HP 34401A User Manual page 192

Chapter 6 Application Programs
RS-232 Operation Using Turbo C
RS-232 Operation Using Turbo C
The following example shows how to program an AT personal computer
for interrupt-driven
sent to the HP 34401A and responses received for commands that query
information. The following program is written in Turbo C and can be
easily modified for use with Microsoft Quick C.
RS-232 Operation Using Turbo C
#include <bios.h>
#include <stdio.h>
#include <string.h>
#include <dos.h>
#include <conio.h>
#define EVEN_7 (0x18 | 0x02 | 0x04)
#define ODD_7 (0x08 | 0x02 | 0x04)
#define NONE_8 (0x00 | 0x03 | 0x04)
#define BAUD300 0x40
#define BAUD600 0x60
#define BAUD1200 0x80
#define BAUD2400 0xA0
#define BAUD4800 0xC0
#define BAUD9600 0xE0
/* 8250 UART Registers */
#define COM 0x3F8
#define THR COM+0
#define RDR COM+0
#define IER COM+1
#define IIR COM+2
#define LCR COM+3
#define MCR COM+4
#define LSR COM+5
#define MSR COM+6
Continued on next page ’
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port communications. SCPI commands can be
COM
/* Even parity, 7 data, 2 stop */
/* Odd
/* None parity, 8 data, 2 stop */
/* COM1 base port address */
/* LCR bit 7 = 0 */
/* LCR bit 7 = 0 */
/* LCR bit 7 = 0 */
/* The rest are don't care for bit 7 */
parity, 7 data, 2 stop */
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