Hitachi IR.Station, Hardware Manual

Page: 37 / 54

5 CABLING
- 27 -
An example of wiring when modules in different I/O units are connected
When connecting modules in different I/O units, leave the FG terminal of the IR.Station
module open. If connected, the noise resistance will decrease because of different
grounding potentials.
Ground the FG terminal of one of the terminating units only.
PS
LQV000
POWER
ON
OF F
H
N
LG
FG
AC100-120V
DC5V
GND
SERVICE
CHECK
POWER
HITACHI
D.INPUT
LQX100
100- 120 VA C
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
D.INPUT
LQX100
100- 120 VA C
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
LG
FG
FG
FG
See "Power supply cabling."
LG
See "Power supply cabling."
PS IO
LQS021
ST.NO
IR.Station
U
L
TX/RX
ERR
BIT
RATE
IR.Station IO
Twisted-paircable
(100 m at maximum)
TB
(Collective
connection
of LG lines)
TB
(Collective
connection
of FG lines)
100 VAC
50 Hz/60 Hz
Do not ground the FG terminal
of the IR.Station module.
2
FG/LG cable size
Cable inside the mount base: 2 mm or more
Cable outside the mount base: 5.5 mm or more
2
REQUIREMENT
If grounding is not perfect, you may get an electric shock and be injured. In an
extreme case, you will be put to death. Improper grounding may allow noises to
disturb the system.
Follow instructions below to ground the LG (Line Ground), FG (Frame Ground),
and SHD (Shield) terminals.
Ground the body of the mount base. Do not remove the insulation sheet from
the mount base to insulate the mount base.
Ground the LG and FG terminals separately (with different grounding wires).
The LG terminal is to eliminate power noises. The FG and SHD terminals are
to eliminate line noises. Be sure to ground them separately to prevent their
mutual interference.
Ground one FG terminal of the IR.Station module for each line.
DANGER
Always turn off power to the system before mounting or demounting the modules
and cables. Otherwise, you may get an electric shock when you involuntarily
touch the power terminal or the system may be damaged by a short-circuiting or
noises. Be sure to turn off and make sure power is not alive before starting the
job.