For long exposure times

When exposure times longer than the currently set frame rate cycle are set, the camera enters the long exposure time mode, and the actual frame rate is slowed in accordance with the exposure time.

Absolute Control Value for the Shutter

Control of exposure time using absolute values is possible. The values are indicated using a 32-bit floating point value. (Unit: sec.)

The control steps are synchronized with the pixel clock, and as the pixel clock is 30.5 MHz, one step is approximately 32.8 ns.

The range for these values extends from 10 microseconds to 17.5 seconds.

Programming example;

union {

 

 

DWORD

dwValue;

// 1394 is expressed in quadlets,

float

fValue;

// exposure time is indicated in seconds.

} AbsoluteShutterValue;

AbsoluteShutterValue.fValue = Exposure time;

WriteQuad(AbsoluteShutterOffsetAddress,

AbsoluteShutterValue.dwValue);

WriteQuad is a virtual function used to write in the register.

AbsoluteShutterOffsetAddress is an offset address for the absolute value control. See page 25 for the formula for the offset address.

Auto Exposure

AutoExposure is a function that automatically adjusts the gain and shutter settings, based on the brightness of the subject. When this function is used, make sure the video mode is set to one of the following modes. This function is not effective in any other modes.

XCD-SX910CR/SX910UV/SX910

Format2Mode2 (1280 ⋅ 960)

15 fps

TriggerOFF

XCD-X710CR/X710

Format1Mode5 (1024 ⋅ 768)

30 fps

TriggerOFF

Functions

Trigger Shutter

Trigger shutter is useful for capturing images in response to a trigger that starts the exposure to match a preset timing. It can also be used to capture an image using multiple cameras with the same timing. When a trigger shutter is used, the required trigger is input via the BNC connector on the rear panel. The input signal is a 5-volt negative pulse. The falling edge of the signal is detected as the trigger, and the unit is equipped with an exposure time consisting of the shutter parameter set as trigger mode 0, and trigger mode 1 that controls the exposure timing using the width of the trigger signal pulse. When trigger mode 0 is used, the minimum width of the trigger is 10 microseconds. When trigger mode 1 is used, there is no limit to the exposure time.

This unit can also be used with a software trigger that issues the trigger signal via a software command. Both trigger mode 0 and trigger mode 1 can be used with software triggers.

Trigger shutter

4.0 – 5.0 Vp-p

10 ∝sec or more

• Input impedance: 10 kΩ

XCD-SX910CR/X710CR

 

XCD-SX910UV

9

XCD-SX910/X710