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DriveTest Calibration Set

Document version 1.0, 04.01.2018
Author Fabian Töpper

Purpose

A software tool and hardware to measure DriveTest test system current and voltage and create a calibration report.

Scope of Delivery

Software

  • One license for DriveTest Calibration Tool. Please inquire DriveTest for activation.
  • Software delivered as download or pre-installed on computers delivered by DriveTest. For download, please inquire DriveTest.

DriveTest e-mail: info@DriveTest.de.

Hardware

Cables

  • 1 yellow cable, 1m. 4mm Laboratory Safety Connectors on both ends
  • 1 green cable, 1m. 4mm Laboratory Safety Connectors on both ends
  • 1 red cable, 1m. 4mm Laboratory Safety Connector and 4mm Laboratory Connector,
  • 1 black cable, 1m. 4mm Laboratory Safety Connector and 4mm Laboratory Connector,

Equipment

  • 1 DriveTest Calibration Load Box

  • 1 Calibration Connector

  • 1 National Instruments USB-4065 Digitial Multimeter. Includes USB cable.

Introduction

DriveTest Calibration Tool is a Windows software for easy current and voltage measurement of DriveTest Test Systems under changing load conditions. A calibration report in HTML file format is generated automatically by the software. Calibration Tool is used in combination with one or two IVI compatible digital multimeters and a cascade of load resistors.

Complete Calibration Setup

The pictures below shows the simplified schematics of a complete current and voltage calibration setup. Calibration compares the internally measured current or voltage of the Unit Under Test with the externally measured values provided by the calibration device. Multiple current ranges can be examined by applying different Power Supply setpoint voltages and loads in the Load Box.

Current Calibration, simplified schematic

 Current Calibration

Voltage Calibration, simplified schematic

 Voltage Calibration

Unit Under Test

The Unit Under Test is the system which is supposed to be calibrated, e.g. a DriveTest Test System. It typically contains a Power Supply with programmable voltage and maximum current. A Switch device cuts the connection between power supply and load. It is possible to use Calibration Tool with systems containing a fixed voltage / fixed maximum current Power Supply and no Switch device.

Calibration Tool assumes that both Power Supply and Switch are controlled and monitored via National Instruments I/O modules. The physical I/O lines connected to power supply and switch are utilized by so called Global Virtual Channels, which are pre-configured with DriveTest test systems. Global Virtual Channels are managed by National Instruments software Measurement & Automation Explorer.

Calibration Equipment

Calibration Load Box

For current and voltage measurement resistive loads are applied to the test system. They are contained in a handy box with laboratory plugs, making it easy to apply a series of loads. The current flowing through the load resistor is measured via a shunt resistor.

Caution! Box can get hot when in use.

Calibration Connector

The Calibration connector provides an easy way to connect load resistors via the Calibration Load Box and voltage probes. It can be directly plugged in to the standard DriveTest Test System Connector as a replacement for the Unit Under Test Adapter.

Digital Multimeter - DMM

Calibration requires a reference measurement with an external trusted measurement device. To calibrate DriveTest test systems, one or two IVI compatible Digital Multimeters (DMM) for Windows PC connection are required. IVI is a standard driver abstraction for laboratory instrumentation. It enables Calibration Tool to access any DMM which comes with an IVI DMM driver.

Calibration Tool allows the configuration of a “Primary DMM” and a “Secondary DMM”.

  • Current Calibration
    • Primary DMM: Required. Measures voltage drop over the Calibration Load Box shunt resistor. Calibration Tool calculates the current.
    • Secondary DMM: Optional. Measures voltage at the Test System Connector to identify voltage drop along connection cable.
  • Voltage Calibraton
    • Primary DMM: Required. Measeures voltage at the test system connector
    • Secondary DMM: not used

Always connect multimeters for voltage measurement.

Software Installation

DriveTest Calibration Tool is Windows 32bit software for Windows 7, 8 and 10. It comes as a regular Windows installer. Execute setup.exe and follow the instructions on the screen. DriveTest recommends to use default installation folders.

Prepare Calibration System

DAQmx Global Virtual Channels

Calibration Tool requires National Instruments DAQmx Global Virtual Channels (“GVC”) to set and measure current and voltage output. Optionally, Calibration Tool can use GVCs to control a switch connecting the power lines to the Unit Under Test.

NI-DAQmx Global Virtual Channels in National Instruments Measurement & Automation Explorer Use National Instruments Measurement & Automation Explorer (“MAX”) to manage Global Virtual Channels. It installs with DriveTest Calibration Tool.

Use the table below to check in MAX if the required GVCs are available. Make sure the channels link to the proper physical channels.

