1. Where do these products originate?
2. What power supplies do the SOAR USB products require?
3. Why are they called SOAR?
4. How do you select ARINC 429 channel speeds?
5. What's the advantage of optically coupled ARINC 429 receivers?
6. What are the advantages of USB connection to the PC?
7. Is USB 2.0 an advantage (or required)?
8. What are the issues with using USB for PC connection?
9. What does the ZEUS for Windows software cost?
10. Will I need extra licenses to run ZEUS in more than one place?
11. What are these 'Sets' you talk of?
12. How much Engineering Units support does ZEUS for Windows provide?
13. How many RTs can the 1553 units represent?
14. How do I get to see my data?
15. Can bus data be recorded and replayed?
16. Can I change output data while my test is running?
17. Are the A429 channels multiplexed?
18. Are 1553 Mode Codes supported?
19. Are Broadcast messages handled correctly?
20. My test rig is in a 19” rack. How do I install one of your units?
21. What's all this about two APIs?
22. Which operating systems support ZEUS for Windows?
23. How do I choose which product is right for my requirement?
24. Can I output dynamically changing data or are the cycle always static?
25. Is it possible to plot Rx or Tx data to a graph?
26. I'm keen to take my interest in these product further. What do I do next?

Where do these products originate?

All Airflair's USB connected databus test products are designed, developed and built by Airflair in Somerset, in the West Country of England. The products are all directly supported by the team which designed and developed them. We are proud of the range (in a modest, British, sort of way) and we enjoy working with our customers to put them into use as effective and efficient responses to real testing problems.

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What power supplies do the SOAR USB products require?

All our USB connected databus testers are USB Bus Powered. This means that they draw all the power they need from the USB cable which connects them to their 'host' computer. The only exception is the USB 429/1553 device; when running with all channels fully loaded this requires more power than a standard PC USB port is able to supply. The remedy here is simple. When running one of these devices fully loaded you either connect it to a second USB port on the host computer (the only purpose of which is to supply additional power) or to the (supplied with the unit) mains adapter. As a final option, the USB 429/1553 can be run with a single USB connection to a PC capable of providing the necessary power on a single port. (We know of very impressive, rugged, laptop which, as a matter of manufacturer's specification, meets this requirement.)

Other than the USB 429/1553, though, simply connect your unit using a normal USB cable.

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Why are they called SOAR?

This description came from one of our customers. It stems from the fact that (see previous FAQ) the units connect to the PC via one cable (USB) and to the rest of the world, typically, by another (ARINC 429, say) which connects to the other ed of the box. So, the unit itself appears as a lump on the cable, in a way reminiscent of the `soap-on-a-rope' which used to hang in the showers. (Maybe we're showing our age here!). A short step takes you from soap-on-a-rope to SOAR.

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How do you select ARINC 429 channel speeds?

For the receivers, you don't. The receiver channels adapt automatically to the speed of the data they're seeing – and report the result back to the host PC with the data itself. For the transmitters, the speeds are set (in ZEUS) as properties of the channels. In addition to selecting high or low speed operation, a range of settings around the nominal figures (100 and 12.5 KHz) are available for use. The same capabilities are also available via the APIs.

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What's the advantage of optically coupled ARINC 429 receivers?

Optically coupled receivers have two main advantages: They're very robust (but please don't test this assertion by connecting them across two phases of your ac supply!) They have excellent common noise rejection The opto-couplers which we use are high sensitivity, high speed, devices. This allows them to comfortably meet the ARINC 429 input impedance requirements.

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What are the advantages of USB connection to the PC?

Many and various! Which of these is most significant will vary, so in no particular order: You can use the equipment with any modern (i.e. USB equipped) PC You don't need to open up the PC to `install' the test gear. Equally at home with desktop or portable PCs Plug and play makes it easy to move from one PC to another Allows the use of robust, easy to use signal connectors (unlike, for example) PC Card alternatives Easy to connect multiple devices to one PC (although we do recommend a dedicated port for each device) Future-proof. ISA slots have gone from 'commodity' computers. PCI slots seem to be following. PCIe slots are limited – and quite often taken up by other add-ons. USB connections are plentiful an modern PCs – and USB is likely to be with us for a very long time.

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Is USB 2.0 an advantage (or required)?

No. The USB interface operates at the higher USB 1 speed of 12MHz. It will do this even when attached to a USB 2.0 interface. The bandwidth available from a 12MHz USB interface is quite adequate for all our USB connected devices.

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What are the issues with using USB for PC connection?

