The ISO-P32C32 has 32 channels of optically isolated digital inputs and 32 channels of optically isolated digital outputs, arranged into four isolated banks. Each input channel use a photo-coupler input which allows either internal isolated power supply or external power selected by jumper. Each digital output offers a darlington transistor and integral suppression diode for inductive load. Isolated input channels 0 ~ 15 are designed into group A and channels 16 ~ 31 are designed into group B. Isolated output channels are designed into group C and group D. The power supply of the input port may use the external power or the power from the PC side using DC/DC converter. The power supply of the output port should use the external power. This interface board is easily installed in any PC. The board interface to field logic signals, eliminating ground-loop problems and isolating the host computer from damaging voltages. The ISO-P32C32 has one 37-pin D-Sub Connector and one 40-pin male header. The 40-pin to DB-37 flat cable is used to fix with the case. The user can connect the digital signal through the second D-Sub connector . Each D-Sub connector contains 16 input channels and 16 output channels.