topic Re: Binary Conversion 16bit to 8bit in LabVIEW

Binary Conversion 16bit to 8bit

sout23 — Wed, 23 Sep 2015 06:45:49 GMT

Im having a little trouble making a labview VI for this process, where var1send and var2send are signed 16-bit integers

int8_t var1low = var1send & 0xff;
int8_t var1high = (var1send >> 8);
int8_t var2low = var2send & 0xff;
int8_t var2high = (var2send >> 8);

Any help would be awesome!

Re: Binary Conversion 16bit to 8bit

PeterFoerster — Wed, 23 Sep 2015 07:17:39 GMT

Hi sout,

does the "split number" VI do that for you? It splits a 16 bit number into two 8 bit numbers. You can find it under Programming >> Numeric >> Data Manipulation.

Re: Binary Conversion 16bit to 8bit

mikeporter — Wed, 23 Sep 2015 07:32:29 GMT

First, there's an issue with problem definition. You say the inputs are 16 bit but they are being anded with an 8 bit value. If the point is to isolate the least significant byte, just do that by splitting the 16 bit number.

Next you are shifting the original input by 8 bits (which will still result in a 16 bit value) and you are trying to assign it to an 8 bit value.

Frankly, it looks like the intent might be to assign the low byte of the input to the low byte of the output, and the high byte of the input to the high byte of the output. Or if the outputs are 4, 8 bit values all you need to do is split the input integer.

What is it exactly that you are trying to do?

Mike...

Re: Binary Conversion 16bit to 8bit

sout23 — Wed, 23 Sep 2015 09:06:04 GMT

I think your right, thanks for the help. The split number function should work.

Just one other thing, is there a function to convert a decimal into a signed 16-bit integer?

Re: Binary Conversion 16bit to 8bit

PeterFoerster — Wed, 23 Sep 2015 09:18:42 GMT

Yes, there is.

BTW, there also is a ton of tutorials available online that help you with these things:

3 Hour Introduction
6 Hour Introduction
LabVEW Basics
Self Paced training for students

The Function you're looking for is called "To Word Integer"

Self Paced training beginner to advanced, SSP Required
LabVIEW Wiki on Training
Learning NI
Getting Started with NI Products

Re: Binary Conversion 16bit to 8bit

sout23 — Wed, 23 Sep 2015 09:38:40 GMT

Sorry my mistake, i meant to say from a decimal to binary 16bit signed

Re: Binary Conversion 16bit to 8bit

PeterFoerster — Wed, 23 Sep 2015 09:52:28 GMT

Do you mean a boolean array of the Value? And number to boolean doesn't work?

Re: Binary Conversion 16bit to 8bit

sout23 — Wed, 23 Sep 2015 10:01:10 GMT

Everything i try, doesnt seem to work.

Basically, I can't seem to figure out how to convert a signed 16 bit decimal number into a signed 16bit binary number and then split that

Re: Binary Conversion 16bit to 8bit

PeterFoerster — Wed, 23 Sep 2015 10:16:37 GMT

Decimal and Binary just two representations of the same number. Right click on the Element >> Visible Items >> Radix; then click on the radix and select.

Splitting should work as described above.

If you still have questions, please include an example, as it's hard to guess what does work, when we don't know what you already tried.

Re: Binary Conversion 16bit to 8bit

sout23 — Wed, 23 Sep 2015 10:41:44 GMT

Ok, so this is basically what I want, i dont want to enter the number in as a binary number. Ive tried to use format into string to convert to binary, but I am not able to split the string into 2 seperate 8-bit bytes.

Not sure what other functions i can use to convert from decimal to binary except not in a string.

Re: Binary Conversion 16bit to 8bit

PeterFoerster — Wed, 23 Sep 2015 10:53:52 GMT

So, I assume, what I wrote earlier didn't work? Because it works on my end. See attached VI

Re: Binary Conversion 16bit to 8bit

sout23 — Wed, 23 Sep 2015 11:17:08 GMT

I can't seem to open this VI, it says my labVIEW isnt 2015 or something. Could you post a picture instead?

Re: Binary Conversion 16bit to 8bit

PeterFoerster — Wed, 23 Sep 2015 11:49:54 GMT

Re: Binary Conversion 16bit to 8bit

sout23 — Wed, 23 Sep 2015 11:55:16 GMT

Yes that is what i am looking for and that does work. But this is for a user interface. So i want the user to enter a decimal value, rather then a binary value. But i need to convert it to a binary to execute the function you have attatched

Re: Binary Conversion 16bit to 8bit

RavensFan — Wed, 23 Sep 2015 12:09:16 GMT

Then change the display mode of the control to decimal instead of binary!

Re: Binary Conversion 16bit to 8bit

sout23 — Wed, 23 Sep 2015 12:32:17 GMT

woops, of course. thanks for everyones help!

Re: Binary Conversion 16bit to 8bit

PeterFoerster — Wed, 23 Sep 2015 13:42:32 GMT

So many kudos were given that day...