The Microsmith T-DIO-64 model 941101 is a DC I/O module which is housed in a rugged ABS 94-VO DIN rail mount shell. This module is designed to act as a sink for resistive or inductive loads of up to 500 mA per channel.  Each channel has a comparator input connected to its open drain output; therefore if the output is left "Off", that channel functions as an input. The input threshold is five volts and each one is internally pulled down with a 90K resistor. This allows these inputs to be actuated with a dry contact, (i.e. any PNP (sourcing) sensor, or any NPN (sinking) sensor that has a pull-up resistor). The comparator may also be used as a diagnostic tool to detect the absence of a load.The terminals from each module are connected to either a high quality screw-type terminal block which allows easy installation without requiring special tools, or to dual-row IDC type headers. Sample C code is included which allows all 64 channels to be used as inputs or outputs.