What you are saying still doesn't make sense or somehow seems backwards.
Perhaps you can attach a link to the manual for the device you are sending data to. Then we can see what format the data needs to look like.
Remember that bytes are just bytes. A value from 0 to 255. Whether that is a series of characters in a string, numbers in an array, or numbers stored in a PC's memory. It just so happens that you can have a string display that in several ways.
1. Normal - those values show up as characters based on the ASCII table in use.
2. Hex - those values show up in hex format with digits of 0-9,A-F Two at digits to a byte, and formatted to show a space between every 4 hex digits.
3. \code - comination of ASCII characters where they are readable, certain slash characters where they are meaningful (\t for tab, \r for carriage return) or \## where it is another non-printable, non-text based control character such as showing \00 or \01 or \FF for any bytes that don't fit in the previous categories.
4. Password, all values are just shown as asterisks to hide the underlying data.
But for all 4 of these, the underlying data is the same, it is just shown differently to the user viewing the front panel.
EDIT: While trying to give a more thorough explanation, it seems you've now discovered the thorn causing the problem.
