Multiplex Transmission Function (Optical Loop System) - Mitsubishi Electric QJ71LP21 Reference Manual

7 APPLICATION FUNCTIONS

7.4 Multiplex Transmission Function (Optical Loop System)

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The multiplex transmission function allows high-speed communications using duplex
transmission paths (both the forward and reverse loops) in the optical loop system.
In order to execute the multiplex transmission function, setting for the "Supplemental
settings" of the common parameters is required. Note that this setting is not allowed
unless the total number of link stations is four stations or more.
(1) Using the multiplex transmission function, the high-speed communication is
performed using both the forward and reverse loops effectively.
1MR
IN OUT
OUT
IN
1R5
(2) If an error occurs in the transmission path while the multiplex transmission function is
used, data linking continues by communicating only using the transmission path on
one side of either the forward or reverse loop, or by switching to the communication
using loopback. The transmission speed in this case is 10 Mbps/25Mbps.
1MR
IN OUT
OUT IN
1R5
REMARK
The multiplex transmission function is effective only in reducing the link scan time
when the number of connected stations is 16 or more and the link devices assigned
with common parameters is 2,048 bytes or more. The link scan time will be 1.1 to
1.3 times faster compared to when the multiplex transmission function is not used.
1R1
IN OUT
OUT
IN
1R4
1R1
IN OUT
OUT IN
1R4
Loopback
MELSEC-Q
Master
1R2
IN OUT
Forward loop
OUT
IN
Reverse loop
1R3
Loopback
1R2
IN OUT
Forward loop
OUT IN
Reverse loop
1R3
Down
Remote
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