The LXI functions can be examined and verified on measuring devices using a test solution consisting of hardware and software. A connection to the network helps to ensure that the test runs automatically.
The LXI functions of a measuring device can be verified using a special hardware and software solution. The advantage of the Kerberos system developed by TSEP is that the hardware is not considered in isolation, but that the software is also an integral component. The test platform can be used to test both hardware and software. On the hardware side, all the necessary components for testing are included. The user can connect the Device-Under-Test (DUT) via several interfaces such as LAN, USB, I²C or RS232.
The hardware is controlled via one of the network interfaces. In this way, the platform creates a test environment without external influences affecting the test object. Even if a device is connected and tested via LAN, the physically separated network cards ensure that the test network and the local network are decoupled. This makes it clear that several network interfaces are available. Two of the network interfaces are routed to the outside, which are used to connect the client PC and optionally the device-under-test (DUT). Another network interface is only used internally to simulate another device in the test network. This is necessary for testing the 1588 protocol, for example. It is possible to determine whether a device can cope with several devices in the network.
Automatic test thanks to network
All network interfaces are switched internally to achieve the appropriate combination for the selected test. A peer-to-peer connection or a connection via a switch is possible. In addition, the TSEP Kerberos hardware is able to disconnect the DUT from the network or connect it to the network independently. This increases the automation of test sequences. All tests can be automated via the built-in router, as the software monitors all changes to the router. The hardware represents the server in a client-server concept.
All actions are carried out on the server, while the client is merely a tool that reflects the current status of the server and offers the option of configuring the server and starting tests. The display on the hardware shows a small statistic: this includes how many tests are included in the test scope and how many of them were successful and unsuccessful. There is also a detailed log of all actions performed by the server. This log can be displayed in more or less detail.
In the client software, the individual logs are assigned to the corresponding tests so that each test has a detailed log. This makes it possible to trace how an error occurred. A test always consists of preconditions, the actual test and postconditions. Preconditions are the settings that must be made in order to have a suitable setup to run the test. This includes router settings or whether the DUT is connected to the network at the start of the test. This means that the conditions are always the same when a test starts. There are also defined test-specific steps and finally the post-conditions are checked. This could be a validation of the IP address received from the DUT or that the DUT address has been entered in the mDNS.
Results are output as a PDF
Once all the necessary tests have been completed, it makes sense to summarize the results. The user receives this as a PDF via the client. The PDF is created on the server and signed by the server. This means that it cannot be manipulated without losing the signature. To control the server, it is also irrelevant whether the TSEP Kerberos is connected to the client via a peer-to-peer connection or simply connected in the local network. This is because the client searches for and lists all available Kerberos servers. You can connect via this list. However, each server only allows a single client. This means that an existing connection must first be closed before it can be accessed from a second PC in the network.
The platform also provides a command line tool so that Kerberos can be operated by programs or scripts. This makes regression tests possible, for example. This is helpful for continuously testing the functionalities of a device during further development. The console client can also be used to create and configure test sessions and to find all Kerberos hardware on the network. All options of the interface client are also available in the console client. Only manual tests cannot be carried out with the console, as this requires user interaction, which is only possible via the client.
Another advantage is that tests can also be logged. Individual steps are precisely tracked and documented to enable easy debugging of the problem. How detailed the recording is can be set via the client itself. Thanks to the modular structure, users can purchase customized modules to test core functionalities on their own devices.
Comparison Kerberos – LXI Conformance Test Suite
TSEP Kerberos was originally developed for LXI measuring devices. The previous software solution for testing the LXI functionality required additional hardware. A suitable router that provided all the necessary parameters for configuration was not easy to find. Individual hardware components no longer need to be searched for with the Kerberos platform. The manufacturer offers its own hardware components to increase the level of automated testing for the LXI functionalities.
Additional hardware is not required, as is the case with the LXI Conformance Test Suite, for example. The only requirement is a PC on which the Kerberos client is installed. TSEP Kerberos also ensures that the results obtained are compatible with the LXI Conformance Test Suite. Kerberos adapts changes to an LXI test. For this reason, the compatible LXI-Conformance-Test-Suite version is also specified in the information on the server. Currently, the majority of LXI components are already supported by Kerberos. This includes the “LXI Device Specification 2016” as well as the extended features “LXI HiSLIP”, “LXI IPv6” and “LXI VXI-11 Discovery and Identification”.
Planned extensions for the LXI variant are the “LXI Clock Synchronization” and the “LXI LAN Event Messaging Tests”. There are also plans to implement “LXI Security”, where the LXI consortium is making great progress. Possible updates can be installed via a USB stick. A variant of a pure IEEE1588 test environment is also planned. A merger of the Kerberos platform with Herakles, which TSEP has been continuously developing for years and is used internally to test software components, is planned for 2019.
Author / Editor: Based on material from TSEP / Hendrik Härter
