CV-A50 IR
6. Functions and Operations
Apart from the standard continuous operation, the CV-A50 IR features three external
asynchronous trigger modes (edge pre-select, pulse width controlled and start/stop) and a
special frame-delay readout mode. Long integration time mode is also supported.
6.1. Basic functions
Some of the primary camera functions need a general introduction before the operation modes
are described. The list below shows the primary functions from the command list.
SM Shutter Mode
Normal shutter, Programmable Exposure
SH Shutter Speed
Off to 1/10,000 second
PE
Programmable Exposure 1.5 H to 1023.5 H
SC
Scanning Format
Interlaced, non-interlaced, (1/2 partial, 1/3 partial)
TR Trigger Mode
Normal, Edge, PWC, frame delay readout
Long time exposure, start-stop
FR
Accumulation
Field,
Frame
The shutter
SM
can be set to normal (SM=0), where the exposure time is selected from 8 fixed
step with the command
SH
, or programmable exposure (SM=1). Here the command
PE
allows up
to 1023 steps with 1 period resolution (64
μ
s) for edge pre-select mode. For normal modes PE
can be up to 312 for CCIR and 262 for EIA.
The scanning format
SC
can be selected between interlaced and non-interlaced sync signals.
Further it is possible to select 1/2 and 1/3 partial scanning. It is not supported for the camera.
The accumulation
FR
can be field or frame. Fig. 9. shows details for frame and field
accumulation with shutter OFF, (left(, and shutter on, (right).
The accumulation in all trigger modes is H synchronous. The exposure will start at the first HD
pulse after the trigger falling edge. Fig. 8. shows the details. In all triggered shutter modes, the
shortest shutter time is limited to
≥
1.5 H or 1/10,000. In trigger modes, the exposure time is not
limited to the readout time. It can be longer.
HD
Trigger
Accum
Fig. 8. PWC H synchronous accumulation.
b
E
E
Time
Frame accum.
Field accum.
Photo
charge
Photo
charge
Video out
E
O
Video out
E
O
Field 1
Field 2
Field 1
Field 2
t0
t1
t2
t3
t4
VD
Xsg1
Xsg2
Xsg
Interlaced
Sync
Interlaced
E
E
Time
Frame accum.
Field accum.
Photo
charge
Photo
charge
Video out
E
O
Video out
E
O
Field 1
Field 2
Field 1
Field 2
t0
t1
t2
t3
t4
VD
Xsg1
Xsg2
Xsg
Interlaced
Sync
Interlaced
Non-interlaced
E
E
Time
Frame accum.
Field accum.
Photo
charge
Photo
charge
Video out
E
O
Video out
E
O
Field 1
Field 2
Field 1
Field 2
t0
t1
t2
t3
t4
VD
Xsg1
Xsg2
Xsg
Interlaced
Sync
Interlaced
Non-interlaced
E
E
Time
Frame accum.
Field accum.
Photo
charge
Photo
charge
Video out
E
O
Video out
E
O
Field 1
Field 2
Field 1
Field 2
t0
t1
t2
t3
t4
VD
Xsg1
Xsg2
Xsg
Interlaced
Sync
Interlaced
Fig. 9. Frame and field accumulation without shutter (left) and with shutter (right).
- 6 -