Purpose DriveTest Standard Channel Name Calibration Type Necessity
Power Supply Voltage Setting Power_Supply_Voltage Current, Voltage Required
Power Supply Current Setting Power_Supply_Current Current, Voltage Required
Power Supply Voltage Output Power_Supply_Voltage_Mon Current, Voltage Required
Power Supply Current Output Power_Supply_Current_Mon Current Required
Power Switch Control Input 1 Power_Switch_1 Current, Voltage Optional
Power Switch Control Input 2 Power_Switch_2 Current, Voltage Optional

To create a new Global Virtual Channel, right click “NI-DAQmx Global Virtual Channels” in the left hand side navigation tree and select “Create new DAQmx Channel…”.

If the default channels need to be adapted, select the channel in the left hand side navigation tree. In the configuration pane on the right hand side, right click the channel name and select “Change Physical Channel”.

IVI Devices

DriveTest Calibration Tool relies on a hardware abstraction scheme called IVI to communicate with the Primary and Secondary DMM. This allows you to use any IVI compatible device which supports the IVI DMM class.

With installation, Calibration Tool brings support for National Instruments USB-4065 and HP / Agilent / Keysight 34401A. It can be necessary to adapt the Resource Descriptor, that is the device name (“Dev1”) or the COM Port, in the IVI Driver Session in NI MAX at the location seen in the screenshot below (usb4065 respectively).

A detailed description how to set up IVI with NI MAX can be found on the National Instrument website: Using Measurement & Automation Explorer to Configure Your IVI System

Current Calibration

Hardware Setup

  1. Connect the green and yellow Shunt Outputs of Calibration Load Box with your primary Digital Multimeter (DMM). Connect the green output with your DMM's COM and the yellow output with the DMM's voltage input.
  2. Connect the Calibration Connector black COM male connector with the Calibration Load Box black COM female plug. Leave the red load connector unconnected. Keep the open end in a safe position.
  3. Plug in the Calibration Connector to the Test System Connector
  4. Optional: Connect the black and red Voltage Probe Wires on the one end to the Calibration Connector where it says “Measure Voltage”. Plug the other ends of the wires into the secondary Digital Multimeter (DMM). At your DMM, use the black COM plug and the plug for voltage measurement.
  5. Connect the primary and optionally secondary Digital Multimeter to the PC

The maximum current will be in the range of the quotient of highest voltage and lowest resistor value you configure to be used: I=U/R. Make sure your wires are suitable for the expected maximum current.

Software Setup

  1. Start software DriveTest Calibration Tool
  2. Tab Settings Fill out the drop down listbars with correct values for your channels and devices which you previously configured in NI MAX
    • DMM Settings
      • Primary IVI DMM Device: Select your primary Digital Multimeter.
      • Enable Secondary DMM: Set the checkmark if a secondary Digital Multimeter for voltage measurement is available
      • Secondary IVI DMM Device: Select your secondary Digital Multimeter.
    • Switch Settings
      • Enable Switch: Set the checkmark if you have a power Switch device between Power Supply and Unit Under Test
      • Switch Right: Select the NI DAQmx Global Virtual Channel which controls the “positive/right” switch state
      • Switch Left: Select the NI DAQmx Global Virtual Channel which controls the “negative/left” switch state
    • Power Supply Settings
      • Power Supply Voltage is programmable: Set the checkmark if the Power Supply voltage output is programmable via a control voltage.
      • Voltage Set: Select the NI DAQmx Global Virtual Channel which controls the Power Supply voltage
      • Voltage Monitor: Select the NI DAQmx Global Virtual Channel which reads the Power Supply voltage
      • Power Supply Current is programmable: Set the checkmark if the Power Supply maximum current output is programmable
      • Current Set: Select the NI DAQmx Global Virtual Channel which controls the Power Supply maximum current
      • Current Monitor: Select the NI DAQmx Global Virtual Channel which reads the Power Supply current
  3. Tab Current Calibration Select the desired resistor and voltage values.
    • Available Resistor Plugs
      • 0.5R .. 10R: Set checkmarks next to the resistor values you want to use for calibration. Value unit is Ohm.
    • Voltage
      • 10V .. 14V: Set checkmarks next to the voltage values you want to use for calibration.
      • Custom Voltage: Set a checkmark and enter a custom voltage for calibration. This is required when using a non-voltage-programmable Power Supply.
    • Settings
      • Shunt Resistance [Ohm]: Enter the Shunt Resistor value of the load device in Ohm.
    • Start: Begins the calibration process

