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Portable One GPIB programming with VEE

Created 08 Jun 2009

Question:
I am having a problem programming the Audio Precision Portable One with direct I/O over GPIB using HPVEE. The read command "M1?" gives a timeout error. Please give me a sample HPVEE program to illustrate reading the measured input voltage on the Portable One.

Answer:
At AP, we do not use, nor do we support the HP (now Agilent) VEE programming language. However, controlling an instrument over GPIB essentially involves writing command strings to the instrument and reading its response strings. As long as the command strings have the correct syntax and are in the right sequence, your GPIB program should work properly, regardless of which programming language you are using.

The Audio Precision GPIB Talker Listener Utility (available in the 2700 Programmer's Starter Kit 2700-PROG) is a great tool for debugging GPIB instrument communication issues. Although developed for the 2700 Series analyzers, this utility works with all Audio Precision GPIB equipped instruments. The utility simplifies communication with GPIB instruments and provides a convenient Windows interface that makes it simple to send commands to an instrument and read back the instrument response.

Figures 1 and 2 below are screen shots that illustrate sending the following commands to the Portable One:

*CLS;                                           ‘clear status
INPUT GAGB;                             ‘set the inputs to Generator A and Generator B
OUTPUT
ON;                                               ‘turn on the generator
GAMPLITUDE-10 DBV;              ‘set the amplitude to -10 dBV
GFREQUENCY 500 HZ;              ‘set the frequency to 500 Hz
FUNCTION LEVEL;                    ‘select the Level function
SETTLE ON;                                 ‘turn on settling
*CLS;                                            ‘clear status
M1?;                                              ‘read main meter (left meter on front panel)
M2?;                                              ‘read secondary meter (right)

 

Figure 1. The GPIB Talker Listener Utility.

 

Figure 2. Sending a string greater than 255 characters long.

The Portable One’s response to the M1? and M2? commands is shown in Figure 3.

Figure 3 Response to the M1?; M2? Commands (A = 313.3 mV, B = 316.2 mV).

If you don’t have access to the Audio Precision GPIB Talker Listener Utility, there may be a similar utility bundled with the GPIB interface used in your PC. For example, the Measurement and Automation Explorer software, which comes with National Instruments GPIB interfaces, includes a utility to send and read strings from GPIB devices.

slx 4040
jb

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