Opis

The 104-DIO-48S and 104-DIO-24S provide a total of 48 or 24 lines of digital I/O with counter/timer for PC/104-based data acquisition. This low-cost, high-performance, reliable board features Change of State (COS) detection on user-selected ports, allowing the board to generate an interrupt port by port. Since one READ determines the data, there is no need for constant polling, which greatly reduces processor overhead and allows applications to run more smoothly.

The 104-DIO-48S board uses two 82C55A chips to provide a computer interface to the 48 I/O lines. Each chip provides two 8-bit ports and two 4-bit ports with software programmable direction. Each I/O line is buffered and capable of sourcing 32mA or sinking 64mA. Pull-ups to 5V are provided for contact monitoring. Optionally available is an 82C54 chip that includes three 16-bit counter/timers factory configured in an optimal module for use as event counters, frequency output, pulse width, and frequency measurement. Connections are made via two industry-standard 50-pin headers plus one ten-pin header for the optional counter/timer.

• 48 or 24 parallel lines of 82C55 digital I/O with tristate buffers prevent unintended control of external equipment
• IRQ on input change of state (COS) eliminates the need for constant polling
• High sink/source current 64mA/32mA
• I/O pulled up to 5V for contact monitoring
• Compatible with Opto-22 and other industry standard I/O racks