
FIRMWARE DESCRIPTION
Data Mode
2.10
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19.01.2007
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3.3.4.3 Interworking of Modem lead Signals
In transparent data mode the modem lead signals are available on the DTRI, DSRO, DCDIO
and RIIO pins.
DTRI, DCDIO and RIIO signals are interworked to the peer module. DTRI is always
interworked to DSRO. DCDIO and RIIO are interworked to DCDIO and RIIO respectively.
Interworking RIIO and DCDIO requires that one module is configured in DTE mode and the
peer module in DCE mode. In case both peers are configured in DCE mode, RIIO and
DCDIO outputs remain inactive. In case both peers are configured in DTE mode the RIIO
and DCDIO input signals are ignored.
Note: DTRI, DSRO and RIIO are also used for call control purpose. This function may
overload the normal functions of these signals in certain situations. See section 3.3.4.4 for
details.
The DECT protocol transmits modem lead signals such that only changes of these signals
are signalled. When the module detects a change at any of its modem lead inputs it will
transmit a dedicated message to its peer.
The maximum transmission rate is one message every 10ms. Hence at the receiving side
the lines are updated in 10ms intervals. This effect causes certain changes to the signal
timing. Moreover, due to internal pipelining the timing between data bytes sent over the RS-
232 interface and modem lead signal changes is not preserved. This must be taken into
account in certain applications.
3.3.4.4 Call
Control
Call control uses the modem lead signals DTRI, DSRO and RIIO. The call control function is
multiplexed with the regular usage of these signals.
An outgoing call is a call that originates from the PT.
An incoming call is a call that originates from the FT.
Please also refer to SPECC command.