A2007U Labview manual
Table of Contents
1 Overview
This manual describes the usage of the LabVIEW driver created for usage in combination with a Divize A2007U Current Loop Tester.
The following details describe this driver project (following NI template):
| Instrument Driver Technology | Plug and Play (project) |
| Supported Language(s) | LabVIEW 13 |
| Supported Regional Settings | English and Universal desktops (period or comma separator for number decimal point) |
| Supported Models | Divize USB Current Loop Testers |
| Models Tested | Divize A2007U USB/NFC Current Loop Tester |
| Interfaces | USB 2.0 |
| Firmware Revision Tested | ... |
| Certified | NO |
| NI Supported | NO |
| Source Code Available | YES |
| Driver Revision | 1.0, 08/2014, LV_13 |
| Original Release Date | August 2014 |
| Current Revision Date | August 2014 |
2 Required Software
Some software components need to be installed before using this instrument driver. The minimum versions of these components are listed below, and can be downloaded from the download Web site.
LabVIEW:
- LabVIEW 2010
- LabVIEW 2013
NI VISA:
- VISA 5.0 for LabVIEW 2010 compatibility
- VISA 5.4 for LabVIEW 2013 compatibility
Note: VISA has additional software requirements.
For example, if using the IEEE-488 port, NI-VISA requires that NI-488.2 be installed on your system. Check with VISA help for additional support software and hardware requirements.
LabVIEW (and other programs) require to have the FTDI FT231X serial driver installed. On Windows this driver should get installed automatically, on Linux it most likely is installed by default.
3 Installation Instructions
Obtain a copy of the driver software. It is packaged in a archive file. The software is available from the Divize website.
3.1 Microsoft Windows
- Use Windows® Explorer and navigate to folder: ...\Program Files \National Instruments \LabVIEW...\instr.lib
- Create a new folder: A2007U
- Extract the file you downloaded into the "A2007U" folder
- You will now have a "...\instr.lib\A2007U\" folder containing multiple files and the "Public", "Private" and "Examples" folders
These files make up an instrument driver. The menu files allow you to view the instrument driver VIs from the Functions palette. The other files contain the instrument driver VIs.
3.2 Linux
- Use your file explorer and navigate to folder: /usr/local/natinst/LabVIEW.../instr.lib (installation location may differ, please refer your local LabVIEW installation for exact location)
- Create a new folder: A2007U
- Extract the file you downloaded into the "A2007U" folder
- You will now have a ".../instr.lib/A2007U/" folder containing multiple files and the "Public", "Private" and "Examples" folders
These files make up an instrument driver. The menu files allow you to view the instrument driver VIs from the Functions palette. The other file contain the instrument driver VIs.
4 Accessing the Driver in LabVIEW
There is normally no need to view the library file because the driver functions may be picked from a palette menu.
- Right-click on a blank place on the VI diagram See the "Functions" palette open. Navigate:
Functions → Instrument I/O → Instrument Drivers → Divize A2007U
- Alternately, click diagram’s menu bar: Window → "Show Functions Palette" and navigate the above menus
Figure 4.1 The A2007U palette
5 Using the Instrument Driver
5.1 Explaination of Device VIs
5.1.1 Initialize.vi – Device Connection Initialization
Figure 5.1 Initialize.vi external interfaces
| Port | Direction | Required | Description |
| VISA resource name | in | required | Resource name input, holds VISA name to device port |
| Serial Configuration | in | optional | Alternative serial configuration. Default should suffice |
| error in (no error) | in | optional | Error input, used to chain multiple VIs |
| VISA resource name out | out | required | Resource name output, connect to other device VIs |
| error out | out | optional | Error output, used to chain multiple VIs and/or diagnose problems |
Establishes communication with the instrument, performs an instrument identification query and resets the instrument.
Call this VI before calling other instrument driver VIs for this instrument. Generally you need to call the Initialize VI only once at the beginning of an application.
5.1.2 Close.vi – Close Device Connection
Figure 5.2 Close.vi external interfaces
| Port | Direction | Required | Description |
| VISA resource name | in | required | Resource name input, holds VISA name to device port |
| error in (no error) | in | optional | Error input, used to chain multiple VIs |
| error out | out | optional | Error output, used to chain multiple VIs and/or diagnose problems |
Terminates software connection to the instrument.
5.1.3 Reset.vi – Reset Device
Figure 5.3 Reset.vi external interfaces
| Port | Direction | Required | Description |
| VISA resource name | in | required | Resource name input, holds VISA name to device port |
| error in (no error) | in | optional | Error input, used to chain multiple VIs |
| VISA resource name out | out | required | Resource name output, connect to other device VIs |
| error out | out | optional | Error output, used to chain multiple VIs and/or diagnose problems |
Resets the instrument buffers and sends default setup commands to the instrument.
