sending data with serial port problem (16chars=ok, >17chars Not working)

[cvschie]

Hi,

I have a LED Sign with standard software to control messages (via
serial port). Because the limitations of the software I want my own
VB.net program.
With a serial analyzer program, I see all the data that the standard
program is sending to de LED sign.
With my ownprogram I send the same, and it works fine... except:
If I send a string to the LED Sign with a length of upto 16 chars it
works fine, but if the lengthe is 17 chars or more. The sign will nog
display it.
Any suggestions?
I allready tried the following:
-increase the send buffer
-split the string and use serialport.write("asdf") twice

Thanks in advance

 

[Thomas Lutz]

It may be that the sign has a 16 byte input buffer and when you send
it more than 16 bytes at one time, it cannot handle all the data. You
might try inserting a delay between each character or a delay between
each packet of 16 bytes that you send to the sign to give it enough
time to read in the data.