XLR PRO operational design
XLR PRO Radio Frequency (RF) Modem User Guide
25
If the above conditions do not apply, then you may prefer transparent operation due to the simplicity of operation.
You can use a mixture of devices running API Mode and Transparent Mode in a network.
AT Command Mode
To modify or read radio parameters, the XLR PRO must first enter Command Mode - a state in which incoming serial
characters are interpreted as commands. When the XLR PRO is configured for API mode, AT Commands can be issued
locally or remotely using the appropriate API frames. For more information on configuring the XLR PRO using API
frames, refer to
on page 50. While in API mode, AT command mode can still be entered using
the command sequence listed below.
Entering AT Command Mode
1
Send the three-character command se++ (three plus signs).
2
Observe the guard times before and after the command characters. Refer to “Default AT Command Mode
sequence” below.
Default AT Command Mode sequence for transition to Command Mode:
•
No characters sent for one second [Guard Times (GT) parameter = 0x3E8].
•
Input three plus characters (+++) within one second [Command Sequence Character (CC) parameter = 0x2B].
•
No characters sent for one second [GT parameter = 0x3E8].
Once the AT command mode sequence has been issued, the XLR PRO sends an "OK\r" out of the active serial
interface. The "OK\r" characters can be delayed if the XLR PRO has not finished transmitting received serial data.
When command mode has been entered, the command mode timer is started (CT command), and the XLR PRO is able
to receive AT commands on the active serial interface.
All of the parameter values in the sequence can be modified to reflect user preferences.
Note
Failure to enter AT Command Mode is most commonly due to baud rate mismatch. By default, the Baud Rate
(BD) parameter = 3 (9600 b/s).
Sending AT commands
Use the following syntax to send AT commands and parameters:
To read a parameter value stored in the XLR PRO’s register, omit the parameter field.
The preceding example would change the destination address (low) to “0x1F”. To store the new value to non-volatile
(long term) memory, send the Write (WR) command. This allows modified parameter values to persist in the module’s
registry after a reset. Otherwise, parameters are restored to previously saved values after a reset.
Example: ATDL 1F<CR>
“AT”
Prefix
ASCII
Command
Space
(optional)
Parameter
(optional, HEX)
Carriage
Return