HP E8491A manual Turn off the autozero function iprintfe1412, Zeroauto OFF\n

Note The ‘I_O Config’ help file associated with the HP E8491A interface contains additional information on configuring the faceplate trigger ports.

Triggering Example The following program demonstrates how an external trigger received on the faceplate ‘Trig In’ port is routed to TTL trigger lines on the VXI backplane.

//TRIGSICL.CPP - This program demonstrates how trigger signals are

//generated and routed using the HP E8491A. The program uses SICL functions

//to generate and route a trigger signal from the face plate ‘Trig Out’

//port to VXI backplane trigger line TTLTRG4. The signal triggers the

//E1412 multimeter which then takes a burst of 10 readings.

#include "sicl.h" #include <stdio.h> #include <stdlib.h>

// project files: trigsicl.cpp, sicl32.lib

void main(void)

{

INST e8491;// E8491 SICL handle INST e1412;// E1412 SICL handle short i;

double dcv_rdgs[10];

//install SICL error handler ionerror(I_ERROR_EXIT);

//open a (SICL) interface session to the E8491A

//open a (SICL) device session to the E1412 e8491 = iopen("vxi");

e1412 = iopen("vxi,24");

//set up trigger routing; rout a trigger from the faceplate 'Trig In'

//port to VXI backplane TTL trigger line 4

ivxitrigroute(e8491, I_TRIG_EXT0, I_TRIG_TTL4);

//E1412 Multimeter configuration

//set a 50s timeout period for external trigger to occur itimeout(e1412, 50000);

//configure the multimeter for DCV measurements iprintf(e1412, "CONF:VOLT:DC 8.0\n");

// set the fastest aperture time iprintf(e1412, "VOLT:DC:APER MIN\n");

//turn off the autozero function iprintf(e1412, "ZERO:AUTO OFF\n");

Chapter 3 VXI Programming Using the IEEE 1394 Serial Bus 45