# Precision I/O

The Cognex Communication Card and the Vision Controller both support 8 discrete input lines and 16 discrete output lines, and they support connections to external devices through an I/O terminal block or a breakout cable. The card also supports an Ethernet port for communication with industrial Ethernet devices using a supported Industrial Communications protocol.

Note: See the Communication Card Installation Manual for details on how to install the hardware and connect it to external devices.

The Cognex Communication Card allows you to create a configurable I/O event system capable of handling the signals between your vision application and the discrete I/O equipment in your production environment, without interaction with, or intervention from, the host PC as your vision application operates. This can avoid common issues related to Microsoft Windows latency when processing I/O events using typical I/O solutions.

Within a Task, the Read IO and Write IO allow you to read and write to the I/O lines, and the Cancel Event and Schedule Event allow you to handle events.

There are two ways to configure the I/O events: The Precision IO Configuration Editor, or the VisionPro programming interface, using the Cognex Communication Card API.

Note: When using either the Precision IO Configuration Editor or the Cognex Communication Card API, this type of configurable I/O event system is called precision I/O. Using a Factory Floor Protocol does not qualify as precision I/O because they require interaction with the host PC.