Projects
Case Study - Creep Testing Laboratories
Products
LabVIEW | CompactDAQ | VISA
The Challenge
To replace an aged control program written in GW-BASIC for high temperature creep testing laboratories with a robust system using a stable, flexible, rig-oriented LabVIEW data logger, CompactDAQ and high temperature thermocouples.
The Solution:
Using National Instruments LabVIEW and the reliable, robust VISA drivers, a modern driver was developed for the legacy hardware within hours.“Using LabVIEW in combination with DAQmx and the VISA driver, allowed for development of a flexible, robust control system with potential for future expansion, remote working, network and internet capabilities.”
Introduction
A system was in place from the early 1980’s to measure displacement of materials using various micrometers when a load is applied over various time periods. A system refresh was required to add in the ability to log temperature data, increase the test memory capabilities and make the test rig look more modern and professional for when visiting clients were inspecting the test procedure.
Test System Instrumentation
Using NI-VISA and LabVIEW, a reliable driver was developed for the aged ASL displacement measuring hardware. This hardware can sample up to twenty-four channels of displacement, balance strain bridges, format and return the result in micrometers.
The latest versions of DAQmx under LabVIEW 8.5 were used to read two thermocouple channels from each creep testing rig.Software Development and Integration
The software, developed using LabVIEW, was a distributed, Windows-service oriented data server and dynamic client launcher. This innovative system allows the client, server and launcher to be developed in isolation. New versions of the client are developed and can be 'dropped into' the system directory without having to recompile the entire system.
The software provides a clean, modern user experience, whilst "under the hood" it is based on robust, reliable TCP/IP. This flexible architecture means that the system could be run remotely, with client programs communicating across the LAN or internet to the data server.Cost Savings
Utilising existing displacement transducers and conversion hardware led to cost savings within the project. The Compact DAQ chassis, which is currently being used for temperature measurements, could be re-used with different modules to add future functionality to the system with minimal expenditure.
In addition, the LabVIEW deployment can easily be deployed to future laboratories, and is a flexible platform for 'plugging in' different transducer types with minimal new coding effort.
Additional Benefits
Fresh, modern Graphical User Interface (GUI):
- LabVIEW modern controls and indicators give the new clients a professional look and feel
- Visiting clients are impressed by the various test indicators which are displayed on a quality, high-end user interface
- During development, new versions of the client VI could be e-mailed to the client, dropped into the working directory and utilized immediately, without having to reboot the system or restart the server.
Example Rig Selector Application – (Rigs 1 and 4 are currently running)
Pressing the central buttons starts tests if they are not running, and calls Client Front Panel up if they are already running. The light green indicators indicate running tests.
