 Trade Supply House and Distributor for Technical Products & Solutions © MasTec Ltd eNewsletter 2014 |
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August 2014 |
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 Etherios & Salesforce
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 USB GPIB  DAQ Bluetooth & Android  DAQ PCI & PCIe  DAQ USB |
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Welcome to our Newsletter for August 2014 This month our Product Cateory focus is:- A total of 25
companies with a huge range of DAQ, DSP, DSP+DAQ Combos &
GPIB product. DAQ, or Data Acquisition has been going on forever. All early systems were manual.The person with the Clip Board back in history was a DAQ collector and still is. When Digital computers arrived in the 50's, there was a concerted effort to automate DAQ by building interfaces to computers that DAQ systems could be connected to. Who was first is anyones guess but DEC seem to be first with commercial buyable product. I had a 1964 DEC computer with an multi channel 12 bit ADC in it, that was a breeze to use, even with Assembler or maybe because of Assembler. The introduction of the IBM PC in 1982 saw the start of a massive increase in Computer based DAQ. Cost reduction was the main driving force. ISA bus made it possible to build excellent plug in DAQ boards and performance was very fast with DOS, with even real time performance. Windows messed everything up because it was so unpredictable in its bus and interrupt response latencies and all sorts of techniques where developed to make DAQ plug in boards run in Windows well. Real Time DAQ almost disappeared forever on PCs when Windows came along. Only realtime computers running Unix, DEC RT-11, HP RTE etc could do it, All very expensive and very rapidly becoming orphans or dinosaurs. If you wanted real time in your PC you had to have a DAQ with a micro on board and they were available. Some companies have got around this by using programmable FPGAs, NI in particular. Nice but very expensive still. Multi Cores help but still Windows is there. Around Windows XP time, Microsoft and Intel decided to close the computers up and make plug in boards a thing of the past. New busses were introduced, USB the main contender and DAQ took another turn. The reason for the closed PC idea, was support calls were often all about plug in boards issues. Most simple DAQ today is done with USB cables connecting external DAQ boxes to a PC. PCIe and PCI boards are available but most people shy away, as it requires opening the PC box up to install. If the PC or DAQ boards fail in service the technican has to open the PC and then all sorts of issues can arise. With USB, just unplug the broken PC or DAQ device and reconnect and the system is alive very quickly. So we now have a enormous range of USB DAQ models and types. Everything needed to build sophisticated DAQ systems. They are so good I personally have not used a plug in DAQ board for many years now. We have all just adapted our software around all these technology changes. DSP and DSP+DAQ combo + FPGA Techology The lead company is Sheldon. This company has been at the forefront of DSP and DSP+DAQ for 2-3 decades and even allow LabVIEW code to be run directly on the DSP boards with no OS in the way. Yes amazing. This allows building true real time DAQ and DSP/FPGA together in a PC. GPIB - IEEE-488 Products GPIB is all about T&M, ATE and DAQ. This technology allowing the connecting of programmable instruments to computers, was released in the late 60's by Hewlett Packard and originally was called HPIB. It was a giant step in technology at the time and nothing even now has surpassed it for easy of use and built for purpose, not even technologies like Virtual Instruments in VXI, PXI and LXI. In the late 80s, when virtual instrumentation was released by NI with LabVIEW, the interface method of chose for building quality Test (T&M), Automatic Test (ATE) and DAQ, was still the GPIB or IEEE-488 method for most. In 1975, when
the IEEE convened the 488th committee, HPIB became the GPIB and
the spec for it was IEEE-488. If you now read several Blogs on Building Test systems, you will find many engineers world wide, still prefer GPIB for their medium to large scale Test systems, over newer technology. The reason is it works and well and allows for very high speced instruments to be inserted into a Test system easily. Having instruments that are stand alone in their own right, allows a great deal of hands on playing and measurement method trialing with each instrument, as the tests methodiology is developed. The outcomes from this intimate playing with the instruments and Unit Under Test (UU) is then translated into commands for the instrument and embedded in the software. Very nice. Since 1975 when the IEEE-488 standard was released it has gone through many revisions and upgrades and additions. IEEE-488-1978, IEEE-488.1, IEEE-488.2, SCPI, etc with VISA added + Instrument drivers, have made the software development process so much easier and faster. For instance LabVIEW comes with hundreds of specific drivers for GPIB and other programmable instruments. The great thing
now that has developed is the melding of all Programmable instruments
into a Standardised Programmable Command Sets as a Composite
Test Instrument standard. Instruments are broken up into groups and commands for scopes from Agilent also work with Tek etc etc. This means you can swap out a scope and replace with another manufacturers scope and your test set will still work. ( As long as the instrument specs are same or similar) You can thank all those committess from 1975 onward for amassing this huge technology into an easy format. Our lead company for GPIB Interfacing is ICS of CA, with National Instruments and Adlink close behind. It seems compatibility with NI and Agilent is across all interface manufacturers. There is also
a large expanding range of GPIB development software tools, not
only for LabVIEW & Measurement Studio ( From NI ) but also
in VB, .net, C, C++, C# and most other prgramming methods + instrument
drivers in those formats also. Some LabVIEW info for this issue. LabVIEW OOPs. Here is the link, it may amaze you Next month Quick Drop |
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