Product manual
9XTend‐PKG‐R™RS‐232/485RFModem–ProductManualv1.2.4
©2005MaxStream,Inc.ConfidentialandProprietary 18
3.2.6. Command Mode
To set or read modem parameters; the modem must first enter Command Mode (a state in which
incoming characters are interpreted as commands). Two command types are available:
• AT Commands
• Binary Commands
For modified parameter values to persist in the modem’s registry, changes must be saved to non-
volatile memory using WR (Write) Command. Otherwise, parameters are reset to previously
stored values after the modem is powered off and then on again.
AT Command Mode
To enter AT Command Mode:
1. Send the 3-character command sequence “+++” and observe guard times before and after
the command characters. [See “Default AT Command Mode Sequence” below.]
Use the “Terminal” tab (or other serial communications software) of the X-CTU Software to
enter the sequence.
[OR]
2. Force entrance into AT Command Mode by keeping the configuration switch [Figure 1-01a,
p6] pressed for two seconds.
Default AT Command Mode Sequence:
• No characters sent for one second [see BT (Guard Time Before) Command]
• Input three plus characters (“+++”) within one second [see CC (Command Sequence
Character) Command.]
• No characters sent for one second [see AT (Guard Time After) Command.]
To Send AT Commands to the RF Modem:
Figure3‐08. SyntaxforsendingXTendATCommands
NOTE: To read a current parameter value stored in a register, leave the parameter field blank.
The preceding example would change the modem Destination Address “1F”. To store the new
value to the modem’s non-volatile (long term) memory, use the WR (Write) Command.
The “Modem Configuration” tab of the X-CTU Software [p22] provides a software user interface
that facilitates the programming of RF modems. A more in depth look at modem programming is
in the Advanced Configuration section [p20].
To Exit Command Mode:
1. If no valid AT Commands are received within the time specified by CT (Command Mode
Timeout) Command, the modem automatically returns to Idle Mode.
[OR]
2. Send ATCN (Exit Command Mode) Command.
For an example on that illustrates programming the modem using AT Commands, refer to the
‘Terminal tab’ section on p21.