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

7 APPLICATION FUNCTIONS

7.6 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 "Supplementary
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.
1M 1
P
IN
OUT
OUT IN
1N 6
S
(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/25 Mbps.
REMARKS
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.
If the multiplex transmission function is used in the configuration where the number
of connected stations or the assigned link devices is less than the above, the link
scan time may be increased compared to the case where the function is not used.
1N 2
S
IN
OUT
OUT IN
1N 5
S
MELSEC-Q
1N 3
S
IN OUT
Forward loop
OUT IN
Reverse loop
1N 4
S
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