Electronic Shutter - JAI CM-030 GE User Manual

8.3.3 Electronic Shutter

CM-030GE / CB-030GE have conventional shutter functions as well as the GenICam standard
"Exposure Time Abs" function.
Preset Shutter
10 steps preset shutter are available: OFF (1/90); 1/100, 1/120; 1/250; 1/500; 1/1,000;
1/2,000; 1/4,000; 1/8,000; 1/10,000 sec.
(See the register map on Section 10 for details how to configure this register - 0xA004)
Programmable Shutter
It is possible to set the shutter speed in the range of 2L to 511L by 1L unit, in case of Full
Frame operation. When 511L is set, it is the equivalent of "OFF (1/90)" or 11.037ms.
(See the register map Section 10 for details how to configure this register - 0xA008)
Normal
V Binning
Pulse Width Control
With this mode selected the exposure time is controlled by the width of the trigger pulse. The
minimum trigger pulse width is equal to 1L (21.6 µs)
Exposure Time Abs (GenICam Standard)
This is a function specified in the GenICam standard.
The shutter speed can be entered as an absolute exposure time in microseconds (μs) in
register address 0xA018. The entered absolute time (Time Abs) is then converted to
programmable exposure (PE) value inside the camera.
The below equations show the relationship between the PE value used by the camera for the
different readout modes and the "Exposure Time Abs" value entered in register 0xA018.
As the calculation is based on rounding down to the closest integer, precise values may not
always occur.
The relation between PE value and Time Abs:
Normal readout
V Binning readout
(1) INT means integer (rounded down). (2) Pixel clocks/line. (3) Pixel clock
The following table shows minimum value and maximum value for each readout mode.
Normal Scan
2/3 Partial Scan
1/2 Partial Scan
1/4 Partial Scan
1/8 Partial Scan
V-Binning Scan
CM-030 GE / CB-030 GE
Minimum Shutter Time 2L
21.6 µs(1L) * 2L = 43.2 µs
23.4 µs * 2L = 46.8 µs
(1)
PE= 2 + INT (Exposure time -43) µs / (864 /40000000 )
PE= 2 + INT (Exposure time -46) µs / (936/40000000)
Minimum value
43us
43us
43us
43us
43us
46us
Maximum Shutter Time
21.6 µs * 511L≈ 1
23.4 µs * 257L ≈ 6.0138 ms
(2)
Maximum Value
11.037ms
7.733ms
6.221ms
3.867ms
2.722ms
6.013ms
- 23 -
(3)
511L
358L
288L
179L
126L
257L