ShimadzuHpvxCamera

This is the Karabo device class to control a Shimadzu HPV-X2 camera through an RCS IPC [*].

The main feature of this camera is the capability of acquiring a sequence of 128 (or 256) frames up to a MHz acquisition rate. The burst of images is recorded locally on the camera, then played back at a later stage.

Please read rcsCameras Package documentation for general information about the hardware configuration.

Please refer to the user manual for further reference.

[*]For this camera the IPC is running a windows OS.

Known Issues and Workarounds

1. The functioning of the camera implies that the multi-frame images are delivered on the karabo device output channels with a huge (> ~10s) delay. This is way beyond the usual maximum accepted delay of the DAQ Data Aggregator. For this purpose a dedicated data aggregator has been prepared and must be used. The data aggregator has been set with 15 s maximum delay. Such a delay can be easily exceeded by configuring the multi-frame acquisition.

The parameters that affect this delay are (summing up their effect): * The recordingSpeed parameter (which is the inverse of the frame rate whithin the

bursts).
  • The number of frames in the burst (128 or 256).
  • The duration of the burst recording, which equals to recordingSpeed x 128 (256).
  • The streamingRate parameter (which is the rate at which the recorded burst is played back). Empirically, the value of 33 Hz for this has been proven the maximum working without losses. This means an overhead of ~ 4 s for 128 frames bursts and ~ 8 for 246 frames ones.
  • There is a fixed overhead on top of that (whose major component has to do with the acquisition hardware) of the order of few seconds.

The train ID of the image burst is assigned as the one of the first frame, based on the operating system time of the Windows IPC. That’s why the delay may also be affected by a poor NTP synchronization of the Windows IPC.

For reason that are not yet understood, it has been observed that the delay may increase over time with respect to the one observed after a fresh reboot of the Windows machine.