Analog signal scaling in mitsubishi gx works 3

Hi Guys,
I'm Still looking for function block that is used in Mitsubishi GXWork3 for 4-20mA scaling.
Is there no Mitsubishi friend here?

Can you not write your own? That's what I'd normally do as the maths isn't complex.

Jonnie_R said:

Can you not write your own? That's what I'd normally do as the maths isn't complex.

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Well, I can write calculation but I still need to know the instruction for analog scaling and even instruction to call in a program.


Regards

scaling is easily done through module parameter setting, no FB needed at all

Dan247humble@yahoo

sczot said:

scaling is easily done through module parameter setting, no FB needed at all

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Really?
Interesting, could you please throw more light on the procedure?
I'll be grateful.

you can set your values there, analog range is by default -32k <> +32k


you can set it to whatever will fit your needs

sczot said:

you can set your values there, analog range is by default -32k <> +32k


you can set it to whatever will fit your needs

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Sczot, You have made my day. I really appreciate.

Please, Could you also tell me how to Call in a SubRoutine Program file? (like in Allen Bradley where JSR Instruction is used)How can I do this in GXWork3?

Scaling

Hi !

I need to know how i can convert 4-20mA to 0-5 meters.

Hope you can help me with that.

Thx

Khaled: I suggest you start a new thread unless you are doing it in GXWorks3 as the answer has already been posted, stating what PLC etc.
There area lot of old Threads here regarding scaling for example a simple one is if the min and max raw value is 0-32000 and your scale you want is 0-5.0
then divide 32000 by 50 = 640 (or 64.0)
Then divide the raw value by 640 so if the raw value = 16000 then 16000 / 640 = 25 (2.5) so that is half of the 5.0 which corresponds to half the max raw value. It is best to convert them all to real numbers do the maths then you will have more accurate results.
However, if your analogue raw does not start at 0 then you need to subtract the offset first.

Which PLC are you using as it matters, if FX5U then it is slightly different than say FX3 or Q series.
So for FX5 I suggest you create your code in an FB (Function Block) then you can call it in your program especially if you want to call it on a condition.
or if it is just another program block you want to call in the main scan then just create a new Program Block and add it to the Task.
Function Blocks do not need to pass parameters but then the labels (symbols) should be global ones so they are accessible by other programs.

khaled- said:

Hi !

I need to know how i can convert 4-20mA to 0-5 meters.

Hope you can help me with that.

Thx

Click to expand...

This is not nearly enough information for anyone to help you, but perhaps we can help you help yourself:



The problem is that your system will not read in the milliAmp value, it will read in a value, which value is called by many names:

• Raw Input
• Raw Analog Input
• Analog Input Value
• DN (Data Number)
• DN (Digital Number)
• etc.

Presumably

• You have a PLC
• A transducer is converting a 0-5m position of some object into a 4-20mA signal,
• The PLC has an analog input channel
• That input channel is converting that current signal into a value, which value
  • is typically a 16-bit signed integer,
  • is acting linearly with position and current

1. Is that correct?
2. What is the integer value when the position is 0m?
3. What is the integer value when the position is 5m?
4. Alternatively, what are the integer values for any two values, on near 0m and one near 5m?

Scaling questions come up very frequently on this forum; I suggest you do some searching. Here is one that explains what happens in scaling in some detail: https://www.plctalk.net/qanda/showthread.php?t=126614&highlight=scaling