ISA BUS 8 bit I/O CARD

Nowadays the industrial plants, automated machines and processes use HMIs (Human-Machine Interfaces) to make more friendly to operators the use of these equipments. There is a family of software that is know as SCADA (Supervisory Control And Data Acquisition) of which Wonderware is one of the most common. These applications run on a PC and they communicate with a machine to display data or to activate, modify or to acknowledge alarms.

PLCs are expensive for the small range of machines and processes. For less complicated process I suggest a PC with interface boards running an application that both controls and monitors the machine. General Motors uses a software called OpenControl that has a special kernel that shares the CPU with WinNT 4.0 kernel to control in real time the gantries and the buffers on their crankshaft lines in their most modern engine plants.

I made my own ISA I/O card and wrote a simple Windows based app to control it. I am planning to hack a RC car to control it from this computer, but the potential calls for more.

This is the schematics (version 1)

This is a more simpler version. If only one port is to be used, 7406 and 7432 can be replaced with transistorized version of these gates. In The upper right corner, a transistorized version of a OR gate is proposed. An inverter is simply made with a biased NPN. For up to eight ports can be adressed using the same address decoder, Y0 thru Y7 will select with buffer to gate. Valid Addresses are: 200h 220h 240h 260h 280h 300h 320h 340h

This is another schematics (version 2)

A more complex version, because it must use 4 ICs.

This is my Industrial PC (homemade)

The blue plastic box holds a 386SX PC

The ISA I/O card is on the right

I/O board with LEDs to indicate status of I/O bits

My windows app running on Win 3.1 (made with Delphi 1.0)