National Instruments IEEE 1394 用户手册
Chapter 3
Advanced Programming with NI-IMAQ for IEEE 1394 Cameras
© National Instruments Corporation
3-5
Trigger Mode 0
With trigger mode 0, the camera starts frame integration when the external
trigger input changes to an active value. The frame is exposed for a duration
specified by the shutter attribute before the camera transfers the image to
the host computer. No optional parameter is required.
trigger input changes to an active value. The frame is exposed for a duration
specified by the shutter attribute before the camera transfers the image to
the host computer. No optional parameter is required.
Figure 3-3. Timing Diagram for Trigger Mode 0
Trigger Mode 1
With trigger mode 1, the camera starts frame integration when the external
trigger input changes to an active value. The frame is exposed while the
external trigger is active. When the trigger becomes inactive, the camera
stops frame integration and transfers the image to the host computer. No
optional parameter is required.
trigger input changes to an active value. The frame is exposed while the
external trigger is active. When the trigger becomes inactive, the camera
stops frame integration and transfers the image to the host computer. No
optional parameter is required.
Figure 3-4. Timing Diagram for Trigger Mode 1
Trigger
Exposure
Transmission
Frame N
Frame N + 1
Frame N + 2
Start Delay
Start Delay
Start Delay
Start Delay
Start Delay
Start Delay
Frame
N + 1
Frame
N
Frame
N + 2
Trigger
Exposure
Transmission
Frame N
Frame N + 1
Frame N + 2
Start Delay
Start Delay
Start Delay
Start/Stop
Delay
Delay
Start/Stop
Delay
Delay
Start/Stop
Delay
Delay
Frame
N + 1
Frame
N
Frame
N + 2