User Manual

Command Line Interface
Command Line Interface Convention
25www.javad.com
Happy Flow
1. In data-mode the unit starts looking for the Escape-sequence if there is no data from DTE (Data
Terminal Equipment) for more than 20 ms (Start Guard Time).
2. If the unit detects the Escape-Sequence:
• The transmitter continues sending over the air the data received from DTE before Escape-
Sequence and buffers the data from DTE;
• The Receiver immediately stops forwarding to DTE the data received over the air and buffers it
instead.
3. The radio unit waits for 20 ms and then sends Escape-Acknowledge to DTE if there is no data
from DTE during 20 ms of Stop Guard Time.
4. The unit goes to command mode and discards Escape-Sequence from input buffer. The modem is
immediately ready to receive commands. At the same time it continues buffering the data received
over the air since step 2.
Escape-Sequence in Data
During its waiting in step 3, the unit receives data from DTE:
• The unit sends buffered Escape-Sequence from DTE to the air;
• The unit sends all buffered data received from the air since step 2 to DTE and stays in data-mode
(i.e. transmits data received from DTE over the air – including the just received, unexpected, data
and forwards data received over the air to DTE.)
1.2. Hardware Switching to Command Mode
As alternative to Software Switching, the switching through the MP/DP (Data Terminal Ready, DTR)
control line can be used. To set Command Mode, the DTE must assert DTR signal active and then
passive. By falling edge of DTR signal the unit goes to command mode and then sends Escape-
Acknowledge to DTE (“@00<CR><LF>”).
20 ms toggling on CTS control line needed to acknowledge switching from Data to Command mode and
vice versa.
Note:
The powered up radio modem by default goes to Data Mode regardless of DTR control line polarity.
1.3. Switching to Data Mode
• DTE sends the CLI command “DATAMODE<CR><LF>” to the unit.
• Unit answers with Escape-Acknowledge („@00<CR><LF>“) and immediately goes to datamode,
so that the DTE can start sending data as soon as the Escape-Acknowledge has been received.
• If no valid CLI commands received from DTE within 1 minute, the unit will automatically switch
back to data-mode.