Omron RX2 Series - Page 598

9 Communications Functions
9 - 6
High-function General-purpose Inverter RX2 Series User’s Manual
The format of a query frame (command) is as follows.
<Slave Address>
• A serial number from 1 to 32 preset for each inverter (slave). Only the inverter that matches the slave
address specified in the query will capture that query.
• Set the slave address to 0 to perform broadcasting (distributing a query to all slave addresses at a
time).
• During a broadcast, you cannot perform data call or loop-back operation.
<Function Code>
This specifies the function to be performed by the inverter.
Function Code
<Data>
• This sends the function command.
• The data format differs depending on the function code.
<Error Check>
• CRC (Cyclic Redundancy Check) is used for error checking.
• The CRC code is 16-bit data generated for any data block with a data length in 8-bit unit.
• For CRC code generation, the following generator polynomial is used: CRC-16 (X
16
+ X
15
+ X
2
+ 1).
Query Frame Configuration
Slave address
Function code
Data
Error check
Function code Function
Maximum number of
data bytes per message
Maximum number of
coils/registers per message
01 hex Reads out the state of coil 4 32 coils (bitwise)
03 hex
Reads out the content of retention
register
32 16 registers (in bytes)
05 hex Writes to coil 2 1 coil (bitwise)
06 hex Writes to retention register 2 1 register (in bytes)
08 hex Loopback test – –
0F hex Writes to multiple coils 4 32 coils (bitwise)
10 hex Writes to multiple retention registers 32 16 registers (in bytes)
Data name Description
Coil Two values can be read and written (1 bit length).
Holding register Data with 16 bit length can be read and written.