8 Commands and responses
8.4.4 Relay accessory
A Solid State Relay (SSR) accessory may be connected to the SQM-LU for generic use or for purposes of implementing
a dew-heater control. All commands (seen in table 8.19) to this accessory result in a response (seen in table 8.20).
Table 8.19: Relay accessory command summary
Command
Description
A4x
Get status of the relay accessory.
A40x
Deactivate the relay accessory. Also places the accessory into manual mode.
A41x
Activate the relay accessory. Also places the accessory into manual mode.
A4M
n
x
Set the mode of operation:
0=Light threshold activated.
1=Dewpoint activation.
2=Heat activated.
3-6=future use.
7=Manual mode where only the A40x and A41x commands affect the relay activation.
A4T
nn
x
Set the darkness threshold for relay activation. Where
nn
is the the darkness threshold.
The relay will be activated above this threshold.
Monitoring is perfomed once per second.
Table 8.20: Relay accessory response summary
Position
Example value
Description
0
A,
Confirmation of display accessory command.
1
4,
Accessory 3 (relay).
2
s
,
Status of device:
0 for deactivated relay.
1 for activated relay.
3
m
,
Mode of operation (where
m
=0-7):
0 = Light mode.
1 = Dewpoint mode.
2 = Heat mode.
7 = Manual mode.
4
nn
Threshold of darkness (in mpsas) for automatic mode of operation.
5
ttt
Temperature (
◦
C) used for dewpoint calculation.
6
hhh
Humidity (%RH) used for dewpoint calculation.
7
ddd
Dewpoint temperature (
◦
C) used for dewpoint calculation.
Carriage return (0x0d), Line feed (0x0a).
An example response to “
A2x
” is:
A,4,1,2,15,10,50,40,0
50
Unihedron SQM-LU Operator’s Manual -
20170728
Summary of Contents for SQM-LU
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