CSI Application Note AN-617

Transcription

1 CSI Application Note AN-617 Photron Camera Notes Introduction The newest generation of Photron high-speed cameras are supported directly through Vic-Snap. PC setup To use these cameras, a gigabit (1000mbps) Ethernet adapter will provide the fastest image transfer and control. This may be either onboard the PC or installed as a PCI Express desktop expansion or ExpressCard laptop expansion. The IP address of the host connection should be set to x where x is a number that doesn t conflict with any camera IP s ( usually works well). This can be accessed by using Control Panel Network Connections, right-clicking on the relevant connection, and clicking Properties.

2 Select Internet Protocol (TCP/IP v4), and click Properties. Set the IP address as above, and click OK to complete. Camera setup When using multiple cameras, each camera must be set with a different identifier or IP. For cameras configured by CSI, this will be preset when the cameras are received. For other cameras; if only one camera appears, it's likely that both cameras have the same IP. In this case, it will be necessary to use the PFV software to change the IP of one camera. Connect one camera, start PFV, and select Device Settings from the Help menu. Change the IP from the default to (or 12, 13, etc, for multiple cameras). Hardware connections Connect each camera to AC power using its provided power supply. Connect each camera to the PC (single camera) or to a gigabit Ethernet hub, using a Cat5 or better Ethernet cable. Make the triggering and synchronization connections using BNC cables as described on the following pages.

3 Synchronizing cameras A few hardware connections must be made in total to synchronize two cameras. The connections will depend on whether you are using full-size cameras like the SA series, or Mini series cameras (AX, UX, WX). For full-size cameras Connect the GENERAL OUT1 from the master camera to the SYNC IN of the slave camera(s). By default, the lowest IP-numbered camera will be the master. You can determine this by starting Vic-Snap, and checking which camera shows the SYNC MODE light this camera is the slave. This connection provides a timing signal to keep the cameras in phase for each frame. Connect the selected trigger source to the TRIG SW IN (for make/break triggers such as pickle switches) or TRIG TTL IN (for TTL triggers) of all cameras, using BNC T-connectors as needed. This connection triggers both cameras to start/stop at the same time. For Mini series cameras Connect the OUTPUT 1 (DEF: SYNC OUT) from the master camera to the INPUT 1 (DEF: SYNC IN) of the slave camera. The master and slave can be identified by starting Vic-Snap; the camera which shows the SYNC MODE light is the slave, and the other camera is the master. This connection provides a timing signal to keep the cameras in phase for each frame. Connect the OUTPUT 2 (DEF: TRIG TTL OUT) from the master to the INPUT 2 (DEF: TRIG TTL IN) of the slave. This connection sends the recording trigger signal from the master to the slave so that they begin/end recording at the same time. Connect the trigger signal to a trigger input on the master. If you are using a make/break trigger like the small thumb switch, use the TRIG SW IN connection. If you are using a pulse to trigger, use the INPUT 2 (DEF: TRIG TTL IN). This trigger input will be simultaneously repeated to the slave camera through the TRIG TTL OUT port.

4 Checking the master/slave connection When setup is complete and Vic-Snap is running, the SYNC MODE and SYNC IN lights should be showing on the same camera: If the lights are on different cameras, or if a camera shows "Sync Mode" but not "Sync In", please check connections. Acquiring calibration images To acquire calibration images, select the Random trigger and start recording. Then, click the trigger switch once for each calibration image. When complete, proceed according to Saving Images below. Acquiring test images To acquire test images, confirm that the cameras are synchronized. Then, use the relevant trigger mode (Start, Center, End, or Manual). For some tests, you will need to reduce resolution to achieve the frame rate necessary. DIC can be performed (with reduced spatial resolution and strain accuracy) at resolutions as low as 128x128.

5 Data acquisition To acquire high-speed data, use a DAQ which supports digital timing and triggering. Connect the master camera s Trig TTL Out connector to the PFI0 input on the DAQ. Connect the master camera s General Out 1 connector to the PFI1 input on the DAQ. Connect the analog signal(s) to the AI line(s). Data will be acquired automatically in start, manual, center, and end trigger modes. Note that when using trigger modes other than Start, you must let the acquisition buffer fill before finishing the acquisition. For example, if your camera stores 5000 frames and you are in End trigger mode at 500fps, you must let at least 10 seconds go by after entering record mode and before triggering. Maximum sample rates will vary by device. The maximum rate is listed in the Advanced Options dialog under Data Acquisition; for most devices, this rate can be increased by reducing the number of channels sampled. Saving images When acquisition is complete, Vic-Snap will switch to the Playback mode. You may play through the video, mark the start and end frame, and save selected frames. Analog data, if present, will be written the the.csv file associated with the project.

6 Other considerations By default, the shutter speed will be set to the inverse of the frame rate i.e., for a frame rate of 1000fps, the shutter speed will be set to 1/1000=1ms. Where significant motion happens from one frame to the next, this shutter speed setting will result in motion blur. For a typical test, the shutter speed will be a small fraction of the frame rate. For critical tests that use strobe lighting, it may be helpful to perform a dry run to check lighting levels through the duration of the test. The selected lighting should result in neither overdrive at the peaks nor overly dim images away from the peak. Sometimes, a test must be run at reduced resolution (i.e., 256x64) to achieve the necessary frame rate. In this case, it is not necessary to calibrate at the reduced resolution. Acquire images at the full resolution, and calibrate in Vic-3D. Then, add the reduced-resolution speckle images. Click Calibration Adjust for cropping in Vic-3D, and (for Photron cameras) accept the default values. This adjustment must be performed only once. Troubleshooting Support No cameras appear in the software: check that the cameras are connected and that the cameras and hub are powered. Confirm that the IP of the computer is set correctly. Be sure the firewall is off or that Vic-Snap is allowed through. Only one camera (of two) appears: check that the two cameras are set with unique IP addresses. Torn images, no images, image corruption: confirm that the cameras are synchronized - all cameras except one should show both "Sync Mode" and "Sync In". The master camera should show neither. If you have any questions about this Application Note or any other questions, comments, or concerns about our systems, please feel free to contact us at support@correlatedsolutions.com, or visit our web site at