COMMON MESSAGES
Wireless Acceleration Sensor User Guide
11
Chapter 4 – Common Messages
Common Messages
This chapter defines the protocol and message definitions common to all Reveal wireless sensors. Common
messages include basic error messages, tamper, supervisory, link quality, and downlink acknowledgments. Sensor
specific messages are in the
Sensor Specific Messages
chapter.
Message Protocol
This section defines the protocol and message definitions for the device.
Note:
MultiTech provides a web-based console at
for configuring and monitoring
devices. We recommend using this console rather than the protocols defined in this section.
If not using the console, use this topic to configure the device through downlink messages and decode the device
data.
Uplink Messages
The uplink messages (sensor to web application) have the following structure.
Item
Size
Description
Protocol Version
4 bits
A constant 1, provides extensibility to the specific format of a message type.
Packet Count
4 bits
A sequential number starting at 0 for the first message sent from the sensor to
the cloud. It increments by one for each subsequent message. When it reaches
0xF (15 decimal), it wraps back to 0. Packet count helps identify when a message
is lost. For example, if the packet count goes 2,4 instead of 2,3,4, it indicates a
message has been lost. It can also help identify out-of-order or duplicate
messages.
Message Type
1 byte
Byte format is 8 bits, with 256 combinations possible.
Message Payload
0-7 bytes Each message type has between 0 and 8 bytes of payload data specific to the
sensor. Refer to the following table for payload information.
Message
Payload
Description
0x00
5-byte reset code
Device has reset. The reset cause is represented in the 5-byte
reset code payload.
0x01
>3 (9)
Daily supervisory message (1-2 per day). The 3-byte payload
contains current sensor status. Refer to
for payload details.
0x02
1-byte event
A tamper event has occurred. Refer to
for
details.
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Sensor event
Sensor events are defined in the
Sensor Specific Messages
chapter.
