Vaisala HMP4 - Modbus; Default Communication Settings; Measurement Data Registers

Modbus
Default Communication Settings
Table 1 Default Modbus Serial Communication Settings
Property Description/Value
Serial bit rate 19200
Parity None
Number of data bits 8
Number of stop bits 2
Flow control None
Modbus device address 240
You can use up to ten probes on the same RS-485 line. You must configure each probe on the
line to have a dierent Modbus address.
Measurement Data Registers
Measurement data is also available as integer registers if use of floating point is a problem for
your implementation. See HMP Series User Guide (M212022EN) available at www.vaisala.com.
Table 2 Floating Point Measurement Data Registers (Read-Only)
Register
Number
(Decimal)
Address
(Hexadecimal)
Register Description Data Format Metric Unit
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
15 000E
hex
Absolute humidity 32-bit float
g/m
3
17 0010
hex
Mixing ratio 32-bit float g/kg
19 0012
hex
Wet-bulb temperature 32-bit float °C
21 0014
hex
Water concentration 32-bit float ppm
v
20 M211982EN-D