Vaisala HMP228 - Manual (Page 109)

HMP228
M210282en-A Appendix 7: Alarm output unit
103
- the third parameter (in this example HI ON) starts blinking. This
parameter determines whether the alarm output is in use or not, and
when it is activated. The selection is acknowledged with ENT.
The options are the following:
- HI ON (the alarm is activated by exceeding the setpoint, the
output is in use)
- LO ON (the alarm is activated if the value goes below the
setpoint, the output is in use)
- HI OFF (the alarm is activated by exceeding the setpoint, the
output is not in use)
- LO OFF (the alarm is activated if the value goes below the
setpoint, the output is not in use)
- the setpoint starts blinking (in this example, -20.00); if you wish to
change it, press CL and enter the new setpoint
- the hysteresis value starts blinking (in this example, 5.00); if you
wish to change it, press CL and enter the new value
NOTE
The options HI OFF and LO OFF are used to deactivate
the relay outputs e.g. for service purposes.
The settings of the channel 2 are changed in the same way.
Setting and activating the outputs using an RS line
ALARM
or
ALARM n ON
where n = channel number (1 or 2)
The currently valid settings of the alarm output unit can be checked with
command ALARM:
>alarm
Ch1
aw LO OFF 0.000 0.000
Ch2 T LO OFF 0.000 0.000'C
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This is an example of the factory setting (both alarm outputs are in OFF mode,
i.e. not in use). The settings can be changed with command ALARM:
>alarm 1 aw HI .9 .1
Ch1 aw HI OFF 0.900 0.100
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