tdms file break down in parts

[cees10]

How do you break down a tdms file   down in chunks  of a certain  value

I have a file that  come from counter ,evry let say   20 counter value's respresent   1 turn

Now i want to have the whole file    in   turns     so evry 20 counter values     then compare them and see  how in  changes  .

This change  tells be a certain behavoir of a problem ( imbalance)

Now the the absolute values does not say evry thing since its not a constant speed   the speed is  slowly going down

I if  i see it like a wave form  and all  rotation on top of each other   like a waterfall plot.

But i have no idea how the cut this file in even parts    ,and make a waterfall plot

Some have a good idea how to do this?

Cees 

[Brad_Turpin]

Hi Cees,

It sounds like the first thing you want to do is convert your counter channel into a Cycles channel.  Then are you saying you want to break the data from each wheel revolution into its own channel so that you can display a waterfall graph?  You can create the waterfall graph in DIAdem without breaking out the data into separate channels once you have the Cycles channel.  A waterfall graph has 3 axes, what do you want on the 3rd axis?  So far we've got amplitude on the Z axis and Cycles on the X or Y axis.  What's the 3rd quantity?  I believe I've already sent you code to convert tachometer pulses to RPMs, it would be a minor adaptation to convert to Cycles instead.

Brad Turpin

DIAdem Product Support Engineer

National Instruments

[cees10]

Hi Brad 

3rd axes would be deflection (distance)    of the amplitude in  time

Example   first sinus  Wave    has height   0  5  0 -5 0

last sinus  wave  0    20 0 -20 0 

Thanks Brad 

[Brad_Turpin]

Hi Cees,

I'm struggling again to understand your English.  Would you please list the data that you want on X, Y, and Z axes?  Was I correct in guessing that you want Cycles (Revolutions, Periods) on one of the axes?

Brad Turpin

DIAdem Product Support Engineer
National Instruments

[cees10]

I am sorry for my bad english brad

yes your correct  about cycles (revs,rpm ,periods)

as NI explains 1 period    

 

x  period   1 period  x 20  =  1 cycle  ,= 1 revolution

y amplitude

z nr cycles 

Cees 

[Brad_Turpin]

Hi Cees,

Based on that graph, I'd say you need to sum the values of the counter channel, then devide them by 20 to give you a channel that tracks the number of cycles/periods.  The ChnSum() ANALYSIS routine will sum the channel, and the ChnLinScale() ANALYSIS routine will enable you to multiply it by 0.05.  Both of these ANALYSIS routines are available "Basic Mathematics" palette in ANALYSIS.  After that you can sort the values by the periods channels, sending all the Period=1 data to one Group, say, all the Period=2 data to another Group, etc.

Do I already have a data set like this from you?  I have so many that I can't tell any more which is which.

Brad Turpin

DIAdem Product Support Engineer
National Instruments

[cees10]

Hi Brad

I have sent the file's to your email adresse

cees 

[cees10]

Sorry brad still struggling with it ,i simply do not get what i want thats why i posted  the file ,so you take a look at it if you want to show me (at least if you want and can) how to solve this

If i sum the file i get all period summed (values of it ) that not what i need,  i need 20 period  = i rev   

i need avg of  that rev to find  the ( so called zero point ) then from  zero point then   this the amplitude.of all 20 period in that rev

so if i have as this file shows   6525 data periods    /20 =326.25  rev

So i want to see in waterfall graph all 326.25 rev

cees