Metrologic Optimus R, Руководство по программированию

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Chapter 3 Terminal Specific Function Library 103
com_overrun
Purpose To check if overrun error occurs.
Syntax int com_overrun (int port);
int port; /* which COM port (1 or 2) to be checked */
Example if (overrun (1) > 0) clear_com (1);
/* if overrun, data stored in the buffer is not complete, clear them all */
Description This routine checks if overrun error occurs on COM 1 or COM 2.
Return If overrun occurs, it returns 1.
Otherwise, it returns 0.
See Also clear_com
nwrite_com
Purpose To send a specific number of characters through a specified COM port.
Syntax int nwrite_com (int port, char *s, int count);
int port; /* COM port to be used */
char *s; /* string to be sent out */
int count; /* number of characters to be sent */
Example char s[] = {"Hello\n"};
nwrite_com (1,s,2); /* send the characters "He" through COM 1 */
Description This routine sends the characters of a string one by one until the specified
number of characters are sent out.
Return If successful, it returns the character count.
Otherwise, it returns 0.
See Also write_com
open_com
Purpose To enable a specified COM port and initialize communication.
Syntax int open_com (int com_port, int setting);
int com_port; /* COM port to be opened */
int setting; /* port settings for COM 1 or COM 2 as shown below */