JAI AM-1600GE, Руководство пользователя, Страница: 34 / 71

AM-1600GE / AB-1600GE
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8.3.4
Electronic Shutter
The AM-1600GE/AB-1600GE allows the shutter speed to be selected in three ways ;
Programmable Shutter (up to 3327 line periods, 1 LVAL increments), Auto Shutter and
Exposure Time Abs which is the GenICam standard.
‹ Programmable Shutter
The exposure time can be programmed in 98.6 μ s (LVAL period) increments. The range is from
3 LVAL to 3327 LVAL. OFF is 3327 LVAL. (See the register map included in the SDK
documentation for details how to configure this register - 0xA008)
where, L is LVAL.
‹
Exposure Auto Continuous (Auto Shutter)
In this mode, the shutter continuously functions in order to get proper video output level in
accordance with incoming light. The range of control is OFF(1/3 second) to 1/101.35 second.
‹
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 (
μ s) in
register address 0xA018. The entered absolute time (Time Abs) is then converted to
programmable exposure (PE) value inside the camera.
The formula below shows the relationship between the PE value used by the camera for the
different readout modes and the value entered in register 0xA018.
Due to rounding down, some errors may occur.
The relation between PE value and Time Abs
Normal readout PE= 3 + INT (Exposure time -296) µs / (2960/30000000)
V Binning readout PE= 3 + INT (Exposure time -320) µs / (3200/30000000)
Note: INT means round down
The following table shows minimum value and maximum value for each readout mode.
Minimum value Maximum Value
Normal Scan 296 μ s 328264 μ s
1/2 Partial Scan 296 μ s 181448 μ s
1/4 Partial Scan 296 μ s 108040 μ s
V-Binning Scan 320 μ s 177600 μ s
‹
GPIO in combination with Pulse Width Control trigger
More precise exposure time can be obtained by using GPIO in combination with Pulse Width
mode. The clock generator and counter can be programmed in very fine increments.
For an example, refer to chapter 6.5.1.
Minimum Shutter Time 3L Maximum Shutter Time
Normal 98.6µs(1L) * 3L = 295.8 µs 98.6 µs * 3327L ≈ 328 ms
V Binning
106.6 µs * 3 L = 319.8 µs 106.6 µs * 1665 L ≈ 177.5 ms