JAI CV-A50, CV-A60 operation manual External Trigger Modes, Start/stop Mode. TR=5

CV-A50 / CV-A60

6.4. External Trigger Modes

This camera has 5 external asynchronous trigger modes, which can be set by RS-232C commands.

1.	Edge Pre-select Mode.TR=1	Pre-selected exposure. (SM=0, SM=1)
2.	Pulse Width Control Mode. TR=2	Pulse width controlled exposure.
3.	Frame Delay read out mode. TR=3	PWC exposure read out by ext. VD.

4.Long Time Exposure Mode. TR=4 Exposure is interval between ext. VD.

5. Start/stop Mode. TR=5 Exposure start by trigger and stop by ext. VD

An external trigger pulse initiates the capture (input on pin 11 of the 12-pin Hirose connector or pin 5 of the 6-pin Hirose). The leading edge of the trigger pulse initiates the exposure (this is a falling edge if factory default) and the duration of the pulse governs the exposure (accumulation) time. If the polarity of this pulse is reversed, the camera can be configured to correct for it.

The duration of the external trigger pulse must be greater than 1H. It is recommended to make this longer, typically 9H.

Important notes on using trigger modes:-

The accumulation is HD synchronously accumulation. The accumulation starts at the first HD after the trigger leading edge. Shown in fig. 15. To avoid the <1H jitter caused by this delay, synchronize the external trigger to HD as shown in fig. 14. The trigger level translations should be placed inside the time A, which is 8 µseconds.

Do not input a new trigger before the previous video is read out. (WEN is high).

A==88µsecµ ec

HD

Trigger

Accum

Xsub

Xsg

EEN

Fig. 14. Trigger/HD timing.

t1 t2 t3 t4 t5

Note: Xsg and Xsub are internal signals in the camera. They are shown in the timing diagram for better understanding.

Fig. 15. Pulse Width H synchronous accumulation.

Fig. 16. Ext. HD and ext. VD phase conditions.

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