Omron 3G3RX - Message Configuration: Query

4-165
4-4 Communication Function
4
Functions
Below is each frame format (command).
Message Configuration: Query
<Slave Address>
•Pre-set numbers ranging from 1 to 247 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 RX corresponds with the following data formats used in the ModBus.
<Function Code>
•Specifies the function for the Inverter to perform.
•Below are the function codes supported by the RX.
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
16
+ X
15
+ X
2
+ 1).
Header (Silent interval)
Slave address
Function code
Data
Error check
Trailer (Silent interval)
Data name Description
Coil 2-value data (1-bit long) that can be referred to or changed
Holding register 16-bit long data that can be referred to or changed
Function code Function
Maximum number of
data bytes in 1 message
Maximum data number in
1 message
01h Reading coil status 4 32 coils (in bits)
03h
Reading holding register
content
8 4 registers (in bytes)
05h Writing into the coil 2 1 coil (in bits)
06h
Writing into the holding
register
2 1 register (in bytes)
08h Loop-back test 
0Fh Writing into multiple coils 4 32 coils (in bits)
10h Writing into multiple registers 8 4 registers (in bytes)