Vaisala HMP230 - Manual (Page 144)

HMP230 SERIES
Appendix 7: Alarm output unit
M210225en-B
138
The currently valid settings of the alarm output unit can be checked with
command ALARM:
>alarm<cr>
Ch1
RH LO OFF 0.00 0.00 %RH
Ch2 RH HI OFF 100.00 0.00 %RH
>
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 Td HI -20 5
Ch1 Td HI OFF -20.00 5.00 'C
Ch2 RH HI OFF 100.00 0.00 %RH
>
When giving this command, first enter the channel number i.e. the number of
the alarm output you wish to use (1 or 2). Then select the quantity you wish to
have on that channel:
RH = relative humidity
T = temperature
Td = dewpoint temperature
abs = absolute humidity
mix = mixing ratio
Tw = wet bulb temperature
h = enthalpy.
The third parameter (HI/LO) determines whether the alarm is activated when
the setpoint value is exceeded (HI) or not reached (LO). The fourth parameter
is the actual setpoint value which activates the alarm. The last parameter is the
hysteresis value; it indicates how much the measured value has to exceed or
go below the setpoint before the alarm is deactivated. If the third parameter is
HI, the alarm is deactivated when the measured value goes below the setpoint
with the chosen hysteresis value; if the parameter is LO, the alarm is
deactivated when the measured value exceeds the setpoint with the chosen
hysteresis value.
When the alarm outputs have been set, you can activate the outputs with
commands ALARM 1 ON (channel 1) or ALARM 2 ON (channel 2). Note that
you can also activate the outputs when giving other parameters with command
ALARM.
Examples of activating the outputs:
with command ALARM:
>alarm 1 Td HI -20 5
Ch1 Td HI ON -20.00 5.00 'C
Ch2 RH HI ON 100.00 0.00 %RH
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