JAI CV-A1-20 - Manual (Page 11)

CV-A1-20
6.4. External Trigger Modes
This camera has 6 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. (HC=0, HC=1)
3. Frame Delay read out mode. TR=3 PWC exposure read out by ext. VD. (HC=0, HC=1)
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
6. Smearless Read out mode. TR=6 Pre-sel. exp. after dummy readout. (SM=0, SM=1)
The default accumulation is HD synchronously accumulation (HC=0). The accumulation starts at
the first HD after the trigger leading edge. Fig. 18. To avoid the <1H jitter caused by this delay,
synchronize the external trigger to HD as shown in fig. 17 below. The trigger level translations
should be placed inside the 8 + 4 µseconds.
In PWC mode (TR =2) and Frame Delay readout (TR=3), the accumulation mode HC can be set to
asynchronous accumulation (HC=1). The exposure will start immediately at the leading edge of
the trigger pulse without waiting for the HD. Fig. 19. below.
In Edge pre-select TR=1 and smearless TR=6, the shutter mode can be SM=0 or SM=1.
Ext. HD
TRIG
8 µ s 4 µ s 8 µ s 4 µ s
>1H
Ext. HD
TRIG
8 µ s 4 µ s 8 µ s 4 µ s
>1H
Fig. 17. Trigger/HD Timing.
t
1
t
2
t
3
t
4
t
5
HD
Trigger
Xsub
Xsg
EEN
Accum
t
1
t
2
t
3
t
4
t
5
HD
Trigger
Xsub
Xsg
EEN
Accum
HD
Trigger
Xsub
Xsg
EEN
Accum
Fig.18. Pulse Width H Synchronous Accumulation
H D
T rigger
X su b
X sg
E E N
A ccum
t
1
t
2
t
3
t
4
H D
T rigger
X su b
X sg
E E N
A ccum
t
1
t
2
t
3
t
4
Fig. 19. Pulse Width H Asynchronous Accumulation.
Note: Xsg and Xsub are internal signals in the camera. They are shown in the timing diagram for better understanding.
- 10 -