COMMON MESSAGES
Wireless Acceleration Sensor User Guide
13
Supervisory Message 0x01
Wireless sensors periodically send a supervisory message so the backend system can verify the device is still alive
and report error conditions. The supervisory message payload include current sensor status.
You can also trigger a supervisory message. To do this:
Place a magnet near the triangular notch on the side of the sensor.
The following table shows the supervisory message payload:
Bytes
Description
0
Supervisory error codes as follows:
Bits
Description
7:5
Not used.
4
Tamper detected since last reset.
3
Current tamper state.
2
Error with last downlink.
1
Battery low (under 2.8v).
0
Radio communication error, communication with the integrated radio failed and the
device was reset.
1
Current sensor state, 1-byte. This is device specific, refer Sensor Specific Messages chapter for details.
For other devices, use the periodic reporting feature.
2
Battery level is a two-digit battery voltage. For example, if the battery voltage is 2.9V, byte 2 would be
0x29.
3-6
Extended sensor state, 4-bytes. Allows sensors with higher precision or multiple values to report
during a supervisory event. For other devices, use the periodic reporting feature.
7-8
Event accumulation count is the number of sensor events since the last supervisory message. To
improve battery life, can be used with the
Disable all sensor events
setting so only an event total is
reported during a supervisory message, individual events are not reported as they occur. This feature
is available in firmware v2.0 and beyond.
Tamper Message 0x02
A sensor sends a message when the tamper switch has been opened or closed through either an enclosure tamper
or a wall mount tamper. The tamper message contains a 1-byte payload as shown in the following table.
Payload
Description
0x00
Tamper switch opened.
0x01
Tamper switch closed.
Link Quality Message 0xfb
The link quality message provides a signal strength and a signal to noise measurement at the device itself. The link
quality message payload is shown in the following table.
