Precautions For Accessing Other Stations - Mitsubishi Electric Melsec Q Series User Manual

4 WHEN THE Q/LCPU ACCESSES THE PROGRAMMABLE CONTROLLER
OF ANOTHER STATION USING THE DATA LINK INSTRUCTION

4.2 Precautions for Accessing Other Stations

The following describes precautions when accessing other stations via the Ethernet
module using the data link instructions.
(1) Executing multiple instructions at one time (common to the data link
Channel 1: Write to station No.1
Channel 2: Read from station No.1
Channel 3: Write to station No.2
Channel 4: Read from station No.2
Channel 1: sending
Channel 3: receiving
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instructions)
(a) When simultaneously accessing multiple other stations from the own station,
change the channel setting of the own station for each request target.
Station No.3
(Own station)
Channel 1
Channel 2
Channel 3
Channel 4
(b) When accessing other stations using the same channel number, access the
next station after the last access to other station is completed.
The completion status can be checked by the completion device of the data
link instruction.
(c) When making access mutually between the own station and another station,
change the channel of the own station for each dedicated link instruction.
Station No.1
(Own station)
SEND
Channel 1
RECV
Channel 3
A maximum of eight instructions can be executed at one time as long as
the channel numbers (1 to 8) designated in the control data of each
instruction do not overlap.
(d) Channels used for RECV instructions cannot be used for any other
instructions. Channels used for other instructions must be changed.
Station No.1
(Other station)
WRITE
READ
Station No.2
WRITE
(Other station)
READ
Station No.2
(Other station)
RECV Channel 1: receiving
Channel 1
SEND
Channel 3 Channel 3: sending
MELSEC-Q/L
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