Hi All,

I am trying to transfer data over a VHF Radio to another VHF Radio. The radio is having a serial Port to interface with the PC. I have written an Application in Visual Basic using MSComm control. The protocol i have defined is a customised version of zmodem (for crash recovery). I am sending data in Text Mode. Is there anything like i cannot send "non-printable characters like Ack (Ascii 6)"? I am having some timing issue with the software.

 

Hi

You can add nonprintable characters to text using function CHR(3).

Regards
Andrzej
www.modbus.pl

 

<p>If software handshake (XON/XOFF) is used, you cannot send these characters.
<pre>
Decimal Octal Hex Binary Value
------- ----- --- ------ -----
(Data Link Escape)
017 021 011 00010001 DC1 (XON) (Device Control 1)
018 022 012 00010010 DC2 (Device Control 2)
019 023 013 00010011 DC3 (XOFF)(Device Control 3)
</pre>

 

Hi

i want to do the same which u have done, that is tranfer of data using radio modems. i need help. i don't know how to make serial port act as half duplex. if u will send me ur code i will be grtful. basically i am doing project on wireless fax. thats why need this. i will be waiting for urgent reply.

regards