Test Station – That need to be moved or delivered

Posted on December 4, 2008 by LV_TS_Test_Engineer_3000_VI
 
If your test station is expected  to moved around alot or is expected to be delivered consider the following:
 
  • Don’t let any equipment hang by just the front mount screw.
  • Secured  equipments with shelves or right angle support brackets to prevent movement.
  • Consider adding straps to secured  each equipment in the rack to prevent up down or side to side movement.
  • Select wheels(casters) which can  reduce vibration to Rack.
  • Some rack are fork lift to final location–Select a stronger Rack Frame.
  • Some rack are lifted via Strong EyeLoop type bolts on all top corners of the rack(Rack Frame must be made for this type handling).
  • If you have a large investment on your test station, select an air-ride trailer to reduce G shock on teststation and equipment inside.
  • Some unique part of your test station my have to be remove to ensured undamaged delivery.
  • Use Blank panel filler to help keep you test rack squared.
  • Have discussions about your shipping needs with shipping department for addition safeguard to the test station.
  • Just a reminder – Place heavier equipment lower in the station to prevent tip-over.

 

 
 
 
 
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Power Resistor- Other consideration

Posted on December 3, 2008 by LV_TS_Test_Engineer_3000_VI
Other Considerations when selecting a Power Resistor.
 
  • Temperature range of Automated Equipment
  • Location of Power Resistor affecting other subcomponents
  • Metal thickness and Surface Contact.
  • Dont Place Power Resistor where it may be touched my operators
  • Dont Place Power Resistors on area which my damage surface exposed to high temperature.
  • Consider Cooling options
  • Will Inductance affect your design.
  • Packaging of Power Resistor  

Manufacturer  of Power Resistors:   http://www.vishay.com/docs/30201/30201.pdf

Information about Resistor Selection  http://www.ohmite.com/catalog/pdf/appnotes_res_select.pdf

For distributor check  Newark  Digikey links in lists.

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Connector- Preventing hookup issues

Posted on November 22, 2008 by LV_TS_Test_Engineer_3000_VI
Connector Plug and Receptacle keying.
 
Avoid using the same Plug and Receptacle pair on the same panel or test system.
 
If for some reason you need to use the same physical dimension consider a family of connector that have keying capabilities
 
Keying can be via build-in or some part added to the connector so only the matching Plug/Rect can connect.
 
Using different physical dimension connector is also a great way to prevent connecting mishap.
ex using 9pin D connect pair and 15pin D connector pair
 
Side note
Higher end connectors may have long lead time(time from ordering to part arriving) alway ask for stock info.
Keyed connector (non default keying) my be harder to find in-stock.
 
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Automating Test solution Setting

Posted on November 19, 2008 by LV_TS_Test_Engineer_3000_VI
Understanding what setting  will be using the automated
solution will help in creating the application.
 
Lab setting –Engineers want full access to testing and see
all the parameters of the their product. (looking to prove out a design/concept).
 
Production Testing floor– Testing for pass fail with some
mode for fixing a failure. Knowing which test failed?
 
Mass production line– Very fast testing, very minimal GUI
interaction.  (GO — NOGO) testing.  ex Automotive
switch testing.(Even just a Green or Red light). Cost of product
to little to fix. Quick connect and disconnect of product.
(parameter of test still maintain for yeild purpose SPC)
 
 
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Configuration file , INI

Posted on November 18, 2008 by LV_TS_Test_Engineer_3000_VI
A popular configuration file format used for the automated software to  setup, initialize, configuration it parameters
 
Section, key , Value
 
[Section Name1]
Key1=Value
Key2=Value
[Section Name2]
Key1=Value
Key2=Value
Key3=Value
[Section Name3]
Key1=Value
 
LabVIEW has a tool section to handle many action required with Section,Key,Value format INI files
Both reading and writing.
 
LabVIEW is a product of National Instruments.
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Temperature – Thermocouple,RTD and Thermistor

Posted on November 17, 2008 by LV_TS_Test_Engineer_3000_VI
Need to Measure Temperature?
 
Learn about different ways to measure temperature using Thermocouple,RTD and Thermistor.
 
IOTECH has and excellent discussion on these components for measuring temperature, check out the following web site:
 
 
IOTech website : www.iotech.com
 
 
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Interface Test Adapter

Posted on November 16, 2008 by LV_TS_Test_Engineer_3000_VI
Do you have to test many different UUT Cards which use similar Test equipment to perform the test in a production area?
 
Consider a Common TestStation with a receiver panel routing to the various equipment required in the station.
 
Then create ITA adapters for your various cards that have support component and wiring to Interface panel which mates with receiver panel.
 
Consideration
Dont make your ITA to heavy if you expect one person to remove and install the ITA.
 
Alignment is critical to the life of the contact on the Receiver Panel and the ITA.
 
