GigE FC11000GE Instruction Manual page 7

● LED Vinit signal monitor indicator
When this camera is set in the asynchronous shutter mode, the LED indicator on the rear
panel of the camera lights up in red for one shot in response to the input of the external
trigger signal (Vinit signal).
This allows the user to confirm the state of signal input.
The red LED lights up for a certain period of time (for about 100 ms) each time for a
trailing edge of the trigger input. If a following trigger signal is input within this period, the
lighting time of the LED will be retriggered and extended.
Since the lighting of the LED responses only to the trailing edge of the
trigger input, it lights up only once for 100 ms even if the trigger input
pulse duration is longer than the one shot time of period.
● Setting of various asynchronous shutter modes
Set the parameters and others in accordance with the following table:
Asynchronous shutter mode
Preset shutter (PWC=DISABLED)
Preset shutter (PWC=ENABLED)
Pulse width control
(Note) When shutter switch is 0, "Continuous image output(without shutter)" is applied for the all.
(Note) For setting methods for the respective parameters of "PWC" and others → See " How to set operation mode".
● Recommended timing of asynchronous shutter trigger signal (Vinit signal) for preset shutter/pulse width control
For the case of preset shutter mode, the negative logic pulse is
applied within the width range from 1 H (1 horizontal
synchronous interval) to 40H as described below.
For this case, the exposure operation starts in synchronization
with the trailing edge of the applied pulse.
For the case of the pulse width control exposure mode,
numeric value of the L level interval of the input Vinit pulse
(shown as Tvinit in the figure) is retrieved in synchronization with
the trailing edge of the internal HD pulse, and the integer
multiple number of H (1 horizontal synchronous interval) that is
closest to the retrieved Vinit pulse duration is transmitted as nH
to the inside of the camera. Then the shutter speed is
determined in response to the time nH.
(Note) In the pulse width control, the shutter exposure time is almost equal to the integral multiple number of the
horizontal synchronous time (H) that is closest to the Vinit pulse duration. More specifically, however, the
shutter exposure time is indefinite for the time period corresponding to 1H width in the case of normal external
trigger input (or the case where the Vinit signal is not in synchronization with the horizontal synchronous
timing of the camera).
→ Refer to the timing chart described in another section for the details.
(Note) When the shutter exposure time is too long in the pulse width control mode, the S/N ratio of the image will
be degraded due to the reduction of dynamic range of CCD, accumulation of thermal noise components of
CCD image sensor in proportion to the shutter speed and other factors. Therefore, if a long exposure time is
employed, it is recommended to conduct experiments using realistic exposure times in actual conditions to
check for the appropriateness.
● Example of drive circuit for Vinit input circuit
[E xam ple of user c ir cui t]
VCC
74AC04 or 7 5
other s
VCC i s +5V or +3.3V
* The Vinit signal should not include unnecessary noise components such as chattering.
[Input voltage range]
H level 2.5 to 5.5 V
L level -0.5 to 0.5 V
* he voltage of the terminal end on camera side is required to be within the above voltage range with the camera being connected.
T
Table 4-1 Setting of various asynchronous shutter modes
PWC Shutter switch
DISABLED
ENABLED
Vini t1 IN
Camera
6
connector
Remark
1 to 9
1 to 8
9 Shutter switch = 1 to 8: same as preset shutter
Vinit
[For the case of preset shutter mode]
1H ≤ Tvinit ≤ 40H
(The exposure time is independent of the Vinit width.)
1H=1 horizontal scan time
[For the case of pulse width control mode]
(Where PWC=ENABLED, shutter switch = 9)
nH ≤ Tvinit <(n+1)H (n is 1 or larger integer.)
(This is the pulse width where shutter exposure time =nH)
Ins ide of cam era
3 .3 V
3. 3V
4. 7k
4 7p
10 k
10 0
3. 9 ZD
G igE Serial I/F
Fig. 4-4. Vint circuit
- 7 -
K09821;7/37
U
D
E XP . M O DE
Red LED lights up in red in response
to trigger signal input (Vinit).
Fig. 4-2. LED indicator
Tvinit
Fig.4-3 Vinit signal timing
T C7 4LVX14 o r e qui vale nt
To internal circ ui t
Op era tio n in dic ato rLE D
L E NS
P OW E R