Configuring the Digitizer Input

This program demonstrates the commands used to configure the digitizer’s input section. The program sets up the digitizer to take 10 readings on the

1V range of the digitizer’s single ended input port. This includes:

enabling/disabling the input ports

setting the input impedance

switching the 10 MHz filter into the signal path.

setting the signal range

INPUT.C

*RST;*CLS/* reset and clear the digitizer */

CONF1:ARR:VOLT (10),(@1) /* set 10 readings on channel 1, input port 1 */

INP3:STAT OFF

/* disable differential port 3 */

INP1:IMP 50

/* set input impedance to 50 ohms */

INP1:FILT ON

/* switch 10 MHz filter into signal path */

SENS1:VOLT:RANG 1

/* set 1V range */

READ?

/* initialize digitizer, fetch readings */

/* retrieve the readings from the digitizer */

Comments 1. Digitizer INPut Commands. The CONFigure command sets most of the (INPut) subsystem parameters to the same values as set by the INP commands listed in the program. The INPut commands were executed to show the context in which they are used.

2.Disabling an Input Port. When taking readings, it is not necessary to disable the channel’s input port that is not being used (INP3:STAT OFF). It was done in this program to show the versatility of the digitizer.

3.Digitizer Measurement Range. In this program, the measurement range is specified with the SENSe:VOLTage:RANGe command, rather than with the expected value parameter of the CONFigure command. For most applications, however, it is easier to specify an expected value. SENSe:VOLTage:RANGe can be used to change the signal range without changing the entire digitizer configuration with CONFigure.

50 Using the Digitizer

Chapter 2

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HP E1429A manual Configuring the Digitizer Input, Input.C