USB-I/O Interface Adapter GPIO-24. Programmer's Reference Manual.
6.1. Digital Input Event
Byte 4: PHASE of GPIO_SET_IN_CFG command defines the conditions when GPIO-24 adapter sends GPIO_EV_IN event.
This byte can take on one of 6 different values:
GPIO_IN_EV_NONE (0x00) – No events are sent for current pin.
GPIO_IN_EV_LEV_0 (0x01) – Events are sent when pin has logical "0" on its input.
GPIO_IN_EV_LEV_1 (0x02) – Events are sent when pin has logical "1" on its input.
GPIO_IN_EV_RISING (0x03) – Events are sent when input value changes from logical "0" to "1".
GPIO_IN_EV_FALLING (0x04) – Events are sent when input value changes from logical "1" to "0".
GPIO_IN_EV_CHANGE (0x05) – Events are sent when input value of the pin changes.
