Configuring PXI Trigger Lines in Linux


Use the resources below to guide you through the setup of your PXI controller in Linux. This article discusses how to identify and route trigger bus lines on your PXI backplane.



Use the nipxiconfig command-line utility to configure your PXI system in Linux and reserve/route PXI triggers. This utility is shipped with all NI drivers providing support for PXI(e) hardware in Linux Desktop.

Using nipxiconfig

In order to use nipxiconfig, ensure the following: 

  • You need to run as root (su -)
  • nipxiconfig is designed to call with one command with no feedback questions (nipxiconfig --com-m and [parameters]...).
  • For a complete list of commands, execute the following command nipxiconfig --help.
  • For detailed help run man nipxiconfig to access the manual pages of the nipxiconfig which provides descriptions of error codes and syntax.

Example Using nipxiconfig

This is a simple example of configuring a PXIe System that consists of a PXIe-1065 chassis with a PXIe-8108 embedded controller connected via MXIe-x4 to a PXIe-1085 Chassis.

Figure 1. Example System


Below is the procedure to configure the above system. 


2.1 Display the PXI System

  1. On your Linux PXI controller, use the --list-system -v  command to view your chassis, controller, and MXI connections, as shown in the image below.

In this example, the PXIe-1065 is referred to as Chassis 1 and PXIe-1085 is referred to as Chassis 2.

Note: PXI Express hardware will identify and display automatically. For certain older PXI products, the hardware must be manually identified. For instructions on doing this, use nipxiconfig --help to view the utility's help documentation.

Figure 2.   Displaying system hardware using nipxiconfig in CentOS 7


2.2 Trigger Reservation and Routing

Triggers need to be routed across the segments explicitly when using drivers that do not provide automatic routing. The nipxiconfig utility in Linux can be used to route triggers across segments. Below is an example of routing triggers for the PXIe-1085 chassis that was used in the above example. For more information on PXI timing and triggering, see Using PXI Timing and Triggering Functionality.


  1. Use the --list-triggers command  and specify the chassis number to view the trigger buses for your chassis.

    The image below shows the trigger buses for both the PXIe-1065 (Chassis 1) and PXIe-1085 (Chassis 2). Currently, there are no triggers reserved, so all the boxes are unchecked and displayed as available.

Figure 3. Trigger bus view using nipxiconfig on CentOS 7


  1. Use the --reserve-trigger command  and specify the chassis number and which trigger line to reserve. 

For example, if you want to reserve PXI_Trig1 from Chassis 2, use the following command:

--reserve-trigger 2 1

  1. Use the --list-triggers command  again to view the updated trigger buses. The results are shown in the image below.  

Figure 4. Reserving PXI_Trig1 in chassis 2 using nipxiconfig on CentOS


  1. Use the --route-trigger command and specify the chassis number, the trigger line, and the bus to use as the source to route the trigger.

For example, now that PXI_Trig1 is reserved, suppose you want to route it from segment 3 towards slot 1. At the same time, you will route PXI_Trig3 from the middle segment outwards. To do this, use the following commands:

--route-trigger 2 1 3

--route-trigger 2 3 2

  1. Use the --list-triggers command  again to view the updated trigger buses. The results are shown in the image below.

Figure 5. Route PXI Triggers using nipxiconfig on CentOS 7