Справочник Пользователя для Mitsubishi Electronics FX2NC
FX Series Programmable Controlers
Applied Instructions 5
5-90
5.8.9
FROM (FNC 78)
Operation:
The FROM instruction reads n words of data
starting from the buffer memory address m
starting from the buffer memory address m
2
of the
special function block with the logical block
position specified as m
1,
The read data is stored in the PLC at head address D for n word
devices.
Points to note:
a) All special function blocks which are addressable with the FROM/TO instructions are
connected to the extension bus on the right hand side of the PLC. Each special function
block can be inserted at any point within the chain of extended units (as long as the system
configuration rules are not broken). Each special function block is consecutively addressed
from 0 to 7 beginning with the one closest to the base unit.
block can be inserted at any point within the chain of extended units (as long as the system
configuration rules are not broken). Each special function block is consecutively addressed
from 0 to 7 beginning with the one closest to the base unit.
b) Each special function unit has different buffer memory registers. These often have a
dedicated use for each individual unit. Before any reading or writing of data is undertaken
ensure that the correct buffer memory allocations for the unit used are known.
m
ensure that the correct buffer memory allocations for the unit used are known.
m
2
: This defines the head address of the (special function blocks) buffer memories being
accessed. m
2
may have a value from the range 0 to 31.
n: This identifies the number of words which are to be transferred between the special
function block and the PLC base unit. n may have a value of 1 to 31 for 16 bit operation but
a range of 1 to 16 is available for 32 bit operation.
function block and the PLC base unit. n may have a value of 1 to 31 for 16 bit operation but
a range of 1 to 16 is available for 32 bit operation.
c) The destination head address for the data read FROM the special function block is
specified under the D operand; and will occupy n further devices.
d) This instruction will only operate when the drive input is energized.
Mnemonic
Function
Operands
Program steps
m
1
m
2
D
n
FROM
FNC 78
(FROM)
FNC 78
(FROM)
Read data from
the buffer
memories of
attached special
function blocks
the buffer
memories of
attached special
function blocks
K, H
Note:
m
m
1
= 0 to 7
K, H
Note:
m
m
2
= FX
(2C)
0 to 31,
FX
FX
2N
0 to
32767
KnY, KnM,
KnS, T, C,
D, V, Z
KnS, T, C,
D, V, Z
K, H
Note:
16 bit op:
n= 1 to 32
32 bit op:
n= 1 to 16
16 bit op:
n= 1 to 32
32 bit op:
n= 1 to 16
FROM,
FROMP:
9 steps
DFROM,
DFROMP:
17 steps
FROMP:
9 steps
DFROM,
DFROMP:
17 steps
FX
0(S)
FX
0N
FX FX
(2C)
FX
2N(C)
FX
(2C)
FX
FX
2N(C)
FX
0N
FX
0(s)
PULSE-P
FX
(2C)
FX
FX
2N(C)
FX
0N
FX
0(s)
16 BIT OPERATION
FX
FX
0N
FX
0(s)
FX
(2C)
FX
2N(C)
32 BIT OPERATION
FROM K2
D10
K10
K6
[ m1 ][ m2 ] [ D ] [ n ]
X1
POWER
FX-8EYT
POWER
FX-4AD
POWER
FX-1HC
POWER
FX-2DA
24V
A-D
OFFSET
GAIN
READY
CH1
CH2
CH3
CH4
24V
D-A
OFFSET
GAIN
GAIN
UP
DOWN
DOWN
CH1
READY
CH2
READY
CH2
Special function
block 0
block 0
Output block
Y50-57
Y50-57
Special function
block 1
block 1
Special function
block 2
block 2
FX-80MR