Technical Bulletin

Modbus TCP On-Board Communications
24 PowerXL DG1 Series VFD MN040010EN—May 2014 www.eaton.com
Modbus Communication Standards
Example of the request to read coils 2000–2003 from Slave
device 18.
Table 37. Request to Read Coils
Example of the request to read Discrete Inputs 2000–2003
from Slave device 18.
Table 38. Request to Read Discrete Inputs
Example of the request to read Holding Registers 2000–2003
from Slave device 18.
Table 39. Request to Read Holding Registers
Example of the request to read Input Registers 2000–2003
from Slave device 18.
Table 40. Request to Read Input Registers
Example of the request to read exception status from Slave
device 18.
Table 41. Request to Read Exception Status
Example of Read Diagnostics from Slave address 18.
Table 42. Read Diagnostics
Item Code Description
Slave address 0x12
Function code 0x01
Start address High 0x07 Starting address 0x07D0 hex (= 2000)
Start address Low 0xD0
Number of coils High 0x00 Number of coils 0x0003 hex (= 3)
Number of coils Low 0x03
CRC High 0x7E
CRC Low 0x25
Item Code Description
Slave address 0x12
Function code 0x02
Start address High 0x07 Starting address 0x07D0 hex (= 2000)
Start address Low 0xD0
Number of Discrete
Inputs High
0x00 Number of Discrete Inputs
0x0003 hex (= 3)
Number of Discrete
Inputs Low
0x03
CRC High 0x3A
CRC Low 0x25
Item Code Description
Slave address 0x12
Function code 0x03
Start address High 0x07 Starting address 0x07D0 hex (= 2000)
Start address Low 0xD0
Number of Holding
Registers High
0x00 Number of Holding Registers
0x0003 hex (= 3)
Number of Holding
Registers Low
0x03
CRC High 0x07
CRC Low 0xE5
Item Code Description
Slave address 0x12
Function code 0x04
Start address High 0x07 Starting address 0x07D0 hex (= 2000)
Start address Low 0xD0
Number of Input
Registers High
0x00 Number of Input Registers
0x0003 hex (= 3)
Number of Input
Registers Low
0x03
CRC High 0xB2
CRC Low 0x25
Item Code Description
Slave address 0x12
Function code 0x07
CRC High 4C
CRC Low D2
Item Code Description
Slave address 0x12
Function code 0x08
Sub function High 0x00 Sub function code 0x0000 (= 0)
Note. Only support sub function code
0x0000
Sub function Low 0x00
Data High 0xA5 Data 0xA5A5 (= 42405)
Data Low 0xA5
CRC High 0x59
CRC Low 0x83