Vaisala HMP230 - Manual (Page 47)

HMP230 SERIES
M210225en-B User's Guide
41
6.3.5.4. Selecting the output units
• Select Unit in the main menu:
• Use the arrow keys to select the right alternative and press ENT.
quantity metric non-metric
RH = relative humidity %RH %RH
T = temperature °C °F
Td = dewpoint temperature °C °F
a = absolute humidity g/m 3 gr/ft 3
x = mixing ratio g/kg gr/lb
h = enthalpy kJ/kg Btu/lb
Tw = wet bulb temperature °C °F
6.3.5.5. Selecting the calculation mode
Disconnect the security lock jumper!
•
Select More and then again More in the second menu:
•
Select Frost and then the desired alternative with the arrow keys;
FROST ON for frostpoint and FROST OFF (default) for dewpoint
calculation at dewpoint temperatures below 0
°
C.
6.3.6. Output modes
The output modes only affect output through the serial interface: the transmit-
ter accepts all display and LED commands irrespective of which serial output
mode it is in. The HMP230 transmitters have three serial output modes: RUN,
STOP and POLL.
In the RUN state the transmitter outputs measurements automatically through
the serial interface to a PC or a peripheral. The only command that can be
given through the serial interface is S (stop), which ends the RUN state.
In the STOP state serial commands are given to the transmitters. Measure-
ments are then output only by entering command SEND.
The POLL state is used when more than one transmitter is connected to the
same serial bus; a single transmitter can be addressed and communicated with.
When the connection to the one transmitter is opened in the POLL state, the
transmitter goes into STOP state and can receive commands normally. Closing