22
MG.10.P2.22 VLT is a registered Danfoss trade mark
Message
Translation
Examples
(continued)
EXAMPLE FIVE: Read Parameter 514,
(Parameter 520 for VLT 5000) Motor
Current = 3 Amps
(Data Type 7 – UINT32)
(Conversion Factor = -2)
Modbus Function 03
HEX
Read Holding Registers
Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6
Slave
Address
Function Start Addr HI Start Addr LO No. of Points
HI
No. of Points
LO
Error Chec
01 03 14 13 00 02 --
Message sent to Modbus master from Modbus RTU option cardMessage sent to Modbus master from Modbus RTU option card
Message sent to Modbus master from Modbus RTU option cardMessage sent to Modbus master from Modbus RTU option card
Message sent to Modbus master from Modbus RTU option card
Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7
Slave
Address
Function Byte Count Data HI
(Reg 45140)
Data LO
(Reg 45140)
Data HI
(Reg 45141)
Data LO
(Reg 45141)
Error Check
01 03 04 00 00 01 2C --
EXAMPLE FOUR: Write Parameter 104,
Motor Frequency, with 60 Hz
(Data Type 6 – UINT16)
(Conversion factor = 0)
Modbus Function 06
HEX
Preset Single Register
Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6
Slave
Address
Function Register
Addr HI
Register
Addr LO
Preset Data
HI
Preset Data
LO
Error Check
01 06 04 0F 00 3C --
Message rMessage r
Message rMessage r
Message r
eturetur
eturetur
etur
ned to Modbus master frned to Modbus master fr
ned to Modbus master frned to Modbus master fr
ned to Modbus master fr
om Modbus Rom Modbus R
om Modbus Rom Modbus R
om Modbus R
TU option carTU option car
TU option carTU option car
TU option car
dd
dd
d
Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6
Slave
Address
Function Register
Addr HI
Register
Addr LO
Preset Data
HI
Preset Data
LO
Error Check
01 06 04 0F 00 3C --
Message sent to Modbus RTU option card from Modbus masterMessage sent to Modbus RTU option card from Modbus master
Message sent to Modbus RTU option card from Modbus masterMessage sent to Modbus RTU option card from Modbus master
Message sent to Modbus RTU option card from Modbus master
Modbus message string:
[01] 06] [04] [0F] [00] [3C] [ error check ]
{
Parameter 104 = 0F04
HEX
(reversed)
Note that the starting address of a register is the parameter number x 10 -1 in HEX.
104 x 10 = 1040 -1 = 1039 = 0F04
HEX
(reversed)
Speed (60 Hz) = 3C
HEX
Modbus message string:
[01] 06] [04] [0F] [00] [3C] [ error check ]
{
Message sent to Modbus RTU option card from Modbus masterMessage sent to Modbus RTU option card from Modbus master
Message sent to Modbus RTU option card from Modbus masterMessage sent to Modbus RTU option card from Modbus master
Message sent to Modbus RTU option card from Modbus master
Parameter 514 (5139) = 1413
HEX
All values are in hexadecimal.