Alpha 6000 - MODBUS Communication (Group Pb)

Chapter 5 Parameter Introductions
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If motor parameters are known, please set PA.04 ~PA.07 to the values calculated
according to the above formulas.
After motor power (PA.01) change, the inverter will change PA.02~PA.08 according to
the motor power.
PA.08 Rated Speed
Range: 0~24000 rpm【This value depends on the inverter
model】
Note:
 Motor rated speed is used to calculate the value of slip compensation. About the
slip compensation function, please refer to P9.00, P9.01 for details.
5.12 MODBUS Communication (Group Pb)
ALPHA6000/6100 can perform MODBUS communication with a programmable
controller (PLC). The MODBUS network is composed of a master PLC and 1 to 31
(maximum) slave inverters. The master always sends message to slave and the slave
responds to master.
The master can send a message to an addressed slave unit at a time. Therefore, address
numbers are assigned to each slave unit in advance and the master unit specifies a
number to perform signal transmission. The slave unit, which receives the command
from the master unit, executes the function and returns the response to the master unit.
 Communication Specifications
Interface: RS-485
Synchronization: Half-duplex asynchronous.
 Transmission parameters:
Baud rate: Selectable from 1200, 2400, 4800, 9600, 19200, 38400 BPS (parameter
Pb.00)
Data length: fixed at 8 bits
Parity: even parity/no parity/odd parity selectable (parameter Pb.02)
Stop bit: fixed at 1 bit
Protocol: In accordance with MODBUS
Maximum number of units to be connected: 31 units (when RS-485 is used.)
 Data to be sent or received by Communication
Data to be sent or received by communication include run commands, frequency
reference, fault contents, inverter status and parameter writing/reading. No need to