06-06-V6-smn
p8
Half duplex transmission
This modem has 2 working modes:
¾
Transparent mode, without flow control. When transmitting, data received from the
serial link are transmitted on the radio link. When data are received on the radio link,
these data are sent on the serial link.
¾
Addressed mode, with flow control (see register S216)
In these modes, the frame transmission always start on the following conditions:
•
Detection of a silence on the serial link, greater than S217, after the reception of the
latest character.
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Or when the number of received characters from the serial link is greater or equal to
the maximum radio frame size (S218).
•
Addressed mode
In transmission mode, data received on the serial link are sent on the radio link with
the following format:
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Frame format: <preamble><synchro><Address> DATA <postambule>. Preamble,
synchronisation and postambule are used for the radio reception.
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The Address field is set up with S256 (destination address) value (LSB first).
In reception mode: The <Address> field of the radio frame is checked with the local
address (S252)
•
If the addresses match, DATA (and only DATA) are transmitted on the serial link,
otherwise received data are silently discarded.
•
Serial commands
¾
They are used to configure the modem parameters or read the modem set-up.
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They are sent during the modem mode. They aren’t sent on the radio link.
¾
A SLSTRING is interpreted as a command only if a silence is present before (see
<silenced>) the SLSTRING and after (see <silencef>) the SLSTRING. Otherwise the
string is not interpreted as a command, and therefore it is sent on the radio link.
Serial Command format: <silenced>SLSTRING<silencef> with
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<silenced>: silence before the command, more than 3 characters (see S214).
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SLSTRING, serial command, always starting with the characters SL. (Example SLI
for displaying modem registers)
•
<silencef> : end silence, more than 3 characters (see S214)
The answer to a SL command could be:
•
the string OK
Î
command executed successfully
•
The string ERROR (syntax error, unknown command…)
•
a specific string according to the requested information
Sending a serial command using a terminal: see chapt.
Sending a serial command using
HYPERTERMINAL
WORKING MODE
