User Manual

120 10503-201 PRELIMINARY T-96S Technical Manual
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3. In the idle mode, i.e. no transmission or
reception, RX Data will be held in the
idle (i.e. “marking”) condition.
4. When a valid radio data signal is re-
ceived, DCD will be asserted and data
will be delivered.
5. When the radio carrier is dropped, the
T-96H will clamp RX Data idle (mark-
ing) again and drop DCD. At 19200 b/s
a few extraneous bits may be delivered
after the carrier is dropped (sometimes
called “bit dribble”). User software
should take this possibility into account.
2.5.1 RTS/CTS Timing
The T-96H asserts CTS after RTS has been
asserted and a sufficient time has elapsed to
allow modem synchronization. The times
are fixed at the factory and are not user–
adjustable.
Repeater mode
(Extended time) must be set
(via the T96HRSS) if the unit is to commu-
nicate through a repeater.
Times are increased if
online diagnostics
are enabled, as shown in the columns
diag.
on
.
Table 3 - RTS / CTS Delays
RTS/CTS delay (normal) RTS/CTS delay (extended)
Speed diag. off diag. on diag. off diag. on
1200 b/s 50 ms 144 ms 80 ms 174 ms
2400 b/s 40 ms 87 ms 70 ms 117 ms
4800 b/s 30 ms 54 ms 60 ms 84 ms
9600 b/s 30 ms 41 ms 60 ms 71 ms
19200 b/s 30 ms 36 ms 60 ms 66 ms
2.5.2 XTAL mode
This mode extends all RTS/CTS delays by 5
ms for compatibility with earlier, crystal
controlled products (T-Modem 96, RNet
9600). Select this mode from the T96RSS.
2.5.3 Extended Turnoff
An end–of–transmission quiet period ap-
proximately 8 characters long can be in-
voked on the T-96H by holding its tranmit-
ter on briefly after RTS is dropped. This
quiet period, which occurs between the last
valid data character and any possible extra-
neous “noise” bits, may be of benefit to
some DTE
that would otherwise be adversely affected
by the extraneous bits. This quiet period is
selected via the T96RSS.
Table 4 - Extended Turnoff Delays
Speed Quiet “turnoff” period
1200 b/s 70 ms
2400 b/s 35 ms
4800 b/s 16 ms
9600 b/s 8 ms
19200 b/s 4 ms