The design and development of LXI trigger box

Triggering is a key issue in the distributed test system. As a basis for the distributed test system, Networked Test Instruments are required to support more trigger modes^[1]. But in the distributed test system, sometimes each instrument has many different trigger modes. It leads that instruments can´t directly trigger each other. Therefore, these different trigger modes are difficult to be managed for system. Now the LXI trigger box is introduced in the paper. It is based on LXI bus (LAN-based eXtensions for Instrumentation) and supports a variety of LAN trigger modes. The instrument connected on the box can visit the LAN and trigger other instruments. The LXI trigger box can manage all kinds of Networked Test Instruments´ trigger problems, which brings the convenience to build a distributed test system. The Trigger Box supports the IEEE1588-2008 Precision Time Synchronization Protocol through the timestamp information carried by the LAN message. The trigger time of instruments can be specified, which is very important to the occasion that requires precise time-triggered coordination between instruments. The average synchronization accuracy of Trigger Boxes is ± 13ns which can meet requirements for most applications.