Omron SYSDRIVE RX Series User Manual page 268

4-4 Communication Function
Below is each frame format (command).
Message Configuration: Query
4
<Slave Address>
•Pre-set numbers ranging from 1 to 32 in each Inverter (slave). (Only the Inverter having the same
slave address as the query takes in the corresponding query.)
•Broadcasting can be performed by setting the slave address to "0".
•Data call or loop-back cannot be performed while broadcasting.
<Data>
•Sends the function command.
•The 3G3RX corresponds with the following data formats used in the ModBus.
Coil
Holding register
<Function Code>
•Specifies the function for the Inverter to perform.
•Below are the function codes supported by the 3G3RX.
Function Code
Function code
<Error Check>
•CRC (Cyclic Redundancy Check) is used for the ModBus-RTU error check.
•The CRC code is a 16-bit data generated for the block of random length data in the 8-bit unit.
•To prepare the CRC code, use a generation polynomial of CRC-16 (X
4-159
Header (Silent interval)
Slave address
Function code
Data
Error check
Trailer (Silent interval)
Data name
2-value data (1-bit long) that can be referred to or changed
16-bit long data that can be referred to or changed
Function
01h Reading coil status
Reading holding register
03h
content
05h Writing into the coil
Writing into the holding
06h
register
08h Loop-back test
0Fh Writing into multiple coils
10h Writing into multiple registers
Description
Maximum number of Maximum data number in
data bytes in 1 message
4 32 coils (in bits)
8 4 registers (in bytes)
2 1 coil (in bits)
2 1 register (in bytes)
⎯
4 32 coils (in bits)
8 4 registers (in bytes)
16
+ X
1 message
15 2
+ X + 1).