Using FOPEN() on COM Port Does Not Set RTS or DTR Bits

ID: Q103278

The information in this article applies to:

• Microsoft FoxPro for MS-DOS, versions 2.0, 2.5, and 2.5a

SUMMARY

After you use the FOPEN() command to open a COM port, the Request to Send (RTS) and Data Terminal Ready (DTR) COM lines are not set ON.

MORE INFORMATION

FoxPro for MS-DOS does the equivalent of the COPY command to the serial port. RTS and DTR are used in serial communications for buffering I/O. FoxPro does not buffer I/O to COM ports. The section on FOPEN() in the version 2.0 "Commands & Functions" and version 2.5 "Language Reference" manuals suggests that communications ports always be opened unbuffered.

Additional reference words: FoxDos 2.00 2.50 2.50a KBCategory: kbprg KBSubcategory:

Last Reviewed: April 17, 1995