test&measurementZONE Products for the week of October 1, 2007
Data Translation Says…
TEMPpoint Ultra-Accurate Thermocouple Measurement Instrument
Data Translation, a leading solution provider for data acquisition test and measurement, announced TEMPpoint--an easy to use series of high accuracy temperature measurement instruments. Each TEMPpoint instrument is a stand-alone box offering 48 separate 24-bit resolution inputs, each with its own A/D converter and CJC, as well as a USB or Ethernet port for connecting to a PC.
"All aspects of each separate measurement, embodied through features not available in any other instrument, are handled automatically within the stand-alone box," states Fred Molinari, President and CEO, Data Translation Inc. "Care was taken in the design of TEMPpoint to protect signal integrity of all 48 channels in even the harshest environments."
- Key Design Features of TEMPpoint Offering Unmatched Accuracy:
- 48 dedicated 24-bit A/D converters for ultimate resolution
- 48 dedicated CJC circuits guarantee ultra-high (+/-0.01%) accuracy.
- 1000V Channel-to-Channel galvanic isolation for superior signal protection
- Anytime auto-calibration guarantees accuracy
- Automatic linearization of B, E, J, K, N, R, S, and T standard thermocouples
- Expand to hundreds of channels by adding boxes to the network
Additional Features of TEMPpoint include:
- Constant throughput across all channels at rates up to 15-Hz per channel
- Thermocouple Easy Connect for fast setup
- 8 opto-isolated digital input lines for monitoring
- 8 opto-isolated digital output lines for driving relays
Software Support for TEMPpoint
TEMPpoint ships with a ready to measure comprehensive TEMPpoint application. The TEMPpoint application is an executable program created with Measure Foundry. The benefit for the user is that the application can be modified or expanded to meet a particular need. The TEMPpoint application allows you to acquire temperature measurements from up to 48 thermocouple or RTD channels, display, analyze, and save data to disk, all without writing any code. Additionally, the TEMPpoint application offers the ability to export data to other applications such as Microsoft Excel and MATLAB. Additional information on other USB and LXI software supporting TEMPpoint including IVI-COM drivers, .NET class libraries, and SDKs is available at http://www.datatranslation.com/temppoint/
En-Genius Says…
This is a rather nifty design, both electrically and mechanically. Although briefly mentioned in Data Translation's press release (above), it's worth emphasizing that individual delta-sigma auto-zeroing ADCs are used for the TEMPpoint's separate 24-bit inputs.
 The use of these high-resolution ADCs ensures that each dedicated conversion channel can operate at its highest possible resolution (in this case it’s one part in 16 million). There's no MUXing or sharing of these inputs, and a voltage input can be fed in, or a thermocouple can be attached, to any channel at will. Any channel can read within ±0.1°C. Each ADC also ensures anti-aliasing filtering that tends to reject 60-Hz (and 50-Hz) noise.
In terms of practicality, these high-resolution 24-bit channels pay dividends. Front-ends that use lower resolution ADCs usually need op amps or instrumentation amplifiers ahead of the data converter chips. Depending on the quality of these amplifiers, they can limit accurate measurement. Errors with Data Translation's 24-bit converters are far smaller than with 16-bit converters-plus-amplifiers, for example. Very small voltages, such as those generated by industrial thermocouples, can be readily digitized with accuracy. What's more, drift errors from analog op amp conditioning circuits are eliminated.
Dedicated Compensation
Data Translation's design provides dedicated cold-junction compensation for each thermocouple input as well. And, all channels are totally isolated form each other, the chassis, and your host PC. Channel-to-channel isolation is rated at 1 kV, and every one of the system's optically-isolated 48 inputs include jacks that support rapid plug-in connection of external sensor wiring. These connections even monitor for open or faulty connections.
The TEMPpoint box also warms up and stabilizes rapidly. In fact, Data Translation guarantees you'll be able to use it, and attain full accuracy, after no more than nine minutes following initialization. That goes hand-in-glove with the system's ability to run almost as a plug-and-play instrument, with no software coding required. Just run the supplied TEMPpoint application, an executable that can be modified and extended using Data Translation's existing Measure Foundry software. Using the TEMPpoint application, the system's thermocouple types and channels are displayed, letting you analyze the results in real time on your PC's screen.
