# Precision I/O Events

A single precision I/O event is defined by its name, its causes and its responses.

For example, the following event immediately sets the Output 0 line High for 10 milliseconds when the Cognex Communication Card detects that Input 0 is High:

Name | Cause | Response
--- | --- | ---
"Part Present Sensor" | Input_0 High | Output_0 High, 10 msec

A more complex event can support a collection of causes and responses. In this example, the "Stop Inspections" event will occur whenever Input lines 0, 1 or 2 are set to High:

Name | Cause | Response
--- | --- | ---
"Stop Inspections" | Input_0 High | Output_0 Low
| Input_1 High | Output_1 High, delay 10 msec
| Input_2 High | Output_1 Low, delay 40 msec

Whenever any of these causes occur, the event will generate all the responses, specifically by setting Output 0 line to Low and pulse Output line 1 for 30ms after a 10ms delay.

Once your event collection has been defined with causes and responses, you enable the event system and allow the Cognex Communication Card to respond to signals detected over discrete I/O devices.

There are two different methods to configure an event system to schedule and respond to I/O transitions without involving the host PC (your vision application can contain any number of precision I/O events):

- Precision IO Configuration Editor
- Configuring Precision I/O Events via API