Power Supply Integration with Automated Test Machines

Programmable DC power supplies are commonly used in automated test systems to provide controlled and repeatable power to the Device Under Test (DUT).

Power-supply manufacturers usually provide their own PC software for configuration and monitoring. However, this software may not meet the requirements of an automated test sequence. In many applications, the power supply must operate as an integrated part of the test system.

Why Integrate a Power Supply with an Automated Test Machine?

For example, when a performance test starts, the LabVIEW application may need to automatically:

• Set output voltage

• Set output current

• Set voltage and current limits

• Configure resolution and other parameters

• Verify the programmed values

• Turn DC output ON

• Monitor voltage and current during the test

• Turn DC output OFF after test completion

This allows the power supply to follow the test sequence automatically without requiring separate manufacturer software.

Connecting a Power Supply Through USB

Many programmable DC power supplies provide USB connectivity for PC control.

The USB connection provides the physical communication path, while NI-VISA provides the software communication layer used by LabVIEW.

The basic architecture is:

LabVIEW Application → Instrument Driver → NI-VISA → USB → DC Power Supply

Depending on the instrument, other interfaces such as LAN, GPIB or serial communication may also be available.

Using NI-VISA and LabVIEW for Power Supply Control

Power-supply manufacturers sometimes provide LabVIEW-compatible instrument drivers. These drivers provide functions for configuring and controlling the instrument, such as:

• Set Voltage

• Set Current

• Set Limits

• Output ON/OFF

• Read Voltage

• Read Current

• Read Power

• Read Instrument Status

When a suitable manufacturer driver is available, PROLABS can integrate it directly into the LabVIEW application.

What If the Manufacturer Does Not Provide a LabVIEW Driver?

A manufacturer may provide PC software but not a suitable LabVIEW instrument driver.

When the instrument provides a documented communication protocol and command set, a custom LabVIEW instrument interface can be developed using NI-VISA.

LabVIEW provides tools and low-level VISA functions that can be used to communicate with the instrument, send commands, receive responses and develop application-specific instrument drivers.

This allows PROLABS to integrate different makes and models of programmable power supplies into automated test systems.

Power Supply as Part of the Test Sequence

A typical automated sequence can be:

Start Test
↓
Configure Power Supply
↓
Verify Parameters
↓
DC Output ON
↓
Execute Performance Test
↓
Read / Monitor Power Parameters
↓
Test Complete
↓
DC Output OFF

The power-supply parameters can also be displayed in the LabVIEW UI and recorded along with the test data.

How PROLABS Integrates Power Supplies

PROLABS integrates programmable DC power supplies into LabVIEW-based automated test systems using NI-VISA, manufacturer instrument drivers or custom-developed instrument interfaces.

This enables the LabVIEW application to configure, control, monitor and read back power-supply parameters as part of the complete test sequence.

PROLABS can integrate programmable power supplies from different manufacturers, subject to their available communication interface and documented command capabilities.

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