Reading Binary Data from Serial Port

I need to read binary data from a serial port. The data is in the format of 23 single byte values. After the values are read I need to combine pairs of byte values (high  and low) to get a 16 bit value.

I have read text values from the serial port before but have no experience in binary data. How do I ....

1) read binary data into a variable?
2) convert high and low single byte values into one 16 bit value?

Some simple code examples would be appreciated.
allsoppAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

nmcdermaidCommented:
Here is a starting point for you:


Once you have loaded your data into a string from the COM port, you can use the Mid function to extract a single byte at a time.

Therefore to get the third of the 23 bytes out of your string (called sWholeString in this example), use:

sHigh = Mid(sWholeString,3,1)

That is a string. Then you can use Asc(sByte) to get the Ascii value.

iHigh = Asc(sHigh)

Then if your low byte is in the next byte, use this to get your 16 bit value:

sLow = Mid(sWholeString,4,1)

iLow = Asc(sLow)

iTotal = sHigh * 256 + iLow



Try it out and if it works and you want more detail let me know.
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
allsoppAuthor Commented:
Thanks. The actual equipment I need to talk to is arriving sometime this week. I'll try it out and respond then.
0
MsLimCommented:
thinking
0
Ultimate Tool Kit for Technology Solution Provider

Broken down into practical pointers and step-by-step instructions, the IT Service Excellence Tool Kit delivers expert advice for technology solution providers. Get your free copy now.

Steve-HowesCommented:
the parallel port is much easier to manipulate in vb, if you get dlportio from DriverLINX you can just use a function to return a value for the port,, but if the equiptment you are using will only support the serial port then it will be quite a bit harder to do
0
allsoppAuthor Commented:
The equipment is a radio tx/rx unit with a receiver that outputs to RS485 serial.
The code example you provided worked perfectly first time so the points are yours
0
nmcdermaidCommented:
Sounds like fun whatever you're doing!
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Visual Basic Classic

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.