Mitsubishi Electric MELSEC-A Series Manual page 107

2
REPLACEMENT OF MELSECNET (II) AND /B (PLC TO PLC NETWORK)
2.6.2 Transient instructions
(1) MELSECNET II dedicated instruction
Dedicated instructions that were used on MELSECNET II need to be replaced with the following
dedicated instructions on MELSECNET/H.
The table below shows a comparison between dedicated instructions on MELSECNET II and dedicated
instructions on MELSECNET/H. The table also shows reference items in the Q Corresponding
MELSECNET/H Network System Reference Manual (PLC to PLC Network). Check these reference
items before changing the sequence program.
MELSECNET II
Instruction
Category
name
Reading from
LRDP
local station
Writing to local
LWTP
station
The following describes operation by the instructions.
Instruction Name
Other
READ
station word
SREAD
device read
Other
WRITE
station word
SWRITE
device write
Instruction
Description
name
READ
The master station
SREAD
reads the word
devices (T, C, D, W)
ZNRD
on local stations.
WRITE
The master station SWRITE
writes to the word
devices (T, C, D, W)
on local stations. ZNWR
Execution
station
QCPU
Reads CPU device data on target stations of target network No.
(in 16-bit units)
CPU Network module
READ
Word device
2594
Writes data to CPU device on target station of target network
No. (in 16-bit units)
(Devices on the target station can be turned ON by SWRITE.)
CPU Network module
WRITE
MELSECNET/H
Category
Other station Reads device data on other
word device read stations of target network No.
Reads device data on other
Other station
stations of target network No.
word device read
by A-compatible instructions.
Other station Writes data to devices on
word device other stations of target
write network No.
Writes data to devices on
Other station
other stations of target
word device
network No. by A-compatible
write
instructions.
Description
Network module
Channel 1
Word device
Channel 2
Channel 3
Channel 4
Channel 5
Channel 6
Channel 7
Channel 8
Network module
Channel 1
Word device
Channel 2
Channel 3
Channel 4
Channel 5
Channel 6
Channel 7
Channel 8
Reference
item in the
Description
manual
Section
7.4.5
Section
7.4.5
Section
7.4.5
Section
7.4.5
: Can be used, ×: Cannot be used
Target
station
QnA/ AnU/
QCPU QnA- AnUS(H)
SCPU CPU
CPU
2594
CPU
361
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