National Instruments 7334 - Manual (Page 19)

Chapter 3 Hardware Overview
7344/7334 Hardware User Manual 3-4 ni.com
The RTSI connector provides up to seven triggers and one high-speed clock
signal to facilitate synchronization between multiple National Instruments
products. Typical applications of the RTSI bus include triggering an image
acquisition or DAQ measurement based on motion events, or capturing
current motion positions based on events external to the motion controller.
The RTSI bus can also be used for general-purpose I/O. Refer to Chapter 5,
Signal Connections , for details about RTSI connector signals.