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© Sealevel Systems, Inc. 3543 Manual | SL9119 9/2022
Clock Modes
The
SIO4-104.485
utilizes a 14.7456 MHz oscillator. This is eight times faster than the standard COM: port
oscillator, which typically is 1.8432 MHz. This allows the adapter to achieve a maximum data rate of
921.6Kbps. The following sections outline the baud rate calculations and instructions for achieving your
desired baud rate.
Baud Rates and Oscillator value
The following table shows some common data rates and the rates you should choose to achieve them
when using the
SIO4-104.485
. If the O/S of choice is Windows 95/98/ME/2000/NT/XP, the oscillator value
(14.7456 MHz) should be entered into the ‘Advanced Tab’ on 95/98/Me/2000/XP Device Manager applet.
Typically this is done automatically when the Sealevel Software driver is loaded.
When using Windows NT, the ‘Advanced Ports’ applet in the Control Panel should be launched and the
oscillator value entered manually in the ‘Advanced’ tab, or all data rates will be eight (8) times the selected
rate. For example if a data rate of 19.2Kbps is selected, the actual data rate will be 153.6Kbps.
When using any other OS (i.e. Linux, or QNX) the following table should be used.
For this Data Rate
Choose this Data Rate
1200 bps
150 bps
2400 bps
300 bps
4800 bps
600 bps
9600 bps
1200 bps
19.2K bps
2400 bps
57.6 K bps
4800 bps
115.2 K bps
14.4K bps
230.4K bps
28.8K bps
460.8K bps
57.6 K bps
921.6K bps
115.2 K bps
