Electric Motor Test Bench

[MwMonty]

I am currently desiging a small AC Motor Test Bench to test motors on the production line. I am trying to decide the best way to detect a break in the light curtain. A beak in the light curtain will be removing all line voltages from the bench top and will also reset the vi to await a start signal from an operator push button. I have a NI cDAQ 9178 with a NI 9205 and six NI 9481 modules.

I do have a extra relay contact in my safety circuit that I can pass a 0-10V signal through to the 9205. I am considering using a 120VAC to 9VDC transformer to generate a control voltage. I would then use the control voltage as an input into the 9205. I could wire my start button, safety relay and stop button in series. The safety signal would be normally closed and the stop and start would be normally open. I do not need this to be real fast detection by the circuit but would like it to be under 1 second.

Is this the right approach?

How should I write this into my vi to detect an input even is a sub-vi is running?

[DianeS]

So, a question:

Are you performing any other acquisitions with your 9205?  If so, are they hardware-timed?  I believe the 9205 has a single clock (I might be wrong about that, you'll have to check), which means that you can only run a single hardware-timed task with it.  This may not be relevant, but it's something to note.

Since the detection doesn't have to be very fast, you could set up a software-timed task to read the line which has your "stop" signal.  (That avoids any sample clock conflicts.)  You'll want that task in its own loop, in parallel with the rest of your code, so that it runs all the time.

When you detect a "stop" signal, you'll need to take action in the other software loop(s).  I'd use an Action Engine (search the forum if you're not familiar with it) to set a flag which is read by the other loop(s).  Use the flag to trigger whatever shutdown actions are necessary.  Your "stop" monitor loop will write to the Action Engine -- your other loop(s) will read from it.

Does that help get you started?

[MwMonty]

Yes, that is a big help, I will have to read up on action engines.

I will be taking some other readings off the 9205, but they do not require clocks or triggers. They will be a step in the main series of steps the VI completes.

[DianeS]

To (I hope) save you some heartache later, may I recommend you do some research on code architectures as well?  I'd like to steer you towards a state machine for your main code if you aren't thinking that way already.  I don't know how much LabVIEW experience you have, so forgive me if you already know about architectures, best practices, etc.  A lot of newer users have an unhealthy fascination with sequence structures and there are much more powerful, flexible, efficient ways to do things...such as a state machine. 

Just trying to start you down the right path to begin with...

[MwMonty]

I am using a state machine architecture. I am a newbie at LabView and just took Core I & II last month, so any advice is appreiciated at this point. I'm currently just trying to make sure I have a good handle on making sure that my external inputs will be detected by the VI.

[DianeS]

I'm glad to hear that you are using a state machine and that you've taken some classes.  It sounds like you've got a good handle on where to start.  My best advice at this point is to write out some psuedo-code so that you have everything mapped out and your process laid out, then start coding it up.  Think in terms of modularity (you undoubtedly already know that).  If you get totally stuck, post with a specific question and we'll do our best to help! 

For myself -- and this is just general advice -- I find that, when I'm trying to understand a concept or how a function works, I learn best by scribbling up a small VI that focuses solely on what I'm trying to understand.  Breaking things down that way, focusing on one concept instead of trying to learn something while integrating it with something else (that I may or may not truly understand), enables me to learn a lot faster.

The help files and example code which ships with LabVIEW are terrific resources as well.

Have fun!

[globalvision]

Hi all , 

Good day 

i am planning to buy  a electric motor test bench with below requirement , i would highly appreciate if anyone can suggest the best brand who does it .

BENCH, MOTOR TEST
TEST BENCH FOR TESTING MOTORS:
For testing electrical motors of the
alternating current with frequency of
50 Hz with short circuited and phase
rotor of the capacity upto 120 KW.
FEATURES:
- Measuring winding isolation resistance
in relation to machine
body and between the windings.
- Measuring winding resistance under
direct current.
- Determining transformation ratio of
phase rotor motors.
- Electrical strength trails of winding
isolation between loops.
- Determining of idle current.
- Determining of short circuit and
losses.
- Supply voltage: 440 V.
- Operating current: 500A.
- Following 3 testing positions on the
Test Bench:
a) Upto 15 KW
b)15t060KW
c) 60 to 120 KW
GENERAL REQUIREMENTS:-
I) Equipment should be latest version
available.
2) ALONG WITH QUOTATION:
a)Catalogues & Technical
Specifications ( including optional
extras) of the offered Model to be
submitted with the quotation.
b) Prices for all optional extras to
be quoted separately.
( not to be included
in the overall bid price).
c) Details and prices of consumablesl
spares required for 2 years operation to
be provided.
d)All documentation to be in English.
3) WARRANTY:-
Equipment to have full warranty for
a minimum period of one year from
receipt in KOC Stores.
4) AFTER ORDER PLACEMENT
a» Equipment shall be supplied to KOC
Stores complete with permanent
identification tags stating Model no.,
Serial no. and Manufacturer details.
b) Equipment shall supplied with
Operation & Maintenance manuals,
Calibration Certificates and complete
Spare Parts List.
TYPE : MOTOR TEST

anticipating a quick reply .

regards 

Sairam 

[nikale]

Hi globalvision,

Your post will likely get more attention by creating a new thread. Generally it is not recommended to post on old threads. Also, if you're looking for a quote or advice I would recommending contacting NI https://www.ni.com/contact-us/.

I hope this helps!

- Kale