30
Camera Operation & Features
Document No.: 04646-01
PixeLINK PL-A780
MACHINE VISION CAMERA
SYSTEM GUIDE
Copyright © 2004 PixeLINK
All Rights Reserved
Table 10 Feature Control Register Min/Max Values.
Feature Control Register
Values
Corresponding Absolute
Values
Feature
Min Max Min Max
Frame Rate
1
4000
2.0
8000.0
Gain 0
2210
0.0
22.1
Gamma 1
40
0.1
4.0
Saturation 0
250
0.0
250.0
Shutter 1
4095
0.0001
0.4095
Trigger Delay
0
2500
0.0
2.5
White Balance
320
500
3200
5000
White Shading
0
255
0.0
4.0
5.1.3.1 Frame Rate
The frame interval and the required bandwidth on the FireWire
bus are fixed by the Frame Rate value. The available frame rate
range depends on the current video format and/or video mode.
Programmers are recommended to check the ON/OFF setting
and minimum and maximum value after video format, ROI and/or
video mode have been changed.
When the Frame Rate feature is ON, the exposure time (Shutter)
is limited by the frame rate value dynamically. When the Frame
Rate value is changed, the minimum and maximum limits on the Shutter control will change
accordingly. The Shutter value will be forced to lie within these limits.
After a change to ROI, video format or video mode, the Frame Rate control will attempt to
maintain the same frame rate. If this is not possible, the Frame Rate control will be turned
OFF.
When the Frame Rate control is OFF, the frame rate value defaults to the maximum
isochronous frame rate. The frame rate is then a function of the exposure time for exposures
longer than the inverse of the frame rate value. For shorter exposure times, the frame rate will
be constant.
The absolute maximum frame rate is achieved by using asynchronous communication on the
FireWire bus. To set the maximum output frame rate, ensure the Frame Rate control is ON
and set the control to its maximum value.
The minimum frame rate (maximum frame interval) in rolling shutter mode (See Section 3.2.3
on page 12) is determined by the ROI height (number of pixel rows). The equation below
determines the maximum frame interval, in milliseconds, for a given ROI height.
Height
ROI
terval
MaxFrameIn
∗
=
8192
.
0
In Fast Reset Shutter mode (see Section 3.2.3 on page 12), the Frame Rate control can be
used to control the bandwidth on the FireWire bus. The frame interval can be effectively
controlled by the trigger or by adding delays to the internal trigger. The maximum internal
delay is 2.5 seconds.
Auto No
Manual Yes
One-time
Auto
No
Off Yes
CiD No