5.1.4 Revision Query.vi – Get Device Firmware Revision
Figure 5.4 Revision Query.vi external interfaces
| Port | Direction | Required | Description |
| VISA resource name | in | required | Resource name input, holds VISA name to device port |
| error in (no error) | in | optional | Error input, used to chain multiple VIs |
| VISA resource name out | out | required | Resource name output, connect to other device VIs |
| Instrument Driver Revision | out | optional | The LabVIEW instrument driver revision |
| Instrument Firmware Revision | out | optional | The instrument firmware revision |
| error out | out | optional | Error output, used to chain multiple VIs and/or diagnose problems |
5.1.5 Serial Query.vi – Get Device Serial Number
Figure 5.5 Serial Query.vi external interfaces
| Port | Direction | Required | Description |
| VISA resource name | in | required | Resource name input, holds VISA name to device port |
| error in (no error) | in | optional | Error input, used to chain multiple VIs |
| VISA resource name out | out | required | Resource name output, connect to other device VIs |
| Instrument Serial | out | required | Instrument serial number |
| error out | out | optional | Error output, used to chain multiple VIs and/or diagnose problems |
5.1.6 Set Output.vi – Set Output Value
Figure 5.6 Set Output.vi external interfaces
| Port | Direction | Required | Description |
| VISA resource name | in | required | Resource name input, holds VISA name to device port |
| Current Level | in | required | Current level to set the instrument to. Measured in mA. |
| error in (no error) | in | optional | Error input, used to chain multiple VIs |
| VISA resource name out | out | required | Resource name output, connect to other device VIs |
| error out | out | optional | Error output, used to chain multiple VIs and/or diagnose problems |
5.1.7 Fetch Output.vi – Get Output Value
Figure 5.7 Fetch Output.vi external interfaces
| Port | Direction | Required | Description |
| VISA resource name | in | required | Resource name input, holds VISA name to device port |
| error in (no error) | in | optional | Error input, used to chain multiple VIs |
| VISA resource name out | out | required | Resource name output, connect to other device VIs |
| Actual Current Level | out | required | Current level the instrument is set to. Measured in mA |
| error out | out | optional | Error output, used to chain multiple VIs and/or diagnose problems |
5.1.8 Enable Power.vi – Enable Current Loop Powering
Figure 5.8 Enable Power.vi external interfaces
| Port | Direction | Required | Description |
| VISA resource name | in | required | Resource name input, holds VISA name to device port |
| Enable Loop Power | in | required | Enable or Disable the loop powering feature of the instrument |
| error in (no error) | in | optional | Error input, used to chain multiple VIs |
| VISA resource name out | out | required | Resource name output, connect to other device VIs |
| error out | out | optional | Error output, used to chain multiple VIs and/or diagnose problems |
Warning: Wrongly enabling the loop power can damage the instrument and/or other devices connected to it.
5.2 Examples
To verify communication with your instrument and test a typical programmatic instrument operation, you should first open the Getting Started or Example VIs the instrument driver. Look over each of the controls and set them appropriately. Generally, with the exception of the address field, the defaults for most controls will be sufficient for your first run. You will need to set the instrument resource name appropriately. After running the VI, check to see that reasonable data was returned and an error was not reported in the error cluster.
After you have verified basic communication with your instrument, you might want to customize instrument control for your needs. If your application needs are similar to the Getting Started or Example VI, the simplest means of creating a customized VI is to save a copy of the Getting Started or Example VI by selecting "Save As" from the File menu. You can then modify this example to meet your specific needs.
For more details, reference the LabVIEW Help under Help → VI, Function, & How-To Help.
5.2.1 Loop Powered.vi – Basic Usage
Figure 5.9 Loop Powered.vi example block diagram
This example shows the basic usage of the most common VIs.
From left to right: the device connected as VISA resource name is initialized, the loop power is enabled/disabled based on the value of the Enable Loop Power front panel switch. A new current value is set according to the value of the Current Level dial. The value of the Current Loop Tester is fetched and shown on the Actual Current Level indicator. At last the device connection is closed.
5.2.2 Random.vi – Setting a Random Value
Figure 5.10 Random.vi example block diagram
This example is based on the previous example. In this demo however the new current value is based on a random value. This VI can be run continuously while waiting Wait for seconds between itterations.
6 Trouble Shooting
Some common issues are discussed throughout this chapter.
6.1 The A2007U is not recognized as serial device on Linux
Because of the internal settings of the used communication hardware it is possible that Linux refrains from automatically mounting the A2007U Current Loop Tester as serial device.
The following steps may solve this issue:
- Plug the device into a free USB port
- The device could be recognized, to check run following command to list all USB serial devices
ls -al /dev/ttyUSB*
- We need the device id. Run the following command and search for the device with iSerial set to A2007U-00X
lsusb -v
- Note the idVendor and idProduct for the found device
- Unload the FTDI kernel module
modprobe -r ftdi_sio
- Reload the FTDI kernel module while forcing to recognize the A2007U Current Loop Tester. Replace the idVendor and idProduct (without < and >)
modprobe ftdi_sio vendor=<idVendor> product=<idProduct>
- The device should now be recognized, to check run the following command to list all USB serial devices
ls -al /dev/ttyUSB*
6.2 Permissions on Linux prevent my from using the A2007U
Some Linux distributions need root rights to be able to access serial devices.
One method of solving this issue is adding the user which needs access to the appropriate group:
- Add user to the dialout [A] [A] The name of this user group may differ for your distribution. group using the following command replacing the user placeholder:
usermod -a -G dialout <user>
6.3 LabVIEW does not show the A2007U device as VISA resource on Linux
Sometimes LabVIEW does not automatically add USB serial devices to the VISA resource list. This problem however could also have other causes, please also check the other trouble solving sections.
Adding a USB serial device to NI VISA:
- Add USB serial devices to serial devices list (add as many device names as needed):
echo "labview.serialDevices: /dev/ttyUSB0:/dev/ttyUSB1:/dev/ttyUSB2/" > ~/.labviewrc
If the above step does not solve the issue please refer to the NI VISA manual provided with your installation.
6.4 Test communication with terminal emulator.
The communication to the A2007U can be verified with a terminal emulation program. Teraterm for Windows or GTKTerm for Linux.
To test the communication:
Tera Term terminal emulator for Windowsl
- Start the terminal emulation program.
- Select the USB-com port the A2007U is connected to.
- Set the baudrate to 9600 baud, 8 databits, No parity, 1 stop bit.
- Enter *hlp;
- The A2007U will display a command summary.
A detailed explanation of the CLI commands is listed on the A2007U software page.
© Divize b.v. ; February 17, 2016 Last update: February 14, 2021.