Development of Real Time Linux Device Driver for PCI based Data Acquisition System

This paper elaborates development and implementation of hard real time device driver for PCI based data acquisition of analogical and digital data. Device driver was developed using the RTDM (Real –Time Driver Model) skin over Xenomai kernel. The system consists of two PCI based cards. First card consisted of 12-bit ADC, 12-bit DAC, Programmable Digital I/O lines (TTL compatible) and Timers/Counters. Second card consisted of Programmable Digital I/O lines and Timers/Counters only. In order to test all the features and performance, a test system consist of temperature sensors and output of DAC was connected to channels of ADC. Switches are connected to second card in order to generate conditioned input for the programmable digital I/O lines of the DIOT (Digital Input/output Timer card) card. Finally, both drivers were tested with this arrangement and with multiple application accessing drivers at same time, and the interrupt latencies were noted to be around 5μsec.