From Technologic Systems Manuals

The TS-8820 offers 14 digital input pins. There are 8 isolated inputs that are 30 V tolerant. The 6 non-isolated inputs are 40 V tolerant.

The inputs can be polled directly through the ts8820ctl application. See ts8820ctl.c and ts8820.c for examples of how this reads from the TS-8820 registers.

With the ts8820ctl application, all 14 inputs can be read with a single command. A 14-bit value is returned in hex in a format that can be parsed easily by scripting languages. For example, the following output indicates that IN1 and IN3 are active:

ts8820ctl --getdio

When an input is activated its associated LED indicator is enabled to provide visual feedback.