•
Transceivermodefortransmissiononradiolink
•
Repeater mode to retransmitt incoming radio frame.
By default at power up, the modem is in transceiver mode: it is able to send or receive data to or from the radio
linkaccordingtoitscurrentconfiguration.
5.1.
Command mode
ThecommandmodeisusedtoreadandupdatethemodemconfigurationregistersusingATcommand.Incom-
mand mode the radio reception and transmission is inhibited.
Entering command mode:
The command mode is entered by issuing a +++ sequence on the serial link. The three consecutive + characters
areacceptedifnocharacterhavebeensentbeforeandafterthe+++sequenceforaminimaldurationdefinedby
theS214register.TheS214valueisdefinedinms.
Register S214
0
TIPS 1
The freeware "Hercules" terminal from
totransmitthe+++sequenceaccordingtothetimingrulesofS214bysendingatextfilewhichcontainthe+++
string.
TIPS 2
Exiting command mode (return back in transceiver mode): send the serial command : ATO <cr>
EASY CHECK
When receiving a right command, modem will answer:
•
'O'<cr>(ASCIIcharacter0x4f,0x0d)foracceptedcommand(meaningOK)
•
'E'<cr>(ASCIIcharacter0x45,0x0d)forerror(meaningERROR)
5.2.
Transceiver mode
In transceiver mode, two protocols are available:
•
Transparentprotocol
•
Addressedprotocol
The communication is always half-duplex. The radio transmission is processed prior to the radio reception (when
the transceiver is sending a radio frame, it is not able to decode any incoming radio frame).
If no data are sent on the serial link, the modem is waiting for radio reception. Each radio frame sent by another
modem is received and the data extracted from the radio frame are sent on the serial link. When the last charac-
ter has been sent on the serial link, it is possible to send an answer after the end of this last character.
All the data received on the serial link are encapsulated in a radio frame.
UG_ARF73 V1.7
Default value
240
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can help user
25