MITS - 88-PCI    Process Control Interface Board
Probably reflecting upon the companies early roots, it was the first company to offer an S-100 board for process control systems.

This board was for users wishing to control the operations of almost any electrical or mechanical device with an Altair 88-PCI board. Through the use of relays, opto-couplers and software, the PCI board received process information and transmitted control signals. A complete interrupt structure and handshake configuration was included, both were software controllable.
 
Possible applications included monitor environmental conditions (heat, light, humidity} in the home or laboratory; control devices; control automatic sorting and grading of products on an assembly line; read and respond to scientific test results, such as changes in pressure, pH or viscosity etc.