Manual USB-DIO-48
6
Functional Description
This USB board is an ideal solution for adding portable, easy-to-install digital I/O capabilities
to any computer with a USB port. The board is a USB 2.0 high speed device, offering the
fastest speed available with the USB bus. It is fully compatible with both USB 1.1 and USB
2.0 ports. The card is plug-and-play allowing quick connect/disconnect whenever you need
additional I/O on your USB port.
The board features 48 bits of TTL-compatible digital I/O with high-current capabilities. Each
digital port can be programmed to accept inputs or to drive outputs in 6 groups of 8-bit ports.
Power is supplied to the card via the USB cable or for higher current capabilities, external
power may be used. The I/O wiring connections are via two industry standard 50-pin
connectors. For external circuits, fused +5VDC power is available at each I/O connector on
pin 49. There is one resettable fuse per connector. The resettable fuses are rated at 0.5A.
All I/O lines are buffered by a type 74ABT543A tristate buffer transceiver capable of
sourcing 32 mA or sinking 64 mA. The buffers are configured under program control for
input or output.
I/O Lines are jumper selectable with pull-ups (to +5 VDC via 10K
Ω
) or with pull-downs (to
ground).
Unlike most USB digital I/O products which primarily use a human interface device (HID)
driver, we provide an easy to use, Windows-based, custom function driver optimized for
maximum data throughput. This approach exposes the full functionality of the hardware
along with maximizing the advantage of using the high-speed USB 2.0 bus.
Power is supplied to the card via the USB cable or for higher current capabilities, external
power may be used. Complimenting the high-retention USB type B connector (quickly
recognized by the orange insulator) is a factory option for a high-retention external power
screw terminal pair.
