Sigma LBA-500PC, LBA-710 Pyrocam I with Digital LBA-PC’s, Image synchronization considerations

2.6.1.3.5Camera settings restrictions

Under no circumstances, make any changes to the Advanced. . . Camera settings for the Pyrocam I.

2.6.1.4Image synchronization considerations

The Pyrocam I’s CCIR video output is always producing video images at the rate of 25 frames per second. Furthermore, it only changes output image after acquiring and processing a new image. Thus the rate of a new output beam image is a function of many variables, including Pulse or Chop rates, image processing time, and results computational times.

If you are using a Pulsed laser with your Pyrocam I, the Pyrocam will continue to output the image of the last laser pulse that it receives. As a result, your LBA will continue to collect data frames that are multiples of the last pulse received by the Pyrocam. To relieve this, you may want to set up a Trigger input to the LBA. This will cause, at the most, only one image to be acquired for each Laser Pulse. This can be a tricky situation since the Pyrocam does take a little time to process each image, and that time will vary somewhat from image to image. Also, if your laser is triggered faster than the Pyrocam can acquire and update its CCIR display, it will skip pulses. Thus the LBA can still end up acquiring multiples of some of the processed pulses. You can also try the solution described below for the Chopped-operating mode.

The exact same type of problem occurs in Chopped mode. The chop frequencies must be either 24Hz or 48Hz. Thus, the CCIR image can never be updating as fast as the chopper is triggering the Pyrocam. Consequently, the CCIR output is always creating multiple frames of the same beam profile. In this case, you may want to set the LBA’s Capture interval to a value that will eliminate or reduce multiple frame captures.

2.6.2Pyrocam I with Digital LBA-PC’s

LBA-500/7XXPC-D w/ Digital Camera Option

2.6.2.1Pyrocam I setup requirements:

To use this interface method, your LBA-500/7XXPC must be equipped with the digital camera option (-D), and your Pyrocam I must be of a later design that has digital output capability. Early versions of the Pyrocam were not equipped with digital outputs. If your Pyrocam I does not have a 50 pin connector on its rear cover it can not be interfaced as a digital camera. However, you can still interface it by using the analog method described in the LBA-300PC interface topic. Alternately, you can contact Spiricon’s service department and arrange to have your Pyrocam I upgraded with digital camera output capability.

NOTICE: When interfacing with a Pyrocam I, DO NOT USE THE ULTRACAL! Feature of the LBA-PC. Rather, it is ESSENTIAL that you periodically re-calibrate the Pyrocam I. Calibrating the Pyrocam I is the only calibration that should be used with this type of interface.

Operator’s Manual	29	LBA-PC
Doc. No. 10654-001, Rev 4.10