All slots on the same PXI bus segment share eight PXI trigger lines. You can use these trigger lines in a variety of ways. For example, you can use triggers to synchronize the operation of several different PXI peripheral modules. In other applications, one module located in the system timing slot can control carefully timed sequences of operations performed on other modules in the system. Modules can pass triggers to one another on the lines, allowing precisely timed responses to asynchronous external events the system is monitoring or controlling.

The PXI trigger lines from adjacent PXI trigger bus segments can be routed in either direction across the PXI trigger bridges through buffers. This allows you to send trigger signals to, and receive trigger signals from, every slot in the chassis. Static trigger routing (user-specified line and directional assignments) can be configured through Measurement & Automation Explorer (MAX). Dynamic routing of triggers (automatic line assignments) is supported through certain NI drivers like NI-DAQmx.

Note Although any trigger line may be routed in either direction, it cannot be routed in more than one direction at a time.

With the Timing and Synchronization upgrade, PXI trigger lines can also be routed to I/O ports on the rear of the chassis. This allows you to send trigger signals to, and receive trigger signals from, devices in other chassis. NI drivers such as NI-DAQmx must be used to route triggers between chassis dynamically; routing triggers between chassis using static routes defined in MAX is not supported.

Figure 8. PXI Trigger Bus Connectivity Diagram


Note Dotted line connections are available only with the Timing and Synchronization upgrade.