The ISO-813 card has 32 12-bit analog input channels. In reality, this is implemented as a 32-channel multiplexer that feeds into one analog-to-digital (A/D) converter. The trick with this card is that you need to tell the multiplexer which channel it should be reading, set up the gain (1x, 2x, 4x, 8x, or 16x), wait for the multiplexer and A/D to stabilize, and then trigger an A/D conversion. When the A/D conversion is complete, you can read the 12-bit result from an I/O port.