JAI CV-M50 Operation Manual

Contents

JAI CV-M50 Operation Manual Manual pdf 13 page image

- 12 -CV-M506.3.4. Long Time Exposure ModeThe Long time exposure will work in 3 modes:1. Interlaced with field accumulation.2. Interlaced with frame accumulation.3. Non-interlaced with field accumulation.The exposure time is the interval between 2 ext. VD pulses sent to the camera VD input. Each ext. VDpulse will reset and restart the internal VD in the camera as for ext. HD/VD input. So the camera issynchronized to the external HD/VD supply after each VD input.An exposure starts after input of an external VD pulse, and ends after the next input of ext. VD, whichagain starts a new exposure.The long time exposure is a continuous process where each external VD will synchronize the camera,stop an exposure, start a new exposure and read out the previous accumulated signal as interlaced ornon-interlaced fields.The exposure control can be done by feeding every Nth VD pulse from the external HD/VD supply to thecamera. N is the wanted exposure time in number of fields. This is typically done in the frame grabberPC.The range for long time exposure is from 1 V (a single field) to ∞. However the dark current signal willincrease by longer time, so >2 seconds are not recommended at normal ambient temperature.To use this mode:Set: SW1-1, 2 and 3 to OFFSW1-4 to OFF for normal shutter.SW1-5 to ON for frame accumulation or OFF for field accumulation.SW1-6 to OFF for 2:1 interlaced or ON for non-interlaced.Jumper JP6 on PK8057 to CLOSEInput: Ext. VD pulses with the exposure interval to pin 7 on 12 pin multi connector.Ext. HD to pin 6 on 12 pin multi connector.75 Ohm termination is done with SW2-1 and SW2-2 on PK8057 board.The timing for the external VD interval has to be as follow. (V is the time for a single field)Interlaced with field accumulation. 1 V or moreInterlaced with frame accumulation. 2 V or integral number of 2VNon-interlaced with field accumulation. 2 V or moreNote: The external HD/VD sync. generator, which supply the ext. VD an HD signals should follow thescanning standard for the camera setting.EIA CCIRInterlaced and field accumulation. 1 V = 262.5 H 1 V = 312.5 HInterlaced and frame accumulation. 2 V = 525.0 H 2 V = 625.0 HNon-interlaced and field accumulation. 2 V = 524.0 H 2 V = 624.0 HRefer to Timing Chart and Cautions on next page.Detailed switch and jumper setting is described in “7. Mode Setting”.For connections see 5. “Pin Assignment”.