A subsystem that behaves as an LXI instrument

This paper describes an intelligent subsystem that integrates into a larger test system as if it were a single complex instrument. Actually, the subsystem contains a controlling embedded PC and various instruments that conform to the PXIe test standard working in tight coordination to perform complex tasks. The test station computer communicates with the subsystem with a high-level IVI driver via Ethernet. LXI is an attractive choice for integrating test instruments into a larger test system largely due to the interconnection simplicity provided by Ethernet. LXI is typically used with individual instruments, not a group of instruments controlled with an embedded PC. While it is possible to control all of the PXIe instruments directly from the main test station computer, the task of integrating the functions would need to be repeated for each test system design. A novel solution is to configure the subsystem as a single LXI compliant device with extensive localized and reusable capabilities. The PXIe chassis that houses the subsystem instruments is controlled with an embedded PC, which hosts an LXI discovery service and IVI remote driver. The services are implemented using C, C# and .NET on an embedded 64-bit Windows 7 operating system. By developing LXI code that runs on the embedded PC housed within the PXIe chassis, we treat the entire subsystem as an LXI compliant device. This paper shall discuss the high level API with which the subsystem is controlled, as well as the architecture of the services running on the embedded controller that make the subsystem LXI compliant.