Manual ETH-DIO-48
6
Functional Description
This Ethernet board is an ideal solution for adding portable, easy-to-install digital I/O
capabilities to any computer or network.
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.
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 for both connectors. The resettable fuse is 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 10KΩ) or with
pull-downs (to ground).
5VDC power is supplied to the card by an included external power adaptor via a DC power
jack, or two-position screw terminal.
Figure 1-1: Block Diagram
