API frames
User Data Relay - 0x2D
Digi XBee3 Cellular LTE-M/NB-IoT Global Smart Modem User Guide
225
User Data Relay - 0x2D
Description
Allows for data to be sent to an interface with a designation of a target interface for the data to be
output on. The frame can be sent or received from any of the following interfaces: MicroPython
(internal interface), UART, and BLE. This frame is used in conjunction with
You can send and receive User Data Relay Frames from MicroPython. See
in the
MicroPython Programming Guide
.
Format
The following table provides the contents of the frame. For details on frame structure, see
Field
name
Field
value
Data
type
Description
Frame type 0x2D
Byte
Frame ID
Reference identifier used to match status responses.
0
disables the
TX Status frame. There is no TX Status frame for sucess.
Destination
interface
Byte
0 = Serial port (SPI, or UART when in API mode)
1 = BLE
2 = MicroPython
Data
Variable
Checksum
1 Byte
Error cases
The Frame ID is used to report error conditions in a method consistent with existing transmit frames.
The error codes are mapped to statuses. The following conditions result in an error that is reported in
a TX Status frame, referencing the frame ID from the 0x2d request.
n
Invalid interface
(0x7c) : The user specified a destination interface that does not exist.
n
Interface not accepting frames
(0x7d): The destination interface is a valid interface, but is not
in a state that can accept data. For example UART not in API mode, BLE does not have a GATT
client connected, or buffer queues are full.
Example use cases
These examples show you can use this frame.
n
You can use the frame to send data to an external processor through the XBee UART/SPI via
the BLE connection. Use a cellphone to send the frame with UART interface as a target. Data
contained within the frame is sent out the UART contained within an Output Frame. The