JAI CM-140GE User Manual

Also see for CB-140GE: User manual

JAI CM-140GE User Manual Manual pdf 24 page image

CM-140 GE / CB-140 GE8.3.3 Electronic ShutterCM-140GE / CB-140GE have conventional shutter functions as well as the GenICam standard “ExposureTime Abs” function.Preset Shutter10 steps preset shutter are available: OFF (1/31); 1/60, 1/100; 1/250; 1/500; 1/1,000; 1/2,000;1/4,000; 1/8,000; 1/10,000 sec. (See the register map included in the SDK documentation for detailshow to configure this register - 0xA004)Programmable ShutterIt is possible to set the shutter speed in the range of 2L to 1052L by 1L unit, in case of Full Frameoperation. When 625L is set, it is the equivalent of “OFF (1/31)“ or 32.17ms. (See the register mapincluded in the SDK documentation for details how to configure this register - 0xA008)Pulse Width ControlWith this mode selected the exposure time is controlled by the width of the trigger pulse. Theminimum trigger pulse width is equal to 1L (30.584μs)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 address0xA018. The entered absolute time (Time Abs) is then converted to programmable exposure (PE) valueinside the camera.The below equations show the relationship between the PE value used by the camera for the differentreadout 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 alwaysoccur.The relation between PE value and Time Abs:Normal readout PE= 2 + INT ( Exposure time -61) μs / (1988 [pixel clocks/line]/65000000[pixel clk])V Binning readout PE= 2 + INT ( Exposure time -77) μs / (2524/65000000)INT means integer (rounded down).The below table shows minimum and maximum values for each readout mode.Minimum value Maximum ValueNormal Scan 61μs 32,175 ms2/3 Partial Scan 61μs 25,019 ms1/2 Partial Scan 61μs 21,471 ms1/4 Partial Scan 61μs 16,149 ms1/8 Partial Scan 61μs 13,519 msV-Binning Scan 77μs 20,464 msGPIO in combination with Pulse Width triggerMore precise exposure time can be obtained by using the GPIO in combination with Pulse Width triggermode. The clock generator and counter can be programmed in very fine increments.Minimum Shutter Time 2L Maximum Shutter Time30.584μs(1L) * 2 = 61.168μsNormal 30.584μs * 1052L≈ 1 Frame(32.17ms)38.83μs * 2L = 77.66μs 38.83μs * 527L ≈ 20.46msV Binning- 24 -