Table of Contents
Advertisement
XBee API mode
Receive success/failure status of each transmitted packet.
n
Obtain the signal strength of any received packet.
n
Perform advanced network management and diagnosis.
n
Perform advanced functions such as remote firmware update, ZDO, ZCL and so on.
n
API frame structure
The structured data packets in API mode are called frames. They are sent and received through the
serial interface of the device and contain the wireless message itself as well as some extra
information such as the destination/source of the data or the signal quality.
When a device is in API mode, all data entering and leaving the module through the serial interface is
contained in frames that define operations or events within the device.
An API frame has the following structure:
Start
delimiter
1
0x7E
Note
MSB represents the most significant byte, and LSB represents the least significant byte.
Any data received through the serial interface prior to the start delimiter is silently discarded by the
XBee. If the frame is not received correctly, or if the checksum fails, the data is also discarded and the
module indicates the nature of the failure by replying with another frame.
Start delimiter
The start delimiter is the first byte of a frame consisting of a special sequence of bits that indicate the
beginning of a data frame. Its value is always 0x7E. This allows for easy detection of a new incoming
frame.
Length
The length field specifies the total number of bytes included in the frame data field. Its two-byte value
excludes the start delimiter, the length, and the checksum.
Frame data
This field contains the information received or to be transmitted. Frame data is structured based on
the purpose of the API frame:
XBee-PRO 900HP DigiMesh Kit User Guide
Length
2
3
4
5
MSB
LSB
Frame data
6
7
8
9
...
API-specific structure
API frame structure
Checksum
n
n+1
Single byte
40
Advertisement
Table of Contents
