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17
Happy Flow
• In data-mode the unit starts looking for the Es-
cape-sequence if there is no data from DTE (Data
Terminal Equipment) for more than 20 ms (Start
Guard Time).
• If the unit detects the Escape-Sequence:
• The transmitter continues sending over the air
the data received from DTE before Escape- Se-
quence and buffers the data from DTE;
• The Receiver immediately stops forwarding to
DTE the data received over the air and buffers it
instead.
• The radio unit waits for 20 ms and then sends Es-
cape-Acknowledge to DTE if there is no data from
DTE during 20 ms of Stop Guard Time.
• 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.)
Hardware Switching to Command
Mode
As alternative to Software Switching, the switching
through the MP/DP (Data Terminal Ready, DTR) con-
trol 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 ac-
knowledge 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.
Switching to Data Mode
• DTE sends the CLI command “DATA-
MODE<CR><LF>” to the unit.
• Unit answers with Escape-Acknowledge
(„@00<CR><LF>“) and immediately goes to data-
mode, so that the DTE can start sending data as
soon as the Escape-Acknowledge has been re-
ceived.
• If no valid CLI commands received from DTE
within 1 minute, the unit will automatically switch
back to data-mode.
CONNECT
To connect the radio unit through the local main-
tenance serial port or to establish the link with the
remote unit in the Point-to-Multipoint network, the
CONNECT command must be used.
CONNECT [Unit_Numb] [/?]
Where the Unit_Numb is an assigned decimal num-
ber for the unit to be connected. To get the complete
unit list, the CONNECT command must be used with
no parameter :
Unit Serial Number
Connect
BS
003578659922
1
003574459923
C
To disconnect from the remote unit and connect to
the local unit, the parameter (Unit_Numb) must be
equal to 0x00.
LINK
The LINK command is responsible for configuring ra-
dio’s operation mode. It has six parameters listed be-
low.
LINK [Parameter Name] [Parameters List] [/?]
Networking Commands
