Vaisala HMP260 - Manual (Page 34)

HMP260 SERIES
Operating Manual
HMP260-U017en-1.5
28 1997-11-25
5.3.5.4 Selecting the output units
• Select Unit in the main menu:
• Use the arrow keys to select the right alternative and press ENT.
metric non-metric
RH %RH %RH
T °C °F
Td °C °F
a g/m 3 gr/ft 3
x g/kg gr/lb
Tw °C °F
5.3.6 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 HMP260 transmitters have three serial output modes: RUN,
STOP and POLL.
In the RUN mode 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 mode.
In the STOP mode serial commands are given to the transmitters. Measure-
ments are then output only by entering command SEND.
The POLL mode 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 a given transmitter is opened in the POLL mode, the
transmitter goes into STOP mode and can then receive commands normally.
Closing the connection returns the transmitter to POLL mode. In POLL mode
the transmitter outputs measurement only when requested (command SEND
aa). If the user has forgotten the address of the transmitter and the transmitter
does not have a display, the transmitter has to be reverted to the factory set-
tings (see Chapter 4.3.1). If the transmitter has a display, the settings can be
checked through it.