Case Studies

Large Scale Distributed Data Collection Using NI LabVIEW

Posted in LabVIEW, Test & Measurement Automation

Summary

DMC developed a server based test system designed to work with several common DAQ devices such as multipurpose Yokogawa and Agilent Acquisition Devices, and Yokogawa Power Meters. The customer needed a single test system that could be used across multiple laboratories or in a ‘stand alone’ instance for a single lab. The customer also wished to standardize the test system for use across multiple facilities in the U.S. and internationally.

System Architecture

Yokogawa DA100

Yokogawa MW100

Yokogawa WT200

Yokogawa WT500

Agilent 34970

Agilent 34972A

Agilent 34980

Solution

DMC worked closely with the Client to establish the requirements for the software. It was then developed and tested while working closely with the Client's internal team of engineers.

Two applications were developed for this system which includes the primary server application and a client application. Here, the server program runs the actual tests and the client is used for test monitoring, configuring, starting and stopping the tests.

The procedure for data acquisition and test execution uses a highly parallelized architecture to maximize efficiency of the program. This allows for a high device and test count in the system. The server also has the option to operate in a 'Stand-alone' mode without clients to allow tests to run at faster sampling rates. Another key feature is that the hardware configuration can change while the application is running such that devices can easily be added and removed.

Channel configuration is also highly customizable. Depending on the device, channels can be configured for various parameters such as thermocouple type, and current/voltage ranges. Each test channel can also be set up for data monitoring by setting alarms if readings reach a specified threshold. Any particular channel or hardware configuration can also be saved for later use. There is also the capability for customizable test scheduling. A unique start time and test duration can be specified for each test that is run. Email notifications can also be enabled for delivering the test results. In addition to these channel configuration features, a tree based point and click UI was developed for easily viewing and editing large channel lists over multiple devices.

With the client application all that is needed is the server hostname or ip address to establish a connection. Once connected, a list of all active tests is displayed for viewing. Test protection is in place by binding tests to a userID for the corresponding remote client that started them. Thus, a test can only be stopped by the user who started it.

Extensive system logging was also included. A console based logger was implemented on the server with configurable levels of logging verbosity. A physical log file also exists to track test creation, start, stopping, alarms, events, and errors.

Customer Benefits

The Client gained an automated test platform to perform many of their standard tests such as measuring temperature, voltage, current, power, etc. at varying sample rates. Previously, different labs would have to manually conduct tests without a standard methodology. The Client’s test protocols such as timing, stability monitoring, and start or stop events were also integrated to the test configuration and standardized.

The Client can now run up to 1000 automated tests concurrently on a server, where each asynchronous test can be run utilizing any number of hardware devices. For conducting tests, a remote client was developed such that any PC on the network can be used for remote monitoring, starting, and stopping of tests. Data storage was centralized on the server for ease of access.

In addition to these capabilities, using a single platform across multiple labs and facilities saves on training costs for the technicians and engineers using the software.

Technologies

Devices:

Yokogawa:

  • DA100 Data Acquisition Unit
  • MW100 Data Acquisition Unit
  • WT500 Power Analyzer
  • WT200 Digital Power Meter

Agilent:

  • 34980A Multifunction Switch/Measurement Unit
  • 34970A,34972A Data Acquisition / Switch Unit

Interfaces:

  • Serial
  • GPIB
  • Ethernet

Software:

NI LabVIEW SP1

  • Device connectivity using VISA via Ethernet and GPIB
  • TDMS file storage for tests