Chapter 4
Signal Connections
©
National Instruments Corporation
4-3
Digital 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 operate in RSE mode,
you must connect VIDEO0– to GND. When you use or VIDEO0–,
you must disconnect the video signal from the BNC connector. To operate in
DIFF mode, remove attached W1 jumper.
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 IMAQ 1410 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.
HSYNCIN±
Use HSYNCIN± when the IMAQ 1410 is in external lock mode or external
HSYNC/VSYNC (HLOCK only) 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 for 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 IMAQ 1410 is in external lock mode or external
HSYNC/VSYNC (HLOCK only) 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 IMAQ 1410 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 IMAQ 1410 generates CSYNCOUT.