VXC-112(i)(A)U/142(i)AU/182i(A)U/114(iA)U/144(i)U, VEX-114(i)/144(i) , VEX-112(i)/142(i) User’s Manual (Ver. 1.5
Aug.10 2012) -----56
4.5. Customized Baud Rate
To generate baud rate 125,000 bps:
125,000 * 16 * 8 = 16,000,000 = 16 MHz crystal
So, when you use a 16 MHz crystal to replace the built-in 14.7 MHz crystal (for U versions
VXC cards) and select the baud rate 115,200 bps in your software setting, the hardware will
generate baud rate 125 kbps actually.
To generate baud rate 250,000 bps:
250,000 * 16 * 4 = 16,000,000 = 16 MHz crystal
(Baud rate * 16 x clock * Divisor = Crystal Clock Frequency)
Thus, when you use a 16 MHz crystal to replace the built-in 14.7 MHz crystal (for U versions
VXC cards) and select the baud rate 230,400 bps in your software setting, the hardware will
generate baud rate 250 kbps actually.
Note: The multi-port serial cards can have a special baud rate in OEM version. Please
contact us for more information regarding the OEM products.
Note
: External 14.7 MHz crystal can be customized to replace (for U versions VXC cards),
but VEX cards (PCI Express) can’t.
Warning:
The baud rates higher than 115,200 bps are not guaranteed to work.
