The IA-3324 is an RS-232 based digital I/O & counter controller. The digital I/O is divided into three bytes of 8 bit each, while each byte may be used as an input or output port (software setting). Reading the input channel may be done either by polling or by COM interrupt triggered on any data change. The counter supports both event counting and quadrature encoder input. The module is controlled through a standard PC RS-232 COM port and responds to a simple ASCII command-set.