They’re LXI-compliant
I think Data Translation underemphasizes that you can order one of these systems with LXI (LAN eXtensions for Instrumentation) hooks, and/or USB (Universal Serial Bus). There aren’t that many instruments available supporting Ethernet LXI these days; kudos to Data Translation for bringing out plug-and-play LXI-compatible slow-speed industrial data-acq systems. Thanks to LXI and a Web connection, you can also configure, measure, and control one or more of these 2U-sized boxes locally or remotely.
What's more, the LXI hooks support e-mail notification. This lets you run a system unattended. If a measurement exceeds a pre-set limit, an e-mail notification is automatically generated and sent.
Programming and Operational Versatility
It should be relatively easy to get one of these systems up-and-running. For both USB and LXI versions, Data Translation supplies an IVI-COM driver that lets you write application programs for TEMPpoint using an IVI-COM instrument interface. This can be used with programs written in Visual C# or Visual Basic for .NET under Visual Studio 2003 or Visual Studio 2005. You can also use the IVI-COM driver with the ever-popular National Instruments LabVIEW graphical programming “language.”
Data Translation's software also supports Web pages for configuring networking connections, input channels, and parameters such as scan rates, alarm limits, and digital I/O lines. Similarly, control Web pages can be used to start or stop a scan, or to update the value of a digital output port.
Speaking of digital I/O, the TEMPpoint hardware accommodates digital input levels anywhere from 3 V to 28 Vdc. The digital output lines, with 250 V of isolation line-to-line, are fast solid-state relays that can heft up to ±30 V and 400 mA apiece. I/O is connected via a 37-pin subminiature D-type connector on the TEMpoint’s rear panel.
Web operations can be used to view temperature results in either bar graph, panel meter, or strip chart-like displays. You can also look at the value of a digital input port. As you'd expect, you can also download your measurements across the Web, and save them to your local PC storage. When saving these disk files, the system time stamps all scans and saves the measured limits of each as well.
USB-only Boxes
If Web operation isn't your cup of tea, you can choose a TEMPpoint system for USB-only. These configurations are supplied with the company's DT-Open Layers for .NET Class Library. It's a collection of classes, methods, properties, and events that provides a programming interface for Data Translation's DT-Open Layers-compatible hardware devices. In use, DT-Open Layers can be in any language that conforms to CLS (the Common Language Specification), including Visual Basic.NET, Visual C#, Visual C++.NET (with managed extensions), and Visual J#.NET.
If you're not up for crafting your own apps, Data Translation supplies an executable called quickDAQ for TEMPpoint. It lets you acquire, plot, analyze, and save temperature data, add markers, min/max points, and alarms. You can also use quickDAQ to export datasets to other applications such as the company's Measure Foundry, or Excel spreadsheets, or the popular MathWorks MATLAB analysis program. A DAQ Adaptor component for MATLAB provides the interface between MATLAB's data acquisition subsystem and the DTOpen Layers architecture.
Data Translation also supplies a Windows SDK (software development kit) for its USB boxes. The Win32 SDK comprises header files, libraries, example programs, and documentation so you can develop your own DT-Open Layers data-acq and control applications. The SDK is for use with non-.NET languages, such as C, Visual C++ 6.0, and Visual Basic 6.0.
Finally, USB TEMPpoint implementers get a VB.NET example application, replete with source code. This sample program is a temperature measurement application written in Visual Basic.NET and the DT-Open Layers for .NET Class Library. It lets you configure a TEMPpoint instrument, log data to disk for analysis, display data on-screen, and monitor and control the box's I/O lines.
Pricing starts at $6,995 with four separate versions: thermocouple inputs for USB; RTD inputs for USB; thermocouple inputs for Ethernet (LXI); RTD inputs for Ethernet (LXI). The Thermocouple USB version will be the first to ship, in early October 2007.
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