Chapter 5 RS-232 Library
© National Instruments Corporation 5-15 LabWindows/CVI Standard Libraries
The following values may be used only with the RS-485 serial driver developed by National
Instruments:
WIRE_4—Sets the transceiver to Four Wire Mode.
WIRE_2_ECHO—Sets the transceiver to Two Wire DTR controlled with echo mode.
WIRE_2_CTRL—Sets the transceiver to Two Wire DTR controlled without echo.
WIRE_2_AUTO—Sets the transceiver to Two Wire auto TXRDY controlled mode.
ComToFile
int nbytes = ComToFile (int COMPort, int fileHandle, int count,
int terminationByte);
Purpose
Reads from input queue of specified com port and write data to file specified by fileHandle.
Returns number of bytes successfully written to file. Bytes are read from input queue until count
is satisfied, terminationByte is encountered, or an error occurs, whichever occurs first.
Parameters
Input COMPort integer Range 1 through 32.
fileHandle integer File handle returned by
OpenFile.
count integer If 0, this value is ignored.
terminationByte integer If -1, this value is ignored.
Return Value
nbytes integer Number of bytes written to the
file.
Parameter Discussion
If count is zero, the function ignores it and terminates on terminationByte or error.
If terminationByte is -1, the function ignores it and terminates on count bytes read or an error.
If terminationByte is valid, the function stops when it encounters terminationByte.
terminationByte is removed from the input queue and is not written to the file. If
terminationByte is CR or LF, then CR-LF and LF-CR combinations are treated just as they are