ProSoft Technology MVI69-ADM - Manual (Page 261)

MVI-ADM ♦ 'C' Programmable Serial Port Library Functions
'C' Programmable Application Development Module Developer's Guide
ProSoft Technology, Inc. Page 261 of 342
February 20, 2013
MVIsp_GetCountUnsent
Syntax
int MVIsp_GetCountUnsent(int comport, int *count);
Parameters
comport Desired communications port
count Pointer to int to receive unsent character count
Description
MVIsp_GetCountUnsent returns the number of characters in the transmit queue
that are waiting to be sent. Since data sent to a port is queued before
transmission across a serial port, the application may need to determine if all
characters have been transmitted or how many characters remain to be
transmitted.
comport is the desired serial port and must be previously opened with
MVIsp_Open.
count points to an int that will receive the number of characters that have been
sent to the serial port but not transmitted. If the returned count is 0, all data has
been transmitted. If it is non-zero, it contains the number of characters put into
the queue with MVIsp_Putch, MVIsp_Puts, or MVIsp_PutData but that have not
been transmitted.
Return Value
MVI_SUCCESS count retrieved successfully
MVI_ERR_NOACCESS comport has not been opened
MVI_ERR_BADPARAM invalid pointer
Example
int count;
if (MVIsp_GetCountUnsent(COM2,&count) == MVI_SUCCESS)
{
if (count == 0)
printf("All chars sent\n");
else
printf("%d characters remaining\n",count);
}
See Also
MVIsp_Putch (page 251)
MVIsp_Puts (page 253)
MVIsp_PutData (page 255)