There are some minor issues with latency. Mainly these result from driver/interface issues and not from the throughput of USB itself (even at 12MHz). But in any case, all of these issues tend to be overwhelmed by the use of the Windows operating system, which really wasn't designed for this sort of hard real time application. But, Windows has lots of advantages – and Windows PCs are low cost and readily available. So, the key 'speed' feature which is really of concern is making the system as a whole cope with Windows lack of responsiveness to outside world signals. The response to this concern is an `intelligent' unit and ample buffer storage, both featured in all our USB connected equipment. The other issue with the use of USB is power consumption. A standard USB port is (as a matter of specification) rated at 500mA (at +5volts). Fine for a mouse or keyboard – and fine too, of course, for printers and the like which provide their own power. But a bit on the mean side for a lot of avionics databus interfacing. 1553 interfaces are a particular challenge, especially when fully loaded (The transceiver power consumption is roughly proportional to the time for which it, as opposed to external equipment, is driving the databus.) The response to this issue is designing for minimum power. We've done this with some success; all our units will operate on power from the USB bus only. All except one can be operated at any loading on the power drawn from a single USB port. The exception (the USB 429/1553 multi-protocol unit) may in some cases need to supplement its main USB interface's 500mA with power drawn from a second USB port.

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What does the ZEUS for Windows software cost?

Nothing! Every USB connected databus tester is supplied with ZEUS for Windows bundled as part of the package. That way, even if you plan to develop software of your own in the long term, you can be up and running and doing effective testing within minutes. (And you may well discover in the process that you don't need to write any software after all)

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Will I need extra licenses to run ZEUS in more than one place?

No. All that the license asks is that you only run the software in connection with the use of Airflair's hardware devices. You may create multiple installations – and use them simultaneously. That way, one person (or more) can be preparing for tomorrow's tests, one person can be using ZEUS with the hardware to do today's test and any number of people can be using it to analyse yesterday's results.

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What are these 'Sets' you talk of?

Sets are a powerful mechanism for controlling output data. You can create as many Sets as you like (for each output channel with ARINC 429 or Bus Controller and RT with 1553). Each Set is a complete set of output traffic, which you can activate in a number of ways (including a single click on a control you design onto a display page). Sets can differ in many ways, including: Minor and Major cycle periods (A429 and 1553 BC) The labels (A429) or messages (1553 BC) on the bus The data content of the labels/words (A429, 1553 BC and RTs) So, when you change to a different Set you can make widespread changes to the data the tester is creating, all co-ordinated and synchronised. You can, of course, then go on to change individual items of data as and when you wish. Typical uses are to represent different operational phases (e.g. Initialisation => Standby => Run) or the stimulus requirements of different test steps.

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How much Engineering Units support does ZEUS for Windows provide?

Just about all you could ask for (and if you want to ask for anything more we will be happy to hear from you!). For every data word on every A429 channel (input or output) and every 1553 word (internally or externally generated) you can define: Any number of bit fields (using a simple `drag the cursor' graphical technique) The conversion type, taken from a list of 19 different types. The bit weighting (for 'analogue' parameters) The units of measure of the resulting data (again, for 'analogues'), taken from a drop down of 31 commonly used units or entered directly Literal strings to be associated with each state of a discrete bit or enumerated list field. We call the resulting entities 'Data Items' and, unless you're feeling masochistic and decide to work in raw Binary or Hex, these are what you'll be working with when you enter or display information. You can have as many Data Items in a word as you want – and you can freely mix the types too. So, you can merge into a single word some discretes representing toggle switches, enumerated lists representing rotary switches and analogue values representing 'pots'. Or whatever; you choose. Drag and drop an input Data Item onto a display page you're designing and it becomes an instrument, which will be continuously updated at run time. Drag and drop an output Data Item and it becomes a control, allowing you to change the value of the Data Item at any time while your test is running. (No need to worry about the rest of the word the Data Item comes from; everything gets merged together when you change any Data Item, updating the entire word in the physical output stream.) In addition, you can 'drill down' to your defined data items from the built in databus search facility, and have them shown individually in views of recorded data.

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How many RTs can the 1553 units represent?

As many as you want, in any combination. You can also choose to emulate any RT(s) on one or the other half of a dual redundant bus (along with both halves, or neither). RT emulations can be combined with Bus Controller operations – again, in any combination. In addition, the Bus Monitor function is always, again without limitation, available.

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How do I get to see my data?

ZEUS for Windows allows you to define an unlimited number of display pages, for use when you are running a test.

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Can bus data be recorded and replayed?

