Self-Loopback Test - Mitsubishi Electric Melsec QJ71LP21 Reference Manual

4 SETUP AND PROCEDURES BEFORE STARTING THE OPERATION

4.5.1 Self-loopback test

Optical loop system
Connect IN
and OUT
IN
OUT
1
MODE
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This test checks the hardware of a standalone network module, including the
send/receive circuit and cable of the transmission system.
POINT
Do not connect or disconnect the cable or terminating resistor during execution of
the test. (Doing so will result in test failure.)
(1) System configurations
(a) Optical loop system
Connect IN and OUT terminals of the network module with an optical fiber
cable.
(b) Coaxial bus system
Connect terminating registers to both F-shaped connectors of the network
module.
(c) Twisted bus system
Connect a terminating register between DA and DB of the network module.
Coaxial bus system
(2) Test mode settings
(a) Optical loop system
Set the mode setting switch of the network module to "1" and "5" for
10Mbps and 25Mbps respectively.
(b) Coaxial bus system
Set the mode setting switch of the network module to "1".
(c) Twisted bus system
Set the station number/mode setting switches of " 10" and " 1" to "TEST"
and "7" respectively.
Twisted bus system
Connect
terminating resistors
MELSEC-Q
Connect
terminating resistors
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