User manual

Chapter 3 Software Overview

7-wire trigger bus. Each device that works with a RTSI bus interface

contains a number of useful signals that can be driven onto, or received

from, the trigger lines. Each device is equipped with a switch with which

an onboard signal is connected to any one of the RTSI bus trigger lines

through software control. By programming one device to drive a particular

trigger line and another device to receive from the same trigger line, you

can hardware connect the two devices. Use the RTSI Bus Trigger functions

described in this chapter for this type of programmable signal

interconnection between devices.

Through the RTSI bus, you can trigger one device from another device,

share clocks and signals between devices, and synchronize devices to the

same signals. The RTSI bus also can connect signals on a single device.

To specify the signals on each device that you can connect to the RTSI bus

trigger lines, each device signal is assigned a signal code number. Make all

references to that signal by using the signal code number in the RTSI bus

trigger function calls. The signal codes for each device that can use the

RTSI bus trigger lines are outlined later in this section.

Each signal listed in this chapter also has a signal direction. If a signal is

listed with a source direction, that signal can drive the trigger lines. If a

signal is listed with a receiver direction, that signal must be received from

the trigger lines. A bidirectional signal direction means that the signal can

act as either a source or a receiver, depending on the application.

E Series, DSA, 660X, and 671X RTSI Connections

For information regarding signals on the E Series, DSA, 660X,and

671X devices that you can connect to the RTSI bus, refer to the

Select_Signal

function description in the NI-DAQ Function Reference

Online Help file.

Note

If you have a PXI-DSA board in slot 2 (star trigger controller slot), do not drive any

signals on RTSI 6 from other modules in the chassis. You can use other RTSI lines.