Test and Measurement Forum

Hi.
I need something like PicoLog 1216 but I have dilemma/question.

Namely, in my experiment I collect data from acquisition card every one second (it is X-ray experiment and data are one-dimensional array containing photon counts on different detector channel). Now I need something to monitor intensity variation from X-ray tube. With the combination of photo-diode (placed in the direct X-ray beam) and PicoLog 1216 I can monitor voltage variation from photo-diode and relate this to the intensity variation from X-ray tube.
I want to collect from 'PicoLog-photo-diode' voltage values also every one second.
On the other hand, what I need is as much as possible those values in one reading in order to obtain good statistics of intensity variation in this one second. In other words, during that one second 1216 should sample as much as it can voltage values and after this one second I should be able to drag voltage values from its memory (1216 has internal 8k-memory, right?) to PC memory. After that, 1216 clears its memory and starts to sample (and store in its memory) another set of voltage values for one second, and so one.
Can I do this with 1216? If yes, which functions (and arguments) are defined for that?

Thank you for the answer

Kreso

Dear Kreso,

Thankyou for your inquiry with regard to your 1216 application.

Capture modes
Three modes are available for capturing data:
BM_SINGLE: collect a single block of data and exit
BM_WINDOW: collect a series of overlapping blocks of data
BM_STREAM: collect a continuous stream of data
BM_SINGLE is useful when you wish to collect data at high speed for a short period: for example, to collect 1000 readings in 50 milliseconds.

BM_WINDOW is useful when collecting several blocks of data at low speeds - for example when collecting 10,000 samples over 10 seconds. Collecting a sequence of single blocks like this would take 10 seconds for each block, so displayed data would
not be updated frequently. Using windowing, it is possible to ask for a new block more frequently, for example every second, and to receive a block containing 9 seconds of repeat data and 1 second of new data. The block is effectively a 10-second window that advances one second per cycle.

BM_STREAM is useful when you need to collect data continuously for long periods. In principle, it could be used to collect data indefinitely. Every time pl1000GetValues is called, it returns the new readings since the last time it was called. The noOfValues argument passed to pl1000Run must be sufficient to ensure that the buffer does not overflow between successive calls to pl1000GetValues . For example, if you call pl1000GetValues every second and you are collecting 500 samples per second, then noOfValues must be at least 500, or preferably 1000, to allow for delays in the operating system.

In addition to this The function pl1000SetInterval allows the user to specify the block duration and the number of samples that they wish to collect.

if you require further assistance please do ont hesitate to contact me on support@picotech.com

Kindest regards,

Stuart
Technical Specialist