Z-scale colors not as expected on Intensity Graph object

[neona]

I have a problem using Z-scale proprety nodes,when scaling some particular measurements.
Please, look at the attached vi for the problem description.
Many thanks for your help in advance.

Neona

[Xy]

Hi guy,

You needn't control the zscale offset and multiplier. You only want to display the input value with proper intensity color. So you should set the range to display. You only need to connect initial term scale and final term scale to the Zscale minimum and maximum.

[neona]

Sorry but this vi must work properly on all temperature range also with very low steps (step number up to 65500), but with these default settings, for example the TEMP ARRAY[i,j]=0 must be white?!

Many thanks

[GerdW]

Hello Neona,

in my experience Labview only supports up to 256 steps in the z-scale. "Z-Scale.MarkerVal" will take more than 256 colors,
but "ColorTable" is limited to 256 values. And both control the same element of the graph!
See also this thread:
http://forums.ni.com/ni/board/message?board.id=170&message.id=94994&query.id=2096#M94994

To present my data I took this way:
- I scaled the "good" part to a range of 1-254 (including)
- the "under limit" and "over limit" got values of 0 and 255
- the z-scale got 256 color values (range from 0 to 255) with color 0 and 255 designated to show "excess limit"

Hope this helps,
GerdW

[neona]

My problem however persists, also scaling to U8 values the Z-scale, "0" is not represented properly...
I must use offset and multiplier objects to scale measurements to the right scale in accord with initial, final and step values...
Look at this example.

Thx

[GerdW]

Hello neona,

I changed your example by creating a new intensity chart. In the z-scale I set some colors and it works. Sometimes it helps to recreate a control/indicator...

Best regards,
GerdW

[neona]

Maybe you didn't understand which is my real problem. I want that the Z-scale in the example start at 1 and finish at 509. 255 on TEMP ARRAY must lead to Black (means temp above 509°C) and 0 must lead to White (means temp below 1°C). 254 means that the temperature is from 507 and 509°C, 253 means temperature from 505 to 507°C...1 means from 1 to 3°C. So I must set the offset and multiplier.
I hope now is clear.

Many thanks

[GerdW]

Hello neona,

ach so...

Why don't you scale the data by yourself? It's just two arithmetic functions... And yes: it should work like described in the LabView help.
I just tested the behaviour again:
I changed the datatype of your test data to I16 and then changed a "0" to "-1" in the test data. Then the graph also showed a "lower color" point. This makes sense as a "0" gets scaled to "1" (2*0+1, mult=2, offset=1) and this gives you blue instead of "lower color". So it seems you need to make your own scaling anyway.

Best regards,
GerdW

[GerdW]

Hello neona,

after reading the whole thread again, it's just a question of the proper scaling numbers.
You set an offset of 1 and a multiplier of 2. Then you input a zero and want that to be zero again (below your minimum of 1!). That's not possible with standard mathematics (0 <> 2*0+1). So you have to change your scaling factors or the used mathematics. I would change the used mathematics (that means: make my own scaling) as this gives you more freedom. You can make a logarithmic scale, mark important values and so on.

Best regards,
GerdW

[neona]

Ok, many thanks for your help and for your patience.

Best Regards
Neona