12 Program Example
12.1 Reading/Writing Buffer Memory
254
FX
3U
-20SSC-H Positioning Block User's Manual
c) Writing bit information of auxiliary relays to the buffer memory
In the program below, the ON/OFF status of auxiliary relays (M20 to M35) is written to the buffer
memory (BFM #518) in unit No. 1.
d) Writing bit information stored in data registers to the buffer memory
In the program below, the ON/OFF status of each bit of a data register (D201) is written to the buffer
memory (BFM #518) in unit No. 1. Each bit of the data register (D201) should be set to ON or OFF in
advance by bit specification of word devices.
2) FROM/TO instructions (conventional method)
Read and write the contents of the buffer memory using the FROM/TO instructions.
a) Reading and transferring bit information to auxiliary relays
In the program below, the contents of the buffer memory (BFM #28) in unit No. 1 are read and
transferred to auxiliary relays (M40 to M55).
FNC 12
MOV
K4M20
U1\G518
Transfer source
Buffer memory
No.
Unit No.
M20
M21
M35
Write command
Write command
FNC 12
MOV
D201
U1\G518
Transfer source
Buffer memory
No.
Unit No.
D201.0
D201.1
D201.F
M40
M41
M55
Read
command
FNC 78
FROM
K1
K28
K4M40
K1
Transfer
destination
Number of transfer
points
Unit No.
Buffer memory No.
