Wiring For Remote I/O; Connecting The Remote I/O Cables; Figure 7-15 Wiring Of Remote I/O Cables - Hitachi S10VE User Manual

7. Wiring

7.7 Wiring for remote I/O

This section explains how to connect the remote I/O cables.

7.7.1 Connecting the remote I/O cables

● An RI/O-IF module is equipped with two remote I/O cable connection ports (RI/O-1 and RI/O-2). You can
connect a maximum of 12 PI/O units to each port.
● The remote I/O cable connection ports (RI/O-1 and RI/O-2) of a PI/O unit are connected internally. Note that
the port numbers of the CPU module have no relation to these port numbers. When connecting to the RI/O-1
port of the RI/O-IF module, use a station number in the range from 00 to 3F. When connecting to the RI/O-2
port, use a station number in the range from 40 to 7F.
● You must terminate the ends of the remote I/O line at the RI/O-IF module and remote I/O station module. As
the terminating resistor, you can use the built-in 150Ω resistor, or an externally connected resistor with an
arbitrary resistance value. Select the terminating resistance based on the characteristic impedance of the
remote I/O cable. For details, see 7.7.4 Setting terminating resistance.
● Improper wiring can prevent communication. Take care to wire the remote I/O cables in the prescribed way.
For details, see 7.7.2 Examples of improper remote I/O wiring.
● The shield of the remote I/O cable must be grounded at one end only on the RI/O-IF side. Although the shield
can be grounded at both ends if the grounding points are the same, we recommend that you keep your wiring
approach consistent by grounding the shield at one end only on the RI/O-IF module side.
CPU unit
RI/O
1
Requires
termination
PI/O unit 1
RI/O
1
CPU unit
RI/O
1
Unuse
Requires
termination
■ Be sure to set a 150Ω terminal resistor on any unused port of an RI/O-IF module in the CPU unit.
● 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.
PI/O unit 1
Requires
termination
RI/O
2 1
RI/O-2
PI/O unit 2
RI/O
2
1
RI/O-1
PI/O unit 1
Requires
termination
RI/O
(150Ω)
2 1
RI/O-1

Figure 7-15 Wiring of remote I/O cables

PI/O unit 2
RI/O
2 1
PI/O unit 3
RI/O
1
2
PI/O unit 2
RI/O
2 1
Notice
7-14
PI/O unit N
RI/O
2 1
Requires
termination
PI/O unit N
RI/O
2 1
Requires
termination
PI/O unit N
RI/O
2 1
Requires
termination
N≤12
2
N≤12
2
N≤12
2