How to read register storaged in IEEE 754

[CLRSB]

Hi!

I need to build an application to read registers from my gauge. Application is almost finished but values i get on from holding register are different than values on my gauge (ex. i have voltage 230V on gauge, and values about 20k in application). Gauge stores values in IEEE 754 32-bit format and I have no idea how to read it to get correct value. I saw it's possible with using "Type cast", but i don't know how to configure it, I am totally newbie in LabVIEW. I will be much grateful if someone could show me a VI with reading from IEEE 754 option, or just tell me how to do it in detail (what to click, what to write, etc :)) 

Sorry for my english, I hope I didn't make many mistakes 🙂 

Greets 🙂

[GerdW]

Hi CLRSB,

you should note the data representation of your input values. I assume you receive a string:

The upper solution is using TypeCast, while the lower one uses DeserializeString. The second solution is more versatile as you can adapt the byte ordering easily…

[CLRSB]

Thanks for reply 🙂 I'm trying to do something like You just showed me, bu i can't wire it (still getting errors). Could You take a look on my app?

[GerdW]

Hi clrsb,

you did not use any of the shown solutions! Why don't you?

You may need to change byte ordering...

[CLRSB]

Oh sorry, wrong file. I made somthing like this

[altenbach · Accepted solution]

Notice your red dots, they indicate a data type mismatch. Remove the byte array to string, because it truncates your U16 array elements to U8. Typecast and unflatten accepts U16 arrays directly. (corrected, see answer below)

Also change your "holding registers" to a diagram constant (righ-click terminal...change to constant). Only the type matters, the data is irrelevant here. (Shouldn't it be a scalar SGL instead?)

Sorry, I don't have the toolkit so I am missing your subVI.

[CLRSB]

Unflatten dont accept this array 😕

[altenbach]

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@CLRSB wrote:

Unflatten dont accept this array 😕

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Yes, of course. Sorry about that. Insert a typecast (with type disconnected, producing a string) before wiring to the unflatten function.

[CLRSB]

Thank You very much for Your help. Greets 🙂