12 Program Example
12.1 Reading/Writing Buffer Memory
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3U
-20SSC-H Positioning Block User's Manual
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Buffer
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b) Reading and transferring bit information to data registers
In the program below, the contents of the buffer memory (BFM #28) in unit No. 1 are read and
transferred to a data register (D200). The read bit information is used in bit specification of word
devices.
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.
D200.0
D200.1
D200.F
Read
command
FNC 78
FROM
K1
K28
D200
K1
Transfer destination
Number of transfer
points
Unit No.
Buffer memory No.
M20
M21
M35
Read
command
FNC 79
TO
K1
K518
K4M20
K1
Transfer source
Number of transfer
points
Unit No.
Buffer memory No.
D201.0
D201.1
D201.F
Read
command
FNC 79
TO
K1
K518
D201
K1
Transfer source
Number of transfer
points
Unit No.
Buffer memory No.
