I currently can't look into your code,
however, common pitfalls with RS232:
- termination characters: in your case , are they deaktivated for read?
- timeout: does your read time out?
- something left in the buffer: flush the buffer before requesting data.
Greetings from Germany
Henrik
LV since v3.1
“ground” is a convenient fantasy
'˙˙˙˙uıɐƃɐ lɐıp puɐ °06 ǝuoɥd ɹnoʎ uɹnʇ ǝsɐǝld 'ʎɹɐuıƃɐɯı sı pǝlɐıp ǝʌɐɥ noʎ ɹǝqɯnu ǝɥʇ'