A.4 Modbus Registers
The decimal numbering of register addresses used in this manual is
1-based (the register addresses start from 1). Note that the register addresses in
actual Modbus messages (Modbus Protocol Data Unit (PDU)) start from zero.
Subtract 1 from the decimal addresses presented in this manual to get the
address used in the Modbus message (for example, the decimal register address
1 becomes register address 0 in the actual Modbus message).
CAUTION!
Accessing unavailable (temporarily missing) measurement data does not generate an
exception. “Unavailable” value (a quiet NaN for floating point data or 0000
hex
for integer
data) is returned instead. An exception is generated only for any access outside the applicable
register ranges.
A.4.1 Measurement Data Registers
Table 37 Modbus Measurement Data Registers (Read-Only)
Address
(Decimal)
Address
(Hexadecimal)
Register Description
Data Format
Metric Unit
Floating Point Values
1
0000
hex
Relative humidity
32-bit float
%RH
3
0002
hex
Temperature
32-bit float
°C
7
0006
hex
Dew point temperature
32-bit float
°C
9
0008
hex
Dew/frost point
temperature
32-bit float
°C
11
000A
hex
Dew/frost point
temperature at 1 atm
32-bit float
°C
13
000C
hex
Dew point temperature
at 1 atm
32-bit float
°C
14
000E
hex
Absolute humidity
32-bit float
g/m
3
16
0010
hex
Mixing ratio
32-bit float
g/kg
19
0012
hex
Wet-bulb temperature
32-bit float
°C
21
0014
hex
Water vapor
concentration
32-bit float
ppm
v
23
0016
hex
Water vapor pressure
32-bit float
hPa
25
0018
hex
Water vapor saturation
pressure
32-bit float
hPa
HMP4, HMP5, HMP7, HMP8, TMP1 User Guide
M212022EN-A
48
Summary of Contents for HUMICAP HMP4
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