Pickering Interfaces, a market innovator in signal
switching and conditioning in association with
Captronic Systems one of the leading Automation
and Test equipment Specialists, cordially invite
you
for a Seminar on,
“NEXT GENERATION SWITCHING SYSTEMS”
Covering latest Switching Technologies and
Platforms offered by Pickering Interfaces and usage
of these system in solutions implemented by Captronic Systems for the Automotive, Aerospace &
Defence and Manufacturing companies.
It will also cover the world's highest density
switching matrix (the BRIC modules), RF
and optical
switching products,
It will address application of switches in HILS, Fault
Insertion, and Automated Test Equipment
The Solution:
Utilize the flexibility & ruggedness of NI Compact fieldpoint modules and the graphical features of LabVIEW to build a configurable, expandable functional test bench which will minimize testing time and maximize productivity.
Introduction:
Cluster assembly in an automobile includes the speedometer, tachometer, fuel gauge, temperature gauge, odometer and a set of telltale lamps. Conventional clusters have mechanical parts which in addition to being cumbersome will give erroneous results. In contrast electronic clusters have less weight, longer life and gives more accurate results. The test system to be developed was for the end-of- line functional testing of electronic clusters. The main requirements for the test setup were
- Voltage as well as current measurement capabilities
- Ability to turn ON and turn OFF sinking & sourcing LEDs
- Ability to drive electromechanical relays
- Ability to generate square wave of variable frequency
- Compactness, Ruggedness and reliability
- Provisions for future expansion
- Ability to store test data into a database
- Generation of reports from test data
- Simulation of test sequence in software.
National Instrument’s Compact FieldPoint (cFP) distributed I/O system supported all the above functionalities. Analog Input cFP modules were used to measure both voltage and current, sinking and sourcing DO modules were used to activate LEDs and to drive relays. Since required frequency resolution was high NI Basic DAQ card was used to generate square waves. Also the modularity of FieldPoint modules allowed scope for future expansion. The test software was developed using LabVIEW 7.0 whose excellent graphical capabilities came handy while creating user interface and doing test simulation. Database connectivity toolkit for LabVIEW was used to log the test data and to store test configuration to an MS Access database.
Application:
In the end- of –line functional testing of electronic clusters, various conditions like speed, engine RPM, fuel tank level etc. were simulated through hardware and were applied to the respective pins of the cluster and its behavior to these inputs were noted. The speedometer & tachometer required frequency inputs while the fuel and temperature gauge required resistance inputs. The tests include sweeping of speedometer and tachometer from minimum to maximum and back, applying square waves of frequencies equivalent to known speed and RPM and testing whether indicated values in speedometer and tachometer are within acceptable limits or not, checking of fuel gauge and temperature gauge indications by applying corresponding resistance inputs, measurement of telltale lamp currents and switching of f telltale lamps to check for light leakage.
There were a total of 22 telltale lamps, one speedometer, one tachometer, one temperature gauge and one fuel gauge. There were five cluster variants and the number of telltale lamps present was different for each variant. Also the maximum range of speedometer and tachometer also varied depending on cluster selected.
During the test, the cluster assembly had to be held stationary by a set of pneumatically actuated clamps. Also the entire test hardware including power supplies and pneumatics were to be mounted in a suitable rack.
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