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nicjo
- 17th September 2008, 11:59
Hi everyone,

I've got a project that worked fine with a standard serial port using VB code slightly modified to that of Rentron.com. Basically grab 4 bytes with the first 2 being an instruction to do something and the other 2 being information. For example 'aa2500' aa instructs to put a count of 2500 into a text box, bb3000 current count of 3000 into another box and soforth. As I said worked fine with a standard serial port. Things don't to well with a usb-serial converter, errors everywhere. I am suspecting that the converter may be adding control characters amongst the output but I'm not sure.

I've seen that the sample provided in VB6, VBterm does remove these control characters such as LF, CR. Am I heading in the right direction??

Ta

john

skimask
- 17th September 2008, 13:39
Things don't to well with a usb-serial converter, errors everywhere. I am suspecting that the converter may be adding control characters amongst the output but I'm not sure.
I'd doubt it. USB-Serial converters don't (ok, shouldn't) modify the data and add characters as you suggest.
What does the RAW data look like? Do you have any control of that at either end?

Ioannis
- 17th September 2008, 16:45
Is your communication time critical? Maybe the converter puts some delay in the flow of data.

Ioannis

BrianT
- 17th September 2008, 23:52
I think you are seeing the same effect as I see when trying to run an RS232 boot loader through a USB to serial converter. The boot loader seems to be very fussy about send/receive character delays and some converters, some of the time, work while others don't work ever.

I have even managed to blow up the bootloader through a USB to serial converter and had to reload the bootloader via EPIC.

I suggest you try several different USB to serial converters.

HTH
BrianT