The PISO-P64 has 64 channels of optically isolated digital inputs, arranged into four banks. Each input channel use a photo-coupler input which allows either internal isolated power supply or external power selected by a jumper. Isolated input channels 0-15 are designed into group A, channels 16-31 are designed into group B, channels 32-47 are designed into group C and channels 48-63 are designed into group D. The power supply of the input port may use the external power or the power from the PC side using a DC/DC converter. The board interfaces to field logic signals, which eliminates ground-loop problems and isolates the host computer from damaging voltages. The PISO-P64 has one 37-pin D-Sub Connector and one 40-pin male header. Users can connect the digital signal through the second D-Sub connector. Each D-Sub connector contains 32 input channels.