Reading OMA trace from serial port

I am creating a desktop application where i want to read data from a serial port.
What we are doing is, we are Tracing eyeglass’s frames with attached Tracer device.
and we need to capture its OMA trace data.
I am able to catch serial data bit its not a Valid OMA trace data. It contains some garbage characters as below

Can anyone tell me if i need to make some settings to avoid these characters ?

Here is a image where we can see garbage data.

FS and GS for example are not F followed by S, etc.

These represents name for characters that are not printable. Have a look at ASCII Code - The extended ASCII table (

You will see

These codes are below 0x20 (which is a space). If all you need are the printable characters, then when reading your serial port, reject code < 0x20.

Back in the bad old days you’d have just seen a black box or possibly nothing at all. It’s the new glyphs in fancy text encoding you’re seeing to show you what the unprintable characters are. You’re getting the correct data, but the actual character that is being displayed for it is what Gilles posted.

If you don’t want to see those in the debug output you’ll have to do some further parsing on the data to remove them or turn them into something else but it really does look to me like it’s just being overly helpful and thus confusing.