Pressure, Load, and Torque Measurements Made Smarter and Easier

Publish Date: Mar 08, 2016 | 4 Ratings | 3.25 out of 5 | Print | 1 Customer Review | Submit your review

Overview

If you ever thought using a sensor should be as easy and trouble free as plugging a mouse into your computer, then the IEEE 1451.4 standard for transducer electronic data sheet (TEDS) may be your answer for self-describing, plug and play sensors. When you set up and configure a traditional DAQ system, you must manually enter important sensor parameters, such as the range, sensitivity, and scale factors, in order for the software to properly use and scale the sensor data. However, A system outfitted with IEEE 1451.4 sensors and actuators can automate this configurations step, while also increasing the general integrity and reliability of the system.

Table of Contents

  1. How are these Sensors Smarter and Easier?
  2. How Does TEDS Work with Hardware and Software
  3. Embedded, USB, Ethernet or Wireless System Deployment
  4. Flexible Solutions for Test
  5. Next Steps

National Instruments provides load cell, pressure sensor, and torque sensors from Honeywell, a leading sensor provider, to enable an easier and smarter sensor measurement experience. Test systems combining these sensors with NI instrumentation will offer several benefits, including quick connectivity, onboard sensor information through TEDS technology, and several bus communication options.

1. How are these Sensors Smarter and Easier?

Setting up a Wheatstone bridge-based transducer, such as a load cell, pressure, or torque sensor, requires several inputs from the sensor data sheet. These inputs, such as sensitivity and gage resistance, allow the instrumentation and software to properly convert the output voltage from the sensor into engineering units.

All load cell, pressure, and torque sensors from National Instruments come with a pre-installed TEDS memory chip. The TEDS chip stores the important setup information from the data sheet using an IEEE standardized template, described more in the IEEE 1451.4 Sensor Templates Overview Whitepaper. With the setup information on the sensors, TEDS-compatible instrumentation can communicate directly with the sensor and perform the setup programmatically. Therefore, TEDS-compatible software can automatically scale from polynomial functions provided by the sensor manufacturer or other calibration lab.

Basic TEDS Manufacturer ID 21
Model ID 19
Version Letter D
Serial Number 8451

Standard and Extended TEDS 

(fields will vary according to transducer type)

Calibration Date 10-Feb-14
Measurement Range ±100 lbs.
Electrical Output ±3 mV/V
Bridge Impedance 350 Ω
Excitation, nominal 10 VDC
Excitation, minimum 7 VDC
Excitation, maximum 18 VDC
Response Time 333.33μs
User Area Sensor Location R32-1
Cal. Record ID 543-0123

Figure 1. Example TEDS for A Load Cell

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2. How Does TEDS Work with Hardware and Software

The IEEE 1451.4 standard defines two types of mixed-mode interfaces, designated as Class 1 two-wire and Class 2 multi-wire interfaces. The load cell, pressure, and torque sensors from National Instruments are Class 2 multi-wire interfaces. The Class 2 interface uses a separate connection for the analog and digital portions of the mixed-mode interface. The analog input/output of the sensors is left unmodified, and the digital TEDS circuit is added in parallel. This enables the implementation of plug and play sensors. The figure below illustrates the implementation of a Class 2 mixed-mode interface.

Figure 2. Class 2 Multi-Wire Interface

Hardware

National Instruments data acquisition implements the IEEE 1451.4 Class 2 multi-wire interface to read the digital TEDS information, as shown in Figure 2. There are several connector options available with the load cell, pressure, and torque sensors that you can use to connect directly to one of the National Instruments’ input modules: NI PXIe-4330, NI PXIe-4331, NI 9237 and NI 9219 (pressure and torque only). This will enable an easy, out-of-the-box experience that requires only a screwdriver for pigtail connections and no tools for RJ50 connections. The NI PXIe-4330, NI PXIe-4331, and NI 9219 modules use screw terminals for pigtail connections, while the NI 9237 module uses RJ50 connectors to quickly connect a load cell, pressure, or torque sensor to the module.

Software

NI TEDS software compatibility is in the driver layer, which means that you can set up a TEDS sensor with or without a full test software application. This is useful for taking quick measurements through a test panel or for debugging installed test systems. The driver support for TEDS also means that you can program for TEDS with several programming languages, including NI LABVIEW graphical system design software, LabWindowsTM/CVI, Microsoft Visual Studio, C, C++, C#, and .NET.

Watch how it all works together!

Video: TEDS technology stores setup information with the sensor.

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3. Embedded, USB, Ethernet or Wireless System Deployment

The NI PXIe-4330 and the NI PXIe-4331 are bridge-based measurement modules which are part of the SC Express family of hardware and have an embedded option for system deployment. The NI PXIe chassis and PXIe controller support up to 17 modules and have a built-in processor, memory, and storage space designed to run a LabVIEW program locally. Due to the modularity and flexibility of this hardware system, you can use this system for just a few measurements up to thousands of measurements.

The NI 9219 universal analog input module and NI 9237 bridge-based measurement module are part of the C-series family of hardware, and as such have several options for system deployment. Single-module carriers are available for USB, Ethernet and wireless communication back to a PC. With four channels per module, the single-module carriers are ideal for lower-channel-count systems that need to be small and portable. For larger systems, NI CompactDAQ offers USB, Ethernet, and standalone chassis that support the NI 9219 and NI 9237 modules. You can use the four- and eight-slot NI CompactDAQ chassis to install multiple NI 9219 and NI 9237 modules, creating higher-channel-count load, pressure and torque systems.

 

Both platforms are capable of creating mixed-sensor test systems that can measure voltage, current, temperature, sound, vibration, power, and digital signals. With these modular, flexible hardware systems, you can deploy load cell, pressure, and torque sensors in a wide variety of applications.

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4. Flexible Solutions for Test

National Instruments sensing portfolio includes load cells, pressure and torque sensors, all of which come in a variety of form factors for just about any application you need. These applications require sensors ranging from those for general test and measurement to ones that must meet harsh and demanding conditions. A system that incorporates these TEDS enabled load cells, pressure and torque sensors with NI instrumentation is more flexible, and much quicker and easier to setup.

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5. Next Steps

Learn more about TEDS

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Customer Reviews
1 Review | Submit your review

A complete work  - Jun 15, 2010

A complete work, a universal application, clearly presented and ready to test.

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