (FNC279) instruction, refer to Section 31.2.
Operation Condition
32-bit Instruction
Continuous
Operation
Pulse (Single)
Operation
Description
Word Devices
Special
System User
Unit
T C D R U \G
S n
Number of transfer points
n = 1 to 32767
Transfer source (PLC)
Transfer destination (Special
extension unit/block) BFM #
m2 = 0 to 32766
Unit No.
m1 = 0 to 7
Mnemonic Operation Condition
DTO
17 steps
DTOP
16- or 32-bit binary
16- or 32-bit binary
16- or 32-bit binary
16- or 32-bit binary
Others
Con- Real
Index
stant Number
V Z Modify K H E
Continuous
Operation
Pulse (Single)
Operation
Data Type
Charac-
Pointer
ter String
" " P