Dont think that your can not have support electronic in the ITA ,support electronic my improve reliablilty to your test setup.
(example if your board(s) needs 10Mhz just as a base clock think about adding the clock circuit in the ITA instead of having it travel long distance thru the Receiver Panel)
(sometimes thinking "inside the box(ITA)" is the right thing to do.)
There are so many USB device that can fit inside the ITA  to do some small function and have a feedThru on the ITA or as an external connection with common USB cable.
 
Switching Matrix are common in Common or Base Test Station to provide unique routes required for you product.
 
Please read the spec on Swithing Matrix to exceed  requirement of the signal(s) to be testing from each receiver panel connector.
 
Safety:   Consider that your Receiver Panel  many need to disable the Signal going out of the Receiver Panel(Interlock).
 
If you have many boards and expect many ITA you will need a storage area.
 
Protect the ITA with some form of Cover to protect Interface pins, also  protect the Receiver panel.
 
Also dont forget to get the insertion and remove tools.
 
In conclusion, review you project’s requirements for the various boards and see if a common Test Station is required.
Review cost and product testing flow rate required by production to product the final Unit of company to see if you need more then one common Test Station.
 
 
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Real Time Computer

Posted on November 14, 2008 by LV_TS_Test_Engineer_3000_VI
RT Computer typically will have
   Time Critical Loop(deterministic response)
   Non Critical loop (Monitoring info to and from the  Host Gui)
Recommendations(to reduce Jitter)
Minimize the use of interrupts(COM Port type cards are interrupt driven devices), Disable Dedugging tools on on RT LV vi,,Disable Com is not used.
Use FIFO for Time Critical and Host Comm loop communication.
Use Fix Size Array. NO build array type function in time critical or Host loop.
LV Shared Variable
Provides a means
to have access to
variable access the
network between the Host and the RT.
The LabVIEW project makes it easy to created the SharedVariables
(Minimize the number of SharedVarible  from and to the RT and Host to reduce Enet traffic)
Provide a way to verify Deterministic quality(jitter) at a minimum use the parameter from the TimeCritcal TimedLoop structure.
Related Software Development Tools
LabVIEW(r)
LabVIEW RealTime
 
 
 
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EMC – Radiated Susceptibility Testing

Posted on November 13, 2008 by LV_TS_Test_Engineer_3000_VI
Equipment
 Signal Generator
 Amplifiers
 Antennas
 Power Meter
 Attenuator as need
To Automate
 Controller
 Development Program
 Equipment must be programmable.
 Specification for Frequency and Power Level
Signal Generator (basic function)
  Set Output ON/OFF
  Set dB level
  Set Frequency
Amplifier (basic function)
 Set Enable/Disable output
 Get Status –Check for overload (from Drive or Reflection)
 Get Output power level
 Reset Overload
Power Meter (basic function)
Set Range
Get Power Level
Power Meter used to verify Power Level reached at selected Frequency
UUT
Monitor no anomaly during Testing (Frequency Range and Power)
Both Measured Telemetry/Physical Changes
Equipment Note :
Amplifiers can be damaged with excess input power
Bad Cabling can result in excess reflected power
During Testing: NO Body inside Shielded Structure.
Caution Radiated Susceptibility Testing involves very high Frequencies with power levels.
Testing is done inside an enclosed shielded Structure to prevent energy from entering or exiting structure.
Before entering the Enclosed Shielded Structure, MAKE SURE the Signal Generator is disabled with highest attenuation (=lowest gain) (or better yet Powered OFF), Amplifiers Disable, Power Meter indicates no Power.
Refer to many other sites and books to learn more about Radiated Susceptibility
 
 
 
 
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NI FPGA (Reconfigurable Input Output)RIO

Posted on November 11, 2008 by LV_TS_Test_Engineer_3000_VI
Need to create hardware and you know the customer requirement my change then consider (NI FPGA solutions)
 
If you know LabVIEW already you can be programming NI FPGA quickly with the LabVIEW FPGA module
 
What great is that the FPGA shows up in your LabVIEW Project lvprj  so you can see all your IO(Analog input,output Digital output).
 
All Vi related to the FPGA will show it a the target in the lower left corner of the VI(block or diagram)
 
NI also refers to the FPGA as RIO.
 
Once you have completed the FPGA code that you created  just compiled to created  a required Bit file to be download to your new NI-FPGA configuration.
 
This Bit file reference will allow the NI-FPGA load and provide a reference that you Host application can access node you provide (input and output you created in the FPGA VI code.
 
A note so you know ahead of time, in order to layout the NI-FPGA the program will go into and compile-optimize routine which can take many min(45 to 1hr) depending on the amount of code in the NI-FPGA VI. It still better then making a new PCB, or waitng for the FPGA department to address your request for change.
 
Reconfigurable IO just where you need it making your automated solution reconfigurable . YES!!!
Counter
PID loop
Event Counter
Pulse gen
Hold/Track
Rate Control aquistion
FIFO and Memory for larger data handling
Special TX RX protocol
Too many possibility….
 
Below are some configuration with FPGA (their are many other configuration)
 
 
Additional information my be obtain at
 
LabVIEW and TestStand are products of National Instruments
 
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