User's Manual

XTend™RFModule‐ProductManual
©2013DigiInternatonal,Inc. 18
AT Command Mode
To Enter AT Command Mode:
Default AT Command Mode Sequence (for transition to Command Mode):
• No characters sent for one second [refer to the BT (Guard Time Before) Command]
• Input three plus characters (“+++”) within one second
[refer to the CC (Command Sequence Character) Command.]
• No characters sent for one second [refer to the AT (Guard Time After) Command.]
All of the parameter values in the sequence can be modified to reflect user preferences.
To Send AT Commands:
Figure2‐09.SyntaxforsendingATCommands
To read a parameter value stored in the module register, leave the parameter field blank.
The preceding example would change the module’s Destination Address to "0x1F". To store the
new value to non-volatile (long term) memory, the Write (ATWR) command must subsequently be
sent before powering off the module.
System Response. When a command is sent to the module, the module will parse and execute
the command. Upon successful execution of a command, the module returns an “OK” message. If
execution of a command results in an error, the module returns an “ERROR” message.
To Exit AT Command Mode:
For an example of programming the RF module using AT Commands and descriptions of each config-
urable parameter, refer to the "RF Module Configuration" chapter [p20].
Binary Command Mode
Sending and receiving parameter values using binary commands is the fastest way to change
operating parameters of the module. Binary commands are used most often to sample signal
strength [refer to DB (Received Signal Strength) parameter] and/or error counts; or to change
module addresses and channels for polling systems when a quick response is necessary. Since the
sending and receiving of parameter values takes place through the same serial data path as 'live'
data (received RF payload), interference between the two types of data can be a concern.
Common questions about using binary commands:
• What are the implications of asserting CMD while live data is being sent or received?
1. Send the 3-character command sequence "+++" and observe guard times before and after
the command characters. [refer to ‘Default AT Command Mode Sequence’ below.] The ‘Ter-
minal’ tab (or other serial communications software) of the X-CTU Software can be used to
enter the sequence.
[OR]
2. Assert (low) the CONFIG
pin and turn the power going to the module off and back on (or
pulse the SHDN
pin).
[If the module is mounted to a Digi RS-232/485 Interface Board, the result can be achieved
by pressing the configuration switch down for 2 seconds.]
Send AT commands and parameters using the syntax shown below.
1. If no valid AT Commands are received within the time specified by CT (Command Mode
Timeout) Command, the module automatically returns to Idle Mode.
[OR]
2. Send ATCN (Exit Command Mode) Command.