PC Board Optically Isolates Data Inputs

A PC/104 board, the Model 104-II32-4RO is a 36-channel utility board that contains 32 fully optically isolated digital inputs with change-of-state interrupt generation and four electromechanical relay outputs. It enables connections to a range of devices such as sensors, switches, controllers and powered circuits. The inputs can be driven by either dc sources from 3- to 31-V or ac sources with frequencies of 40 Hz to 10 kHz. Each input circuit includes a jumper-selectable filter to accommodate ac inputs, but is also useful for slow dc inputs in noisy environments. The filter can be manually disabled to improve the board’s typical response time to 10 ms when used with faster dc inputs. To prevent erroneous input-state change detections and interrupts, Schmitt triggers provide a reliable logic signals to the computer interface. The board is supported for use in most operating systems and includes a free DOS, Linux and Windows 95/98/Me/NT/2000/XP/2003 compatible software package. Price is $295 each.