Vaisala PTB220 - Manual (Page 49)

C HAPTER 6________________________________________________________________ OPERATING
V AISALA _________________________________________________________________________ 43
CHAPTER 6
OPERATING
Only a few commands are needed to operate a PTB220 barometer in
the RUN, STOP and POLL modes. In the SEND mode and in the
PULSE mode no commands are needed.
In the RUN or STOP modes the commands R, S and SEND can be
used. The user may also use his own SEND command if he has
previously specified one using the SCOM command (see Chapter
Software settings).
In the POLL mode, the barometer responds to a SEND command only
if it includes the address of the barometer. OPEN and CLOSE
commands are also available for temporary communication with one
single barometer.
In the SEND mode, no commands are needed. The barometer will
automatically output one message at power-up, or when triggering the
barometer on using pin 4 of the barometer.
In the PULSE mode, the barometer requires a trigger pulse from the
host system. In this case, the barometer must be powered-up
separately and the pulse trigger signal must be given to the barometer
after the settling time has elapsed.
RUN and STOP modes
T ABLE 6-1 summarizes the commands that are used in the RUN and
STOP modes. In addition, the user may use his own SEND command
if he has previously specified one with the SCOM commissioning
command. The commands are not case sensitive except for the SCOM
command.