The PCI-DIO24H is based on the industry standard 82C55 chip, and the 82C55 I/O pins are brought directly to the boardÃ??Ã?Â¢??s I/O connector. The 82C55 is a powerful 24 bit chip and functions as two 8-bit ports, (Ports A and B) and a third 8-bit port (Port C) that may be further divided into two 4-bit ports (Port C-HI and C-LO). The CMOS outputs of the 82C55 are suitable for driving a wide array of logic devices, though the chips Ã???Ã??Ã?Â±2.5 mA drive capability may not be enough in some applications.
The PCI-DIO24H is connector and software compatible with Measurement Computing's highly popular ISA based CIO-DIO24 board as well as a host of other 8255 based boards from other vendors. The board is also supported by the same wide variety of external relay and solid state I/O module racks as the CIO-DIO24 boards.
The PCI-DIO24H board provides a discrete logic emulation of the 82C55 mode 0, but offers significantly higher output drive capability (64 mA sink, 15 mA source). This mode 0 emulation is fully compatible with the 82C55, and code written for 82C55 mode based boards will function perfectly on the PCI-DIO24H.
The PCI-DIO24H is completely plug-and-play. There are no switches, or jumpers on the board. All board addresses, interrupt channels etc. are set by your computers plug-and-play software.