Mitsubishi Electric Melsec Q Series User Manual page 95

4 WHEN THE Q/LCPU ACCESSES THE PROGRAMMABLE CONTROLLER
OF ANOTHER STATION USING THE DATA LINK INSTRUCTION
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(5) Channels used by the ZNRD and ZNWR instructions
The ZNRD and ZNWR instructions for Ethernet modules are executed using the
following channels of the target Ethernet module.
• ZNRD: Channel 1
• ZNWR: Channel 2
Do not use the channels used by the ZNRD and ZNWR instructions listed above
for other data link instructions in an Ethernet module mounted station that
executes the ZNRD and ZNWR instructions. Also, do not execute data link
instructions from other stations on the channels listed above in an Ethernet
module mounted station that executes the ZNRD and ZNWR instructions.
POINT
(1) See Chapter 3 for details of the following when performing other station access
using the data link instructions.
• The accessible range and accessible stations of the other stations
• Setting to perform other station access
• Other station access procedure
(2) The communication using the data link instructions on the Ethernet is
performed with UDP/IP.
When executing each data link instruction except for ZNRD and ZNWR, it is
recommended to designate a value greater than "1" to the number of retries
setting area of the control data storage device.
(3) See the reference manual for each network regarding the link data
send/receive processing and processing time in data communication with the
programmable controller CPU of another station via other networks.
(4) For details about data designation methods in the data link instruction, see
Chapter 6.
MELSEC-Q/L
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