Status Reporting by the RS-232 Library

The RS-232 Library returns status information through a global variable called rs232err. If this variable is negative after the function returns, an error occurred. Notice that many of the functions return a value in addition to setting the global variable. Usually, this value contains information about the result of the function that also can be used to detect a problem. Each function should be checked individually. You can use GetRS232ErrorString to get the error message associated with each RS-232 Library error code.

Note  If your program uses multiple threads, use the ReturnRS232Err function in place of the rs232err global variable.