Deploying portable PXI systems aboard naval vessels for testing of proprietary computer hardware

Author(s):
Richard van der Weide - Royal Dutch Navy

Industry:
Government/Defense

Products:
PXI-7811R, Professional Development System, PMA-1115, PXI-8106, FPGA Module, PXI-1042Q

The Challenge:
Replace an outdated and obsolete proprietary naval computer test system, used on-board of navy ships

The Solution:
Use commercial-off-the shelf components such as NI PXI and the NI PMA-1115 together with LabVIEW FPGA to interface to the dedicated computer bus

Replacing dedicated hardware with commercial off the shelf customizable hardware

Computer control systems on the Royal Dutch Navy ships were introduced almost thirty years ago. Some of these systems still operate today; others have been updated, but still use the same system architecture. The system consists of a large mainframe processor, which communicates over a special 8-wire serial bus called TMIO/TMCU, with some external connected auxiliary hardware, such as tape-devices, memory, printers, display consoles, weapon systems, radar, captains’ horizontal display console and much more.

The mainframe itself does not have a direct I/O console; the program is loaded from a tape or compact Flash device and after a load command the program is executed. To maintain, test, debug and setup the mainframe, a special purpose portable interface computer (PICO) system is used, that uses dedicated hardware to interface directly to the 8-wire serial bus. This PICO system is now outdated. Onboard each ship we have several of these PICO systems, but because spare parts can no longer be ordered, more and more systems have stopped functioning. Therefore we were required to replace approximately 50 systems. The system will not only be used by the Royal Dutch Navy, but maybe for other countries that use the same computer architecture as well.

The main functional requirements of the PICO replacement are:

-        Communicate via teletype/telnet session with the mainframe over the special TMCU bus, to send messages, command and parameters

-        Emulate devices attached to the TMIO/TMCU bus, such as tape or compact flash readers, to load programs to the mainframe

Besides this, the system needs to be transportable and rugged to be taken to ships and maintenance facilities.

When looking for a replacement system we researched different solutions, such as a laptop with special custom hardware, PCI-based and PXI based industrial computers

We discovered several disadvantages of laptop systems. These are not generally seen as measurement devices by the navy crew and are easily also being used as e-mail client, web browser, etc., and loaned to other crew members during their long stays at sea. It can easily happen that software is damaged by other software installations, or measurement files get lost. Both the laptop and the PCI-based solution were lacking modularity, to enable future expansion and were also less rugged.

The PXI-1042Q  with the PMA-1115 Keyboard and Monitor Accessory is immediately recognized as a special measurement device. The Windows XP operating system can be narrowed for users, so they will only have access to the executable measurement application.

The PXI system is a far more ruggedized system and still a modular expandable PC-based platform. Because of this form we can expect to obtain replacement parts for extended periods, as opposed to less rugged laptop parts. We can add functionality and modules to the system later if we need to do additional tests, including serial, SCSI and GPIB interfaces.

Finally the PXI system would be at least 5 times more cost effective as compared to the dedicated/customized (fixed) laptop solution, since we can leverage off-the-shelf LabVIEW FPGA technology to interface with proprietary protocols, where the laptop would need expensive custom-build hardware.

Developing the application:

It was very advantageous to discover that with my previous LabVIEW experience I was able to develop applications for FPGAs using the LabVIEW FPGA module. The application consists of these parts:

-        Input task (runs on the FPGA)

-        Output task (runs on the FPGA)

-        Protocol conversion to TMCU from teletype/loading of test software commands (runs on the FPGA)

-        Front ends for tasks like telnet, software loading to mainframe and other tasks

While developing the application we needed to understand the whole system. Because the mainframe was developed long ago and most of the original developers of the system no longer work at the supplier, we missed vital information, like source code and the functioning of the test system, what commands and protocols the bus defined, or source code.

Here the NI PXI-7811R FPGA board came at hand, by logging the messages during the communication between various devices. We went through a reverse engineering process and determined the low level commands, data-packet size, etc. Now it became possible to emulate these devices. For example we can detach the compact flash program loader and load our test program into the mainframe, and instruct it to do a memory test. This is comparable with to desktop PC, of which we disable all external and internal devices, like the hard drive, and now we can boot via our PXI system, emulating the hard drive. This way it is much easier to find errors and debug the system for faulty cards, because we can switch off function by function and run test programs developed in the past.

More advantages above basic functionality

Besides emulating devices, and interfacing over a telnet like interface with the mainframe we found the LabVIEW solution has more advantages we did not immediately anticipate. For maintenance purposes we plan to use the built-in LabVIEW web-interface, for remote debugging from the shore, while the ship is at sea. And finally we can have quick looks at the system. In this mode the PXI system logs all data of messages to and from the mainframe and performs real-time analysis on them. In the past we needed a special program for this that stored the data on compact flash. To retrieve the data, we needed to shutdown the mainframe, extract the data from the compact flash and start the mainframe again.

Accurate shooting with a weapon system

Another big benefit of the PXI system is that we can now monitor the bus traffic on the fly, by logging and real-time analyzing. This enables us to take a quick look at all navy systems. Test firing runs with drones can now in real-time be analyzed. The Goalkeeper defensive weapon system can autonomously track enemy missiles, ships and aircrafts by radar and then fire up to 4200 bullets/minute at them. During a test firing a drone is pulled by an aircraft and flying towards the ship. In the past a quick look analysis was quite difficult to do, as the ship is sailing at a certain compass heading; the radar system reports in polar coordinates relative to the ship and the gun reports in X-Y coordinates. The recording of all these data was done off-line, and analyzing is very time-consuming which could sometimes take days to weeks. Now we can use the PXI to log all the messages from the goalkeeper, ships heading and the radar and in real-time see how much the drone flight is aligned with respect to preferred drone flight path. Now as the aircraft turns, the captain can already see the test results.

The extensive functionality of LabVIEW, in this case to transfer coordinate systems into other coordinate systems, together with the presentation capabilities and the PMA-1115 are a key part in this. Also we obtain a very substantial time gain.

The PMA-1115 integrated display on the PXI chassis makes this a truly complete, portable and rugged off-the-shelf solution. A big advantage of the system is that the extensive and broad LabVIEW functionality, such as conversion of coordinate systems, built-in web interfaces and much more.

Because of my earlier programming experience for developing applications running on Windows OS’s, I could very quickly develop the custom communication protocol on the PXI-7811R FPGA module because the programming paradigm is the same.

We plan to extend the functionality of the PXI system to other areas in the future.

 

For more information, contact:
Royal Dutch Navy
Defense Materieel Organisatie
C4i Marinebedrijf
Mr. R. Van der Weide
Het Nieuwe Diep 5
1781 AC  Den Helder
The Netherlands

T +31 (0223) 656 921
E-mail: R.vd.Weide.01@mindef.nl
Web:    www.marine.nl

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