LI-COR LI-7820, Инструкция по эксплуатации

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Section 7. Communication with the MQTT protocol
Setting the zero calibration
This tutorial publishes to the
cfg
topic. Publishing is described in detail at
mosquitto.org/man/mosquitto_pub-1.html. Select a quality gas and plumb it zero
gas to the analyzer air inlet, letting the excess pressure vent to the room.
1
To start a zero calibration, enter:
mosquitto_pub -h 172.24.82.41 -t
"licor/niobrara/cfg/Start_Peak_Base_Line_Cal" -m
l
mosquitto_pub
launches the application to publish (send to the instrument).
l
-h
specifies a host (the Trace Gas Analyzer) followed by the instrument IP
address
l
172.24.82.41
is the IP address. You can also enter the host name. Both are
given on the instrument display.
l
-t
specifies that you want to subscribe to a topic.
l
"licor/niobrara/cfg/Start_Peak_Base_Line_Cal"
is the topic and hier-
archy.
l
-m
specifies that you are sending a message from the command line.
l
"1"
is the message.
This command initiates the baseline calibration. The process takes several minutes
(up to 5 minutes). Wait until the process is finished before moving on to other
commands.
2
To check if the zero is complete, enter the command:
mosquitto_sub -h 172.24.82.41 -t
"licor/niobrara/cfg/Start_Peak_Base_Line_Cal
The instrument will reply with
"0"
.
3 Type
Ctrl + C
to stop the script.
7-4 LI-7820 N₂O/H₂O Gas Analyzer