Output via the serial bus – Vaisala HMP240 User Manual
Page 79

HMP240
M210300en
Appendix 1: Serial commands
77
3.
OUTPUT VIA THE SERIAL BUS
R
Starting the measurement output
R
Starts output of measurements to the peripheral devices (PC display or
printer); output interval is set with command INTV. The output format
depends on the transmitter configuration and variables used. The sequence,
however, is always the same: relative humidity, temperature, dewpoint
temperature, absolute humidity, mixing ratio, wet bulb temperature and
dewpoint difference. An example:
RH= 43.0 %RH T= 21.0 'C Tdp= 8.0 'C x= 6.7 g/kg Tw=
13.7 'C
When the transmitter sends out the readings, the serial interface does not echo
any commands; the only command that can be used is S (stop).
The output mode can be changed with command FORM.
S
Stopping the measurement output
S
Ends the RUN state; after this command all other commands are available.
SEND
Outputting a reading once
SEND
or
SEND aa
in POLL mode
aa
=
address of the transmitter when more than one transmitter is
connected to a serial bus (0...99; set with command ADDR)
Outputs the current measurement readings via the serial line. The output for-
mat depends on which parameters the transmitter can output. Output types are:
"Td=999.9 'C",
"RH=999.9 %RH T=999.9 'C Td=9999.9 'C",
"Td=999.9 x=999.9 g/kg",
"RH=999.9 %RH T=999.9 'C Td=9999.9 'C a=9999.9 g/m3
x=9999.9 g/kg Tw=999.9 'C",
The output mode can be changed with command FORM.