Chapter 4
Signal Connections
©
National Instruments Corporation
4-3
I/O Connector Signal Connection Descriptions
Table 4-1 describes each signal connection on the 68-pin VHDCI
connector.
Table 4-1.
I/O Connector Signals
Signal Name
Description
VIDEO0±
VIDEO0± allows for a DIFF or RSE connection to video channel 0. To operate
in RSE mode, connect VIDEO0– to GND. When you use or
VIDEO0–, you must disconnect the BNC connector.
VIDEO<3..1>±
VIDEO<3..1>± allows for a DIFF or RSE connection to video channels
1, 2, and 3. To operate in RSE mode, connect VIDEO– to GND.
PCLKIN±
Use PCLKIN± when the 1409 device is in external lock mode. In this mode,
PCLKIN represents the A/D sampling clock. You can select PCLKIN to be
either TTL or RS-422 mode and program its polarity through software. In
RS-422 mode, both and PCLKIN– receive the PCLK signal.
PCLKOUT±
Use PCLKOUT± when your camera requires an external pixel clock source.
The 1409 device can generate variable pixel clock frequencies between
500 kHz and 40 MHz. You can set PCLKOUT± through your software in TTL
and RS-422 modes.
HSYNCIN±
Use HSYNCIN± when the 1409 device is in external lock mode. HSYNC is a
synchronization pulse produced at the beginning of each video scan line that
keeps a video monitor's horizontal scan rate in step with the transmission of
each new line. You can set HSYNCIN to be either TTL or RS-422 mode and
program its polarity through software. In RS-422 mode, both and
HSYNCIN– receive the HSYNC signal.
VSYNCIN±
Use VSYNCIN± when the 1409 device is in external lock mode. VSYNC is a
synchronization pulse generated at the beginning of each video frame that tells
the video monitor when to start a new field. You can set VSYNCIN to be either
TTL or RS-422 mode and program its polarity through software. In RS-422
mode, both and VSYNCIN– receive the VSYNC signal.
CSYNCIN±
Use CSYNCIN± when the 1409 device is in CSYNC external mode. CSYNC
is a signal consisting of horizontal sync pulses, vertical sync pulses, and
equalizing pulses only. You can set CSYNCIN to be either TTL or RS-422
mode and program its polarity through software. In RS-422 mode, both
and CSYNCIN– receive the CSYNC signal.
CSYNCOUT
CSYNCOUT is a TTL output of the internal CSYNC signal. In CSYNC
external mode, CSYNCOUT maps directly to CSYNCIN. In standard mode,
the synchronization circuitry of the 1409 device generates CSYNCOUT.
