W
IRELESS
W
ATER
S
ENSOR
C
OPYRIGHT
©
2018,
R
ADIO
B
RIDGE
I
NC
.
W
IRELESS
W
ATER
S
ENSOR
P
AGE
8
OF
10
6.3.
Downlink Messages
The downlink message (web application to sensor) specific to the sensor configuration is
defined in following table. The common downlink messages are not included in this section
(see common messages document).
Table 7 Downlink Configuration Message 0x08
Byte Description
0
Disable Events (see table Disable Events Bit Definitions)
1
Threshold of relative resistance between probes (scale 0-255)
2
Restoral margin in units of relative resistance between probes
(scale 0-255)
The downlink configuration message for the sensor contains the resistance threshold for
detecting the presence of a liquid. Different liquids will have difference resistance, so this
threshold will need to be set based on the type of liquid that is being detected. The payload
from the event message can be used to find the relative resistance of a given liquid.
The bit definitions for the disable events field are defined below.
Table 8 Disable Events Bit Definitions
Byte Description
7:2
Not used
1
Disable water not present message (1 to disable, 0 to enable)
0
Disable water present message (1 to disable, 0 to enable)
An alert is sent when the relative measurement increases above the defined threshold. The
restoral margin requires that the measurement reduces by a certain amount below the
threshold before another alert is triggered. Both the threshold and restoral margin are in
units of relative resistance measurements on a scale of 0-255.
