Vaisala HMP228 - Manual (Page 75)

HMP228
M210282en-A Appendix 2: Display commands
69
• Pressing ENT returns the programme to the main menu.
• Pressing CL deletes the old address; enter the new address with the
arrow keys.
1.1.1.4 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
aw (aw) (aw)
T °C °F
1.1.2 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 HMP228 transmitter has 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 then receive commands normally.
Closing the connection returns the transmitter to POLL state. In POLL state
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. If the transmitter has a display, the settings can be checked through it.