Yes. During a test run, any combination of data, filtered to word level for A429 and message level for 1553, can be tagged for logging. Output data can (and usually should) be tagged for recording too. Logging takes place at full bandwidth (i.e. not sampled) and can continue until your hard disk is full. Setting the filters to exclude information in which you have absolutely no interest will reduce the size of the resulting file and is recommended. Data is in any case stored in 'raw' form, to further reduce file size. Once data has been recorded (in a 'logfile') it can be replayed on screen at various rates. If necessary, new display pages, and even revised Engineering Units conversions, can be defined prior to replay. You can use normal run time facilities for pausing updates, changing display page etc. Special versions have been created from time to time to allow physical replay through the hardware. These allow data recorded from receiver channels (or messages) to be replayed through the output hardware. To get the best fit of capability with your requirements we usually provide a bespoke implementation of this functionality. If you have such a need, please contact us for more information.

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Can I change output data while my test is running?

Yes. Simply include the Data Item (or raw word) on any display page. You can then click on it during a test run and change the data and despatch it to the output from the resulting dialogue box. There is no limit to how many 'controls' like this you can have. If your control relates to a Data Item rather than a raw word then the changed value is automatically merged back into the word when you've entered it, then sent to the hardware. So, at run time you have no need at all to keep track of which parameter 'lives' in which word, or what else lives there too. In addition, you can use the powerful 'Sets' facility to make single click, wholesale, co-ordinated changes to output data. You can even do this on multiple channels/RTs from the same button 'event'. And/or you can define a 'hot key' to have the same effect.

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Are the A429 channels multiplexed?

Certainly not! Terrible idea!

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Are 1553 Mode Codes supported?

Yes. Full mode code support is provided within the limitation of the dual redundancy that the hardware supports. (In other words, `selected transmitter' mode code are not supported.)

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Are Broadcast messages handled correctly?

If they are present in your system, they will be handled correctly.

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My test rig is in a 19” rack. How do I install one of your units?

There are two choices here: Find some way of securing the standard enclosure to a shelf, bulkhead, 1U module or (entirely practical, especially for the smaller units) a suitable cable loom. Tell us how you'd like it configured (USB and I/O connectors on front/rear) and we'll supply the equipment in a 1U 19” module. This would normally use the standard I/O connectors, but allows others to be used instead.

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What's all this about two APIs?

Its true! Two, fully documented, APIs are available, as follows:

The 'Classic' API uses the functionality of the .DLL which interfaces to the USB link. All the commands to which the equipment responds are available for use by user written software. The data structures provided with this API make operation of both ARINC 429 and 1553 buses a good deal simpler than `doing it in the raw', but you will need to construct your minor cycles and so on yourself. Use this API for C, Delphi etc projects. We will provide any support you need, although if you want us to write the entire application for you we may ask for a modest contribution to the food and clothing fund :-)

The `.NET' API exposes the objects within the ZEUS for Windows software, making them available for use in your code. If you're using a .NET language this approach can save you a lot of time and effort and is the way to go. Please feel free to contact us for more information about software creation. Please keep in mind, too, that we see our equipment as just a part of your test solution. We have tried very hard to make our standard ZEUS for Windows package meet as many needs as we can, without compromising usability. And we (and our customers) believe that, by and large, we have succeeded. There is a very great deal more, though, that can be done with the basic architecture of ZEUS – and (unlike many other test equipment suppliers) we are more than happy to bring out this latent capability for your application. There are a variety of ways this can be organised. We will work with you to identify the best one and take it through to successful operation. Please call or e-mail to discuss your requirements.

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Which operating systems support ZEUS for Windows?

ZEUS for Windows was created with a view to use under Windows XP. This is what we recommend. We are 100% committed to making the range work under Vista/Windows 7 too. ZEUS will also work with Windows 2000, but NT does not support USB, so does not support the products (even at the hardware/API level).

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How do I choose which product is right for my requirement?

A good place to start is the comparison chart on the reverse side of our `Meet the Family' flyer. Alternatively, or to discuss both standard and `special' requirements, please e-mail or call us.

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Can I output dynamically changing data or are the cycle always static?

 Yes (on supported hardware). 'Functions' can be assigned to transmit items in the Tx cycle sequence tables which incrementally work through a set of predefined values which can be loaded from a simple .csv file.

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Is it possible to plot Rx or Tx data to a graph?

Yes. ZEUS 3.x provides a new 'Chart' display item which allows you to link up to 8 data items for plotting on the display. The chart can be configured to display 'rolling values' allowing you to visualise historic data as your test runs.

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I'm keen to take my interest in these product further. What do I do next?

Just e-mail: info@airflair.co.uk  We'll get back to you. Really soon!

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