Hitachi S10VE, User Manual

Page: 118 / 506

7. Wiring
7-15
7.7.2 Examples of improper remote I/O wiring
Wiring the remote I/O cables in any of the incorrect ways shown in Table 7-4 can distort the waveform of the
signal on the lines, causing communication errors. Take care to wire the cables correctly.
Table 7-4 Correct and incorrect remote I/O wiring
C
or
rec
t w
ir
ing
E
x
amp
les
o
f i
nc
or
rec
t w
ir
in
g
Notice
● To avoid malfunction, set a terminating resistance (150Ω) at any RI/O-IF module ports to which a
remote I/O cable will not be connected. This prevents external noise from entering the system.
RI/O-1
1 2
RI/O
CPU unit
1 2
RI/O
PI/O unit
1 2
RI/O
PI/O unit
■ Do not mix cable types in a given line.
RI/O-1
TB
TB
1 2 RI/O
CPU unit
1 2 RI/O
PI/O unit
1 2 RI/O
PI/O unit
■ Connect cables directly, not via a terminal block.
RI/O-1
RI/O-2
1 2
RI/O
CPU unit
1 2
RI/O
PI/O unit
1 2
RI/O
PI/O unit
1 2
RI/O
PI/O unit
■ Do not form a closed loop.
■ Do not use a branching connection.
RI/O-1
1 2 RI/O
CPU unit
1 2 RI/O
PI/O unit
1 2 RI/O
PI/O unit
1 2 RI/O
PI/O unit
■ A maximum of 12 units can be connected per line, and you must terminate the line at both ends.
■ The unused port of the RI/O-IF module in the CPU unit must be terminated with 150Ω resistance.
Termination
Termination (150Ω)
Unused
RI/O-1
Termination
1 2 RI/O
CPU unit
1 2 RI/O
PI/O unit
1 2 RI/O
PI/O unit
1 2 RI/O
PI/O unit
Termin
Termin Termination
Termin
RI/O-1 RI/O-2
■ There are no restrictions in terms of the positioning of the CPU unit.
1 2 RI/O
PI/O unit
1 2 RI/O
CPU unit
1 2 RI/O
PI/O unit
1 2 RI/O
PI/O unit