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Example
Read PNU 342 which is mapped to register 0x0D5B(RegAdr = 342 x 10 - 1)
Field Name
Example (HEX)
Slave address
01
Function
03
Starting Address HI
0D
Starting Address LO
5B
No. of Points HI
00
No. of Points LO
02
Error Check (CRC)
-
Table 5.1: Request frame
Response
The register data in the response message are packed as two bytes per register, with the binary contents right justified within each byte. For each register,
the first byte contains the high order bits and the second contains the low order bits.
Field Name
Example (HEX)
Slave address
01
Function
03
Byte count
04
Data HI (Register 3419)
00
Data LO (Register 3419)
00
Data HI (Register 3420)
00
Data LO (Register 3420)
03
Error Check (CRC)
-
Table 5.1: Normal response frame
5.5.5 Preset Single Register (06
HEX
)
Description
This function presets a value into a single holding register.
Query
The query message specifies the register reference to be preset. Register addresses start at zero, i.e. register 1 is addressed as 0.
Example
Write 1 to PNU3 which is mapped to register 0x001D (3 x 10-1 = 29 = 001DHex)
Field Name
Example (HEX)
Slave address
01
Function
06
Starting Address HI
00
Starting Address LO
1D
No. of Points HI
00
No. of Points LO
01
Error Check (CRC)
-
Table 5.1: Request frame
VLT
®
Micro Drive FC 51 Operating Instructions
5 Modbus RTU
MG.02.A4.02 - VLT
®
is a registered Danfoss trademark
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