Metrologic Optimus R, Programming Manual

Page: 111 / 241

Chapter 3 Terminal Specific Function Library 105
read_com
Purpose To read one character from the receive buffer of a specified COM port.
Syntax int read_com (int port, char *c);
int port; /* receive buffer of a specified COM port */
char *c; /* pointer to character returned */
Example char c;
if (read_com (1,c))
print ("char %c received from COM 1", *c);
Description This routine reads one byte from the receive buffer and then removes it from
the buffer. However, if the buffer is empty, it will return 0 for no action is
taken.
Return If successful, it returns 1.
Otherwise, it returns 0 to indicate the buffer is empty.
See Also nwrite_com, write_com
SetCommType
Purpose To set the communication type of a specified COM port.
Syntax int SetCommType (int port, int type);
int port; /* COM port to be set */
int type; /* the following communication types are available */
COMM_DIRECT 0 Direct RS-232
--- 1 Reserved
COMM_IR 2 Serial IR (via IR transceiver)
COMM_IrDA 3 Standard IrDA
COMM_RF 4 Bluetooth (SPP/DUN)
Example SetCommType (1, 2); /* set COM1 to IR communication */
Description This routine needs to be called BEFORE opening a COM port.
Note that the COM port mapping is different for each model of terminal, and a
COM port may not support all the communication types.
Return If successful, it returns 1.
On error, it returns 0 (i.e. invalid setting).
See Also open_com