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FASTCOM SERIAL SETTINGS
CLOCK/4
Clock divisors of 1 and 4 are available. Clearing the checkbox selects a divisor of 1 and setting the checkbox
selects a divisor of 4. It is best to leave this box unchecked.
Auto 485
When checked, OUT1 of the UART becomes a 485 driver control signal, enabling automatic tri-state control.
You must check 485 Enable and uncheck Enable Source for this to work.
RX Trigger
Determines the number of bytes that will be stored in the receive FIFO on the 16C850 before an interrupt is
triggered. Valid values are from 1 to 128 bytes. The optimal setting is 64 bytes. For 16C550 compatibility,
set to 8.
TX Trigger
Determines the number of bytes remaining in the transmit FIFO on the 16C850 before an interrupt is
triggered. Valid values are from 0 to 127 bytes. The optimal setting is 64 bytes. For 16C550 compatibility,
set to 0.
TX Write Size
Determines the number of bytes sent to the board at a time. Valid values are from 1 to 128. This number
plus the TX Trigger value should not exceed 128. The optimal value is 64. For 16C550 compatibility, set to
16 or 1.
CTS Disable
When checked, the CTS signal is forced active, ignoring the signal from the connector. When unchecked, the
CTS signal is read from the connector.
485 Enable
When checked, the 485 driver mechanism is enabled.
RX Echo Disable
When checked, the receive is disabled during transmit.
Enable Source
•
When checked, the 485 driver control is RTS. This is compatible with older boards and software which
are not automatically controlled by hardware. Uncheck Auto 485.
•
When unchecked, the 485 driver control is OUT1 on the UART. This is compatible with hardware control
of automatic 485 mode. Check Auto 485.
BaudTable (Win2K/XP)
This table represents the standard baud rates that the Fastcom card will currently support. If you wish to use
a non-standard baud, you may enter it into one of the boxes on the table and hit the tab key
(do not hit enter,
hitting enter will exit the program). This will set the onboard clock generator to a frequency (see Input
Frequency below) that will divide down to the new baud rate. The rest of the table will also be updated to
reflect other bauds that can be used with the calculated clock frequency. If you wish to return to the standard
rates, you can set the top box to 115200 and hit tab and the rest of the bauds will be filled in.
Note: The baud rates that you set will not be available to standard Windows applications like HyperTerminal.
The new rates will be available to you in your code or in applications that allow user defined baud rates such
as TTY2, which can be found on the Fastcom disk (Fastcom_CD\Fastcom_disks\AsyncPCI\tty\tty2.exe).
THIS SETTING=THIS BITRATE (Baud Rate Substitution Table) (Win 98/NT)
Under THIS SETTING you will see the standard PC baud rates, from 115.2K to 300. If you wish to use a