Omron SYSDRIVE MX2 SERIES, User Manual

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8 Communications Functions
8 - 8 Multi-function Compact Inverter 3G3MX2-V1 User’s Manual (I585-E1)
A slave address is a serial number from 1 to 247 set in advance for each inverter (slave). (Only the
inverter that matches the slave address specified in the query will capture that query.)
z Simultaneous broadcast to up to five groups
Set the slave address to 0 to perform broadcasting (simultaneous broadcast).
In a broadcast, all slaves receive data, but they return no response to it.
Moreover, during a broadcast, this inverter cannot perform data read or loop-back operation.
Although the Modbus specifications define the slave addresses between 1 to 247, using the slave
addresses 250 to 254 on the master side enables you to perform simultaneous broadcasting by
group. (In this case, the slaves return no response.)
Please note that this function is enabled for write commands (function code: 05 hex, 06 hex, 0F hex,
and 10 hex) only.
A function code specifies the function to be performed by the target inverter(s).
The supported function codes are as shown in the table below.
z Function code
A message sends data related the function code.
The data transmission format differs depending on the function code.
Among the data used in Modbus communication, the 3G3MX2 Series supports the following data types.
Slave Address
Slave address Recipient
250 (FA hex) Simultaneous broadcast to slave addresses 01 to 09
251 (FB hex) Simultaneous broadcast to slave addresses 10 to 19
252 (FC hex) Simultaneous broadcast to slave addresses 20 to 29
253 (FD hex) Simultaneous broadcast to slave addresses 30 to 39
254 (FE hex) Simultaneous broadcast to slave addresses 40 to 247
Function Code
Function code Function
Maximum number of
data bytes per
message
Maximum number of data per
message
01 hex Read Coil Status 4 32 coils (in bits)
03 hex Read from Holding Register 32 16 registers (in bytes)
05 hex Write to Coil 2 1 coil (in bits)
06 hex Write to Holding Register 2 1 register (in bytes)
08 hex Loop-back Test
− −
0F hex Write to Multiple Coils 4 32 coils (in bits)
10 hex Write to Multiple Holding Registers 32 16 registers (in bytes)
17 hex
Read/Write from/to Multiple
Holding Registers
32 each for read/write
operation
16 registers each for read/write
operation (in bytes)
Data
Data name Description
Coil Binary data (1 bit) that supports read/write operation
Holding register 16-bit data that supports read/write operation