The PMC-DIO24 is a simple 25-bit discrete I/O interface board. The host side connection is PCI based and the external I/O interface is variable (see below). The external interface includes 24 signals that can be arbitrarily programmed as either input or output and one signal that is input only.
The 24 programmable signals are divided into three groups of eight pins each; Port A, Port B and Port C. Ports A and B are each programmable as all inputs or all outputs. The Port C signals are individually programmable. Although the PMC-DIO24 provides extensive flexibility to accommodate many user applications, custom interfaces exist which may not conform to current PMC-DIO24 interface options.