Dear JG,
I'm posting the results of our e-mail discussions from the service request you created for the forum:
I've
been checking on a couple of the parameters in the file you sent me to
see if you will actually be able to acquire the RS-343 signal. I
thought it was going to be OK, but based upon the Pixel Frequency
listed (68.464286 MHz), it won't be possible. The PCI-1410 has a
maximum PCLK frequency of 40MHz, which won't be sufficient to acquire
your signal.
The following is an example with numbers from
the RS-170 standard. I did the same PCLK calculation with your numbers to verify:
Parameters of interest:
# of lines/frame: 525 (this includes 485 lines for display; the rest are VSYNC lines for each of the two fields)
line frequency: 15.734 kHz
line duration: 63.556 microsec
active horizontal duration: 52.66 microsec
# active pixels/line: 640
Now, some calculations we can make:
Pixel clock (PCLK) frequency (the frequency at which each pixel arrives at the frame grabber):
640 pixels/line / 52.66 e-6 sec/line = 12.15 e6 pixels/sec (12.15 MHz)
Total line length in pixels of active video + timing information (referred to as HCOUNT):
63.556 e-6 sec * 12.15 e6 pixels/sec = 772 pixels/line
Frame rate:
15.734 e3 lines/sec / 525 lines/frame = 30 frames/sec
Best Regards
~NH
