Command Mode; Enter Command Mode; Send At Commands - Digi XTend vB DigiMesh XTP9B-DPM-001 User Manual

Command mode

When data is transmitted from one node to another, the destination node transmits a network-level
acknowledgment back across the established route to the source node. This acknowledgment packet
indicates to the source node that the destination node received the data packet. If the source node does
not receive a network acknowledgment, it re-transmits the data.
Command mode
Command mode is a state in which the firmware interprets incoming characters as commands. Command
mode allows you to modify the device's firmware using parameters you can set using AT commands. When
you want to read or set any setting of the device, you have to send it an AT command. Every AT command
starts with the letters "AT" followed by the two characters that identify the command the device issues
and then by some optional configuration values. For more details, see Enter Command mode.

Enter Command mode

To get a device to switch into this mode, you must issue the string: +++ (by default). When the device sees
a full second of silence in the data stream followed by the string +++ (without Enter or Return) and
another full second of silence, it knows to stop sending data through and start accepting commands
locally.
Note Do not press Return or Enter after typing +++ because it will interrupt the guard time silence and
prevent you from entering Command mode.
Once you send the Command mode sequence, the device sends OK out the UART pin. The device may
delay sending the OK if it has not transmitted all of the serial data it received.
Once the device is in Command mode, it listens for user input and is able to receive AT commands on the
UART. If CT time (default is 10 seconds) passes without any user input, the device drops out of Command
mode and returns to Transparent operating mode.
You can customize the guard times and timeout in the device's configuration settings. For information on
how to do this, see CC (Command Sequence Character) on page 38, CT (Command mode Timeout) on page
38 and GT (Guard Times) on page 38.
Troubleshooting
Failure to enter Command mode is commonly due to baud rate mismatch. Ensure that the baud rate of
the connection matches the baud rate of the device. By default, the BD parameter = 3 (9600 b/s).

Send AT commands

Once the device enters Command mode, use the syntax in the following figure to send AT commands.
XTend vB DigiMesh RF Module User Guide 21