Hitachi L700 SERIES Instruction Manual page 161

Connection
As illustrated below, connect the inverters in parallel to the external control system, and connect the
RP and SN terminals with a jumper on the inverter at the end of the network. (Similarly jumper the RP
and SN terminals when only one inverter is connected to the external control system for RS485
communication.) Connecting the RP and SN terminals enables the terminating resistor in the control
circuit terminal block board of the inverter, which suppresses signal reflections.
External control
system
(2) Required settings
The following table lists the inverter settings required for the RS485 communication:
Item
Communication speed
selection
Node allocation
Communication data length
selection
Communication parity
selection
Communication stop bit
selection
Selection of operation after
communication error
Communication trip limit time
setting
Communication wait time
Communication mode
selection
SP SN RP SN
Function code Data or range of data
C071
C072
C073
C074
C075
C076
C077 0.00 to 99.99 (s)
C078 0. to 1000. (ms)
C079
4 - 99
Chapter 4 Explanation of Functions
SP SN RP SN
02 Loopback test
03 2,400 bps
04 4,800 bps
05 9,600 bps
06 19,200 bps
Assignment of a station number to the
inverter
1. to 32. (Set this item when your inverter is
connected together with other(s) to a
control system.)
7 7 bits
8 8 bits
00 No parity
01 Even parity
02 Odd parity
1 1 bit
2 2 bits
00 Tripping
Tripping after decelerating and stopping
01
the motor
02 Ignoring the errors
03 Stopping the motor after free-running
04 Decelerating and stopping the motor
Limit length of time to determine
communication train disconnection
Time to wait until the inverter returns a
response
00 ASCII mode
01 Modbus-RTU mode
SP SN RP SN
Description