The PCI-DIO-24S and PCI-DIO-48S PCI digital I/O cards are distinctive in their ability to monitor the state of all inputs. If one or more of the bits change state, a latched interrupt request can be generated. As a result, it is not necessary to use software to continuously poll the inputs to detect a change-of-state condition. The change-of-state interrupt is enabled by a software write command to the interrupt enable register. Once latched, the change-of-state interrupt can be cleared by a software write. The PC-DIO-24S has 24 lines, whereas the PC-DIO-48S has 48 lines.

This change-of-state feature is especially useful in applications involving automatic test systems, laboratory automation, robotics & machine control, security systems and energy management to name a few. Operating system support includes DOS and Windows 95/98/NT/2000/XP.

The cards are programmable to either accept inputs or provide latched outputs on two groups of three, eight-bit ports. Each I/O line is buffered and capable of sourcing 15mA or sinking 24mA of current. Tristate I/O line buffers are configured automatically by hardware logic for input or output in accordance with the programmable peripheral interface chip control register. Pull-up resistors ensure there are no erroneous outputs at power up until the software has initialised the card.

I/O wiring connections are through a 50-pin header on the card. Flat ribbon cables can be connected to the STA-112 termination board or STB-50 50 way breakout screw termination panel. The PCI-DIO-24S and PCI-DIO-48S cards use one address space, occupying sixteen consecutive register locations. The systems Plug and Play BIOS determines the resources assigned to the cards which can be located anywhere in the 0000 to FFFF hex address range.

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