Programmable Exposure-Continuous Mode; Asynchronous No Shutter Mode; Asynchronous Programmable Exposure Mode; Figure 21. External Trigger Timing - JAI RM-4200CL User Manual

RM/TM-4200CL Series
3.3.2

Programmable Exposure-Continuous Mode

The exposure time of RM-4200CL can be specified from one video line to a maximum of one frame using the
serial communication commands in the Continuous Mode. There is overhead where the specified exposure time
is n video lines, making the real exposure time equal to
In this mode the maximum exposure time is equal to the setting for one frame. If the user specified exposure
time is longer than the time allowed for one frame, it will be ignored by the camera.
3.3.3

Asynchronous No Shutter Mode

In Asynchronous No Shutter Mode, applying the external trigger starts a camera scan reset. The camera finishes
the line it is scanning and scans an additional 9 video lines, this charge is sent to the horizontal register.
Because the external trigger is randomly applied, the new image charge may overlap with the previous image.
To prevent an existing charge accumulation from interfering with a new image, most users set up the
application in a dark area and depend on a strobe light for illumination. From the time the external trigger
activates until the transfer gate turns off, about 9.5 video lines are available for integration; if everything is
properly configured, the strobe flashes during this time.
Figure 21. External Trigger Timing.
3.3.4

Asynchronous Programmable Exposure Mode

In Asynchronous Programmable Exposure Mode, when an external trigger is applied, the exposure starts after
one discharge signal (Vsub), which happens after the trigger's active edge is off. Because the discharge signal
(Vsub) synchronizes with LDV in this mode, there is a maximum one video line of jitter between the trigger
active edges to discharge signals (Vsub) off. In this mode, the exposure time from 1 video line to 2080 video
lines can be controlled through serial communication commands in one video line steps. In this mode, the
minimum exposure time is equal to 1 video line plus overhead: the maximum exposure time is equal to 2080
video lines plus overhead. Where the specified exposure time is n video lines, the real exposure time is equal
to:
Functions and Operations 17