TV measurement related help needed

[guogang]

Hi,all

I am a new guy for NI-labview,and now i have a project to do with labview.For TV-product test,i want to measure some items by PC control,the list is below

Gain Limited Sensitivity

Noise - Limited Sensitivity

Selectivity HF + IF

(S+N)/N - ratio

SCART output voltage

Video amplitude frequency response

Group delay frequency response

Sound carrier suppression

2T-pulse / bar rating

2T-pulse response

Field frequency squarewave response

Non-linearity of the luminance signal

Line tilt

Differential gain

Differential phase

Chroma and sound intermodulation level

and now the equipment we used is R/S saf(cvbs generator),sfm(multistand modulator),vm700(video analyzer).

Does anyone can help me for setting up this project or give me some ideas.

[Mike Ashe]

Where to start?

Hmm, I'd start by forgetting about LabVIEW for a short while and use your two most important tools, a pencil and pad of paper to sketch out each of the basic tests you list above, with TV (Units Under Test) and the specific test equipment for each, what the signal settings need to be, the expected TV response, etc. Figure out what you need to do, not how. Do this for each test.

Then list the equipment you have available for each test (or are you still picking out equipment?) and the communications method/bus for each (PCI card, PXI, GPIB, Serial, etc).

Then look in the \examples directory in LabVIEW for tips on how to talk to each of these (GPIB, serial...). Follow this by searching for example(s) on test executive. Then look up LabVIEW on Amazon.com where you will find many good books. I would suggested "LabVIEW for Everyone" by Jeffrey Travis (third edition will be coming out soon so you may want to wait a while) followed by the top 6 or so books on the Amazon list.

Somewhere along this path of enlightenment you should search LAVA for "test Executive" and while you are at it NI's DevZone as well.

Once you have done all this you should be well on your way to solving this test problem. If you want to take a shortcut from the above I (and I'm sure several others on this forum) would be happy to quote you help on a paid basis. But beyond that, lets be frank, your question is, how do I say this, a bit broad and asking this type of question on your first post sounds like you are asking us to do your homework for you.

Now if you have been dropped into this situation by your employer, if they said, "here is the TV assignment, use LabVIEW, get going, we expect you to be done by next Tuesday...", and you are really new to LabVIEW, well then I can sympathize. NEVERTHELESS, your question, as stated, is more properly suited as an initial question to a local NI Alliance member when you ask them to quote doing the work for you, (or providing "Startup Assistance") not to an advanced (well, it says so in the forum name ;-) ) forum where people volunteer their time and typically answer much more specific questions.

Good luck, but you probably shouldn't expect a lot more help until you have narrowed your question a bit and learned a bit more about LabVIEW in general, rather than specific to TV testing.

(For Michael Aivaliotis and others: my coffee tastes especially good this morning, so I was feel gentle and generous. Now where was that post on how not to ask your first question ... )

[Irene_he]

Where to start?

my coffee tastes especially good this morning, so I was feel gentle and generous. Now where was that post on how not to ask your first question ... )

I guess I understand how you feel... well, I like the statement "Don't ask me to do your homework". This would be the final answer to rescue some headaches for being nice.

Irene

[Irene_he]

Actually I felt not very good for my above reply, that's why I have to reply again here it maybe some of my headaches drive me into narrow thoughts, although I haven't really replied to anybody yet with "Don't ask me to do your homework", I always tried to answer... The "Don't..." answer apparently is not the correct answer to any questions...

Generous people are always a look up model and respectful person for me.

Sorry for haveing answered the question with "Don't...", it's worse than not answering

Irene

[crelf]

Actually I felt not very good for my above reply...

Hi Irene,

I wouldn't worry to much about you reply - we all get frustrated when we think that someone is trying to take advantage of us, and I agree with Jim's earlier comments about posting your homework on a professional forum seeking answers to the complete system from professionals is akin to cheating. As has already been said, if the student takes the time to try to understand the question, and at least makes an attempt at it (and demonstrates that), then no worries, but cut-and-paste a whole class assignment? That's asking for wrath

PS: I think Micheal's post :thumbup: is in excess of what the original poster could expect (although it'd be nice if they came back with at leat a thankyou... :thumbdown: )

[Louis Manfredi]

I agree with Jim's earlier comments about posting your homework on a professional forum seeking answers to the complete system from professionals is akin to cheating. As has already been said, if the student takes the time to try to understand the question, and at least makes an attempt at it (and demonstrates that), then no worries, but cut-and-paste a whole class assignment? That's asking for wrath

... Not akin to cheating, it is cheating. To my mind, the more serious aspect of the problem is not that this activity wastes our time in the forum-- it is that we're going to have to work with these slobs (that is to say, we're going to have to carry their load for them) when they are let out into the workplace with essentially meaningless credentials.

...Perhaps if the professors assigning these problems knew about LAVA and checked in on the traffic when assignments were due the whole problem would go away-- they could decide how much help was too much & deal with it much more effectively than we can.

... There was a software manager at a company where I used to work who would give all interviewees a computer and ask then to write a bubble-sort program from scratch in a language of their choice before the interview proper began. I used to think that he was being a bit of a jerk to put the candidates on the spot, but as I approach old-farthood I begin to think it wasn't such a bad idea.

Ah well, just a morning rant, :ninja: Perhaps I should brew a nice pot of cafiene to try and calm my nerves.

Best, Louis

[crelf]

There was a software manager at a company where I used to work who would give all interviewees a computer and ask then to write a bubble-sort program from scratch in a language of their choice before the interview proper began.

At the last company I worked at, I did exactly the same thing - I had a standard two-part task that all candidates had to attempt within a time limit on a standard install PC at our office (I had them attempt the task after the interview). It really really helped - anyone can fake a resume, most people can fake an interview, but good ol' Linus is our savior once again: "Talk is cheap, show me the code". It was sobering to find that around 75% of the people that I interviewed who were self-proclaimed LabVIEW genius' weren't able to find anything they needed on the palette, let alone wire them together I always said to candidates: if you need help finding components, or don't quite follow the task, then please ask me - you'd be surprised how many didn't and turned in a couple of VIs with almost nothing in them (and then expected a job )

[Irene_he]

Thank you Christopher and others and this forum, you all not only give great LabVIEW help, but also provide some very thinkable opinions on life attitude.

Thank you.

Irene