Hitachi SJ7002 Series Instruction Manual page 286

Serial Connection
Diagrams
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The serial connector is to the left of the control logic connector as shown below:
Serial
Communications
Connector
SP SN RP SN
Each device requires just two connections in parallel for data transmission and reception.
Additionally, the device at each physical end of the wiring requires a termination resistor. The
SJ700 has built-in termination resistors that become part of the circuit when you add a jumper
2
as shown. The termination resistor helps to suppress electrical reflections.
Send/receive (–)
Send/receive (+)
TIP: Each slave device on the serial network must have a unique node address, set by parame-
ter C072. If this is a new application, we recommend connecting one new device at a time and
checking the communications after each addition.
Termination resistor (–)
Termination resistor (+)
Send/receive (–) Negative
Send/receive (+) Positive
SJ700 SJ700
SP SN RP SN SP SN RP SN
B–3
SJ700 Inverter
2
SJ700
SP SN RP SN
Termination jumper