The sensor converts the reflected laser light into a current signal. The sensor circuit is the main part of the electronics hardware in the detection system. This method improves the time response of the system. The data acquisition software is used to collect, process and display data from the hardware of the detection system. The data are read from the output of sensor electronic circuit periodically.
All tasks have to be done at the same time.
However the data are to be acquired in the same interval from the hardware. In other words the data acquisition task should be deterministic, otherwise information will be lost. The concurrence of the deterministic tasks requires real-time performance of the operating system. The data from the laser detection system are acquired by the PMAC board in a certain interval and written into a buffer in a dual-ported memory by the device driver. The most critical real-time tasks are done primarily by the PMAC board, which is a complete computer system.