Coaxial Bus System - Mitsubishi Electric Q Series Reference Manual

4 SETUP AND PROCEDURES BEFORE STARTING THE OPERATION

4.6.2 Coaxial bus system

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(1) Precautions in connecting
(a) Restrictions on the cable length between the stations
1) When connecting between the network modules, the cable lengths
indicated in the table below should be used according to the number of
stations connected.
A communication error may occur if a cable length other than the
lengths indicated in the table is used.
Number of stations connected
Station-to-station cable length
Cable type
0 to 1 m (3.28 ft.)
1 (3.28 ft.) to 5 m (16.41 ft.)
5 (16.41 ft.) to 13 m (42.65 ft.)
13 (42.65 ft.) to 17 m (55.78 ft.)
17 (55.78 ft.) to 25 m (82.03 ft.)
25 (82.03 ft.) to 300 m (984.3 ft.)
300 (984.3 ft.) to 500 m (1640.5 ft.)
2) If there is a possibility of adding more stations to expand the existing
system, the cables should be installed by considering restriction 1)
mentioned above in advance.
3) When using a repeater module (models A6BR10 or A6BR10-DC), use
the station-to-station cable length for "10 to 33" stations, regardless of
the number of stations connected or the number of repeater modules.
(b) Cable installation precautions
1) Install the coaxial cables at least 100 mm (3.94 in.) away from other
power cables and control cables.
2) Consider to use double shield coaxial cables in locations where there is
excessive noise.
Double shield coaxial cable
Mitsubishi Cable · · · 5C-2V-CCY
5C-2V connector plug can be applied to double-shielded coaxial cable.
Connect the plug to the coaxial cable inside the double shield coaxial
cable.
Ground the shielded section, external part of the double shield coaxial
cable, as shown above.
Locate external conductor (grounding) of the double shielded cable
approximately 10mm away from the connector plug for 5C-2V. (Do not
contact them.)
2 to 9 stations
3C – 2V
(cable less than 1m (3.28 ft.) in length cannot be used.)
Ground
External conductor (ground)
Sheath Sheath
Approximately 10mm
MELSEC-Q
10 to 33 stations
5C – 2V 3C – 2V
: Allowed : Not allowed
Cable close-up
Internal Insulator
conductor
External Sheath
External
conductor
conductor
(ground)
5C – 2V
Sheath
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