Operating instructions

VLT
®
2800, VLT
®
6000 HVAC and VLT
®
8000 AQUA Modbus RTU
■ EXAMPLE 4: Write Parameter 104
Motor Frequency, with 60 Hz
(DataType6: UINT16)
(Conversion factor = 0)
Modbus Function 06
HEX
Preset Single Register
Message sent to Modbus RTU from Modbus master
Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6+7
Slave
Address
Function Register Addr
HI
Register Addr
LO
Preset Data HI Preset Data LO Error Check
01 06 04 0F 00 3C --
Modbus message string:
[01] [06] [04] [0F] [00] [3C] [error check]
[04]+[0F]: Parameter 104 = 040F
HEX
Note that the starting address of a register is the parameter number x 10 - 1
in HEX.
104 x 10 = 1040 - 1 = 1039 = 040F
HEX
[01] [06] [04] [0F] [00] [3C] [error check]
[00+[3C]: Speed (60 Hz) = 3C
HEX
Message returned to Modbus master from Modbus RTU
Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 + 7
Slave
Address
Function Register Addr
HI
Register Addr
LO
Preset Data HI Preset Data LO Error Check
01 06 04 0F 00 3C --
All values are in hexadecimal.
■ EXAMPLE 5: Read Parameter 514
Motor Current =3Amps
(DataType7: UINT32)
(Conversion factor = -2)
Modbus Function 03
HEX
Read Holding Registers
Message sent to Modbus RTU from Modbus master
Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6+7
Slave
Address
Function Start Addr HI Start Addr LO No. of Points HI No. of Points
LO
Error Check
01 03 14 13 00 02 --
Parameter 514 (5139) = 1413
HEX
Note that the starting address of a register is the parameter number x 10 - 1 in HEX.
MG.10.S2.02 - VLT is a registered Danfoss trademark
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