Serial Communication using MSCOMM32

Hi, I'm using the Microsoft communications control v6 in my program to communicate from my computer to a remote device using an rs232 port. I have successfully managed to get incoming data and process it, but I am having problems sending data. Here's my current code:


COleVariant aVar;
OLECHAR aArray[270];

aArray[0]='A';
aArray[1]='B';
aArray[2]='C';
aArray[3]='!';
aArray[4]= 26;
aVar = aArray;
CommControl12.put_Output(aVar);

I am using visual studio 9, and MSComm is imported as an active X control. The program compiles and runs, but no data is sent (this was checked by sending data to another computer). Any help would be appreciated!

To check whether you really send or receive data, use PortMon program:
http://technet.microsoft.com/en-us/s.../bb896644.aspx

Using ActiveX control in C++ is most complicated way of serial communications. ActiveX controls are for VB programmers. Most C++ programmers prefer to work with COM ports using plain API:
http://msdn.microsoft.com/en-us/library/ms810467.aspx

There are also number of COM port wrappers like:
http://www.codeproject.com/KB/system/cserialport.aspx
http://www.codeproject.com/KB/system/serial.aspx
which are more convenient for C++ developer than ActiveX control.

Thanks for the links. I'm looking into using the wrapper classes. I was wondering though if anyone knows how to solve my original code problem; the use of the active x control is currently widely used in my program.

Problem solved. We were using the wrong type of modem cable.