Start Calibration

  1. Tab Current Calibration, click button Start
  2. Follow the instructions on the screen

Create Calibration Report

  1. Tab Report Fill out details to appear on the Calibration Report.
    • Operator: Name of the person who performed the calibration process.
    • Calibrated Device: Name and serial number of the calibrated device
    • Primary DMM: Details like name and serial number of the primary Digital Multimeter which was used in calibration process
    • Secondary DMM: Details like name and serial number of the secondary Digital Multimeter which was used in calibration process
    • Allowed Deviation
      • percent: set checkmark and enter percent value to allow a relative deviation of the calibrated current to the current measured by the Primary DMM.
      • absolute: set checkmark and enter absolute value in A to allow a deviation of the calibrated current to the current measured by the Primary DMM.
    • Create Report (HTML): Click to generate the report in HTML format. The default web browser opens automatically and shows the report
  2. Web Browser
    • Check the report and correct details in Calibration Tool if necessary. Create report again if details changed.
    • Save Report with your browser. The HTML file is self-contained, meaning no additional files like images are required.

A report is created for last performed calibration process.

A report can be created multiple times with different deviation settings.

Voltage Calibration

Hardware Setup

  1. Connect the Calibration Connector black COM and red “Load Resistance” load connectors with your primary Digital Multimeter. Calibration Connector black COM goes to the DMM's COM and red “Load Resistance” connector to the DMM's voltage input.
  2. Plug in the Calibration Connector to the Test System Connector

Software Setup

  1. Start software DriveTest Calibration Tool
  2. Tab Settings Fill out the drop down listbars name below with correct values for your channels and devices which you previously configured in NI MAX
    • DMM Settings
      • Primary IVI DMM Device: Select your primary Digital Multimeter.
      • Enable Secondary DMM: unset the checkmark
      • Secondary IVI DMM Device: This input is disabled when checkmark Enable Secondary DMM is not set.
    • Switch Settings
      • Enable Switch: Set the checkmark if you have a power Switch device between Power Supply and Unit Under Test
      • Switch Right: Select the NI DAQmx Global Virtual Channel which controls the “positive/right” switch state
      • Switch Left: Select the NI DAQmx Global Virtual Channel which controls the “negative/left” switch state
    • Power Supply Settings
      • Power Supply Voltage is programmable: Set the checkmark if the Power Supply voltage output is programmable via a control voltage.
      • Voltage Set: Select the NI DAQmx Global Virtual Channel which controls the Power Supply voltage
      • Voltage Monitor: Select the NI DAQmx Global Virtual Channel which reads the Power Supply voltage
      • Power Supply Current is programmable: Set the checkmark if the Power Supply maximum current output is programmable
      • Current Set: Select the NI DAQmx Global Virtual Channel which controls the Power Supply maximum current
      • Current Monitor: This selection is not required for Voltage Calibration.
  3. Tab Voltage Calibration Select the desired voltage values.
    • Voltage Steps
      • 1V .. 18V: Set checkmarks next to the voltage values you want to use for calibration.
      • Custom Voltage: Set a checkmark and enter a custom voltage for calibration. This is required when using a non-voltage-programmable Power Supply.
    • Start: Begins the calibration process

Start Calibration

  1. Tab Voltage Calibration, click button Start
  2. Follow the instructions on the screen

Create Calibration Report

  1. Tab Report Fill out details to appear on the Calibration Report.
    • Operator: Name of the person who performed the calibration process.
    • Calibrated Device: Name and serial number of the calibrated device
    • Primary DMM: Details like name and serial number of the primary Digital Multimeter which was used in calibration process
    • Secondary DMM: This input is disabled. Secondary DMM is not used with Voltage Calibration
    • Allowed Deviation
      • percent: set checkmark and enter percent value to allow a relative deviation of the calibrated voltage to the voltage measured by the Primary DMM.
      • absolute: set checkmark and enter absolute value in V to allow a deviation of the calibrated voltage to the voltage measured by the Primary DMM.
    • Create Report (HTML): Click to generate the report in HTML format. The default web browser opens automatically and shows the report
  2. Web Browser
    • Check the report and correct details in Calibration Tool if necessary. Create report again if details changed.
    • Save Report with your browser. The HTML file is self-contained, meaning no additional files like images are required.

A report is created for last performed calibration process.

A report can be created multiple times with different deviation settings.

Change Log

Installer Versions

  • 1.0.8
    • Created 10.11.2017
    • Improved Selection of Channels and Devices
    • Improved User Experience
    • Custom Voltage with Current Calibration
calibration_tool.txt · Last modified: 2018/01/09 13:29 by fabian