Unihedron SQM-LU, Operator'S Manual

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8.4 Accessories commands
8.4 Accessories commands
Some I
2
C accessory devices can be connected to the SQM-LU when using firmware feature version 44 and above. These
devices are connected by way of retrofitted wiring inside the unit or a future back panel connector.
All of the SQM-LU accessory commands begin with “A” (upper case).
8.4.1 Humidity / Temperture sensor
Two I
2
C humidity/temperature sensors models can be connected to the SQM-LU. All commands (seen in table 8.13) to
this accessory result in a response (seen in table 8.14).
Table 8.13: Humidity/temperature command summary
Command Description
A1Ex
Enable the humidity temperature accessory.
A1Dx
Disable the humidity temperature accessory.
A1M m x
Set the model number (where m =0-7) of the the humidity temperature accessory:
0=HIH8120
1=HYT939 (Sold by ControlEverything and others)
A1x
Report on the humidity temperature status.
Table 8.14: Humidity/temperature response summary
Position Example value Description
0
A,1,
Confirmation of humidity/temperature accessory command.
1
1,
Accessory 1 (Humidity/temperature sensor).
2
e ,
E for enabled.
D for disabled.
3
m ,
Model number (where m =0-7):
0=HIH8120
1=HYT939 (Sold by ControlEverything and others)
4
s
Status (0-3).
0 = Normal Operation, Valid Data that has not been fetched since
the last measurement cycle.
1 = Stale Data: Data that has already been fetched since the last
measurement cycle, or data fetched before the first measurement has
been completed.
2 = Sensor in Command Mode.
3 = Not used.
5 nnnnn Humidity(%RH) =
nnnnn
2
14
− 2
×
100%. 16383 when no connection.
6 nnnnn Temperature(
◦
C) =
nnnnn
2
14 −
2
× 165 − 40. 16383 when no connection.
Carriage return (0x0d), Line feed (0x0a).
An example response to “
A1x
” is:
A,1,E,1,0,07788,06202
Unihedron SQM-LU Operator’s Manual -
20170728
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