Chapter 5
Configuration Utility
PCI/PXI-1408 and NI-IMAQ for Win95/NT
5-8
©
National Instruments Corporation
•
Chroma Filter—The 1408 device includes optional
antichrominance filters to use with NTSC and PAL video signals.
The three options for the color filters are as follows:
–
None—The antichrominance filter is disabled.
–
NTSC—The antichrominance filter is enabled for
NTSC-coded signals. The filtering is implemented by
a 3.58 MHz notch filter.
–
PAL—The antichrominance filter is enabled for PAL-coded
signals. The filtering is implemented by a 4.43 MHz notch
filter.
•
Acquisition Window—The acquisition window determines the
window offset and window size of the start of the video frame as
well as the number of active horizontal pixels and active lines.
•
Gain—The 1408 device has three programmable gain values: 1,
1.33, and 2, which correspond to a fine adjustment of the black and
white reference levels of 20, 15, and 10 mV steps. Monitor the
displayed histograph to choose the appropriate gain level.
•
Interlace—This specifies whether the camera is interlaced or
non-interlaced.
•
Reference Level—This setting optimizes the input signal range and
includes two components:
–
White—The 1408 device uses a programmable white reference
level to optimize the input signal range. Monitor the displayed
histograph to choose the appropriate white offset level. With a
gain of 1, the white reference level is programmable in the
range of 0 to 1.28 V in 64 steps of 20 mV each.
–
Black—The 1408 device uses a programmable black reference
level to optimize the input signal range. Monitor the displayed
histograph to choose the appropriate black offset level. With a
gain of 1, the black reference level is programmable in the
range of 0 to 1.28 V in 64 steps of 20 mV each.
•
Auto Expos.—Pressing this button tells
IMAQconf
to perform a
single acquisition and then calculate the optimum gain and white
and black reference levels.
