CET Electric Technology
73
Chapter 5
Modbus Map
This chapter provides a complete description of the Modbus register map (
Protocol Version 3.0
) for the iMeter
6 to facilitate the development of 3
rd
party communications driver for accessing information on the iMeter 6. For
a complete Modbus Protocol Specification, please visit http://
. The iMeter 6 supports the
following Modbus functions:
1)
Read Holding Registers (Function Code 0x03)
2)
Force Single Coil (Function Code 0x05)
3)
Preset Multiple Registers (Function Code 0x10)
4)
Read General Reference (Function Code 0x14)
The following table provides a description of the different data formats used for the Modbus registers. The iMeter
6 uses the
Big Endian
byte ordering system.
Format
Description
UINT16/INT16
Unsigned/Signed 16-bit Integer
UINT32/INT32
Unsigned/Signed 32-bit Integer
Float
IEEE 754 32-bit
Single Precision Floating Point Number
5.1
Basic Measurements
Register
Property
Description
Format
Scale
Unit
0000
RO
Uan
1
Float
x1
V
0002
RO
Ubn
1
Float
0004
RO
Ucn
1
Float
0006
RO
Uln average
1
Float
0008
RO
Uab
Float
0010
RO
Ubc
Float
0012
RO
Uca
Float
0014
RO
Ull average
Float
0016
RO
Ia
Float
x1
A
0018
RO
Ib
Float
0020
RO
Ic
Float
0022
RO
I average
Float
0024
RO
kWa
1
Float
x1
W
0026
RO
kWb
1
Float
0028
RO
kWc
1
Float
0030
RO
kW Total
Float
0032
RO
kvara
1
Float
x1
var
0034
RO
kvarb
1
Float
0036
RO
kvarc
1
Float
0038
RO
kvar Total
Float
0040
RO
kVAa
1
Float
x1
VA
0042
RO
kVAb
1
Float
0044
RO
kVAc
1
Float
0046
RO
kVA Total
Float
0048
RO
PFa
1
Float
x1
-
0050
RO
PFb
1
Float
0052
RO
PFc
1
Float
0054
RO
PF Total
Float
0056
RO
Frequency
Float
x1
Hz
0058
RO
I4 Measured
Float
x1
A
0060
RO
In Calculated
Float
x1
A
0062~0069
Reserved
0070
RO
U2 (Negative Sequence Voltage) Unbalance
UINT16
×10
%
0071
RO
I2 (Negative Sequence Current) Unbalance
UINT16
0072
RO
Uan Over Deviation
INT16
x100
%
0073
RO
Ubn Over Deviation
INT16
0074
RO
Ucn Over Deviation
INT16
0075
RO
Frequency Deviation
INT16
x100
Hz
0076
RO
Uan (Wye)/Uab (3P3W) Angle
UINT16
x100
°
0077
RO
Ubn (Wye)/Ubc (3P3W) Angle
UINT16
0078
RO
Ucn (Wye)/Uca (3P3W) Angle
UINT16
0079
RO
Ia Angle
UINT16
x100
°
0080
RO
Ib Angle
UINT16
0081
RO
Ic Angle
UINT16