Recommend NI products for my application (controlling several instruments at once)

[Mr_Johnson]

I'm new to Labview,  currently using only the trial version.      There's money in my budget to buy some control software but I need to qualify my needs.

What I'm looking to do is control several pieces of test equipment as a single system, allowing me to perform automated measurements on conventional

and digital two way radios.

Here is the list of equipment that I want to control:

First, my controller is a Rohde & Schwarz PSL 3.   Fully GPIB enabled and ready.  It's the PC that the control software will reside on.

Equipment:

Rohde & Schwarz FSEA 30 spectrum analyzer with option B7 digital modulation analysis package

Second FSEA 30, same configuration

R&S AMIQ4 I/Q modulation generator (Files for it generated from software residing on the PSL3)

R&S SMY 02 analog signal generator

Agilent E4431B analog/digital signal generator

Agilent E4406A spectrum analyzer/digital radio test set

Agilent E4418B RF power meter with sensor

General Dynamics R2670B service monitor

A typical application will be to perform a conventional radio test on a VHF or UHF analog channel.    

The idea is to enter the transmit and receive frequencies via Labview or whatever software is best suited for the job, as well as modulation parameters,

and have the following things happen:  Assume a working frequency of 150.000 MHz with an FM modulated 1 KHz audio tone modulated at 2.5 KHz deviation

total, with subaudible tone of 127.3 Hz at a deviation of 300 Hz

Receiver test phase: Send instrument control commands to Agilent E4431B signal generator.   Set level to -60 dBm.  Set frequency to 150.000 MHz.  Set

audio tone 1 to 1 KHz and audio tone 2 to 127.3 Hz at a level of 8 pecent of tone 1.  Total deviation not to exceed 2.5 KHz.      Inject test signal into RX port

on radio.

Set R2670B to SINAD function, connected to radio via audio output port. 

Ramp signal level down until SINAD measurement drops to 12 dB. 

Increase signal level to 20 dB quieting.   Measure audio distortion.

Transmitter test phase:   Using appropriate attenuators as needed on spectrum analyzers,  and/or using a switched cabling network,

place radio into transmit using above frequency and modulation specifications.    Set analyzers to receive on the designated frequency

and measure transmitter specifications including measurement of harmonics and spurious emissions.    Measure actual output power

via E4418B power meter.

I'm using two analyzers in order to perform multiple tests in a single transmission. One is optimized for spectral purity tests while

the other analyzes modulation characteristics.    Center frequency, span, and RBW are set as needed. 

When testing a digital radio, the signal chain is slightly different.  The AMIQ I/Q modulation generator's I/Q outputs are fed into the

I/Q inputs on the Agilent generator,  the unit is switched to accept external I/Q inputs,  and the FSEA spectrum analyzer (one of

them) is switched to a preset which sets  up all relevant digital parameters so that it can be used to directly evaluate digital transmissions.

It's not a really elaborate system in planning, but I don't know right now if Labview is all I need or if I'm going to need Teststand or some other

software packages. 

I'll probably want to ask for a few pointers on how to get this configured, later.

[Mr_Johnson]

To clarify,  I want to not just set the instruments to the appropriate frequencies and levels,  etc. but also get data back from them

that allows me to generated a report of all desired and measurable parameter.

I realize this could get a little bit complicated,  but for now I'm only asking for recommendations as to which NI software package(s) are best

suited for controlling this small test system.

[Dennis_Knutson · Accepted solution]

LabVIEW is more than capable of performing this task. It is what it was designed to do. Use Help> Find Instrument Drivers to search for and install drivers that you can use to control and read.

TestStand typically requires the use of a programming language. It manages tests that you write and provides built in features for database logging and report generation whereas you would need to write these modules yourself with just LabVIEW and some add on toolkits. For a single test setup, it might be overkill but it's worth looking at as an addition.

[Mr_Johnson]

Thanks.  Now I need to start in on learning Labview.   At this time I don't even really have a clue as to what the limit of its capabilities are for even a single instrument.

I should probably start out simple,  connecting to a simple instrument like my R&S SMY 02 signal generator and be able to remotely change frequencies, mode, level, modulation depth, etc.

Or even simpler, just start getting measurements out of my Agilent E4418B power meter.   That should be about as simple as it gets.

[johnsold]

Mr_Johnson,

NI has some on-line resources to help you get started learning LabVIEW.  They are a good place to start.

Next check the available drivers.  Some of your instruments probably have drivers already available for download. They can guide you in developing other if necessary.  If the drivers are not available on the NI web site, check with the manufacturers of the instruments to see if they have LV drivers.

Also, be aware that there are some drivers out there which do not follow the best LV programming practices, so do not assume that just because it is publically available code, it is well written code.

Starting simple is also a good idea.  Good LabVIEW practice suggests creating subVIs (modules of code)  and combining them for the overall program.  For example you might have subVIs for initializing (establishing communications), configuring (setting ranges and measurement types), reading data, and closing the communications. The read subVI would go inside a loop so you could take multiple readings without reconfiguring the meter each time.

Lynn

[Mr_Johnson]

Thanks.

I've checked and there are drivers for every instrument that I'll be connecting to.  

At the moment, my level of knowledge about Labview is so low that I just wish that I could load pre-built instrument driver packages up,

have them displayed graphically, connect to the instruments via gpib, and immediately start moving data around. 

I know it's not that simple, but everything gets easier with practice.  I can certainly learn this, too.

[johnsold]

Mr_Johnson,

Also look at the available examples. Under Help choose Find Examples...  While there may not be any for your instruments, there will be some showing how to connect instrument drivers into a complete instrument.

If you really need to get something going quickly, it may be appropriate to consider hiring a LV consultant.  There is a LabVIEW Job Openings Board where you can post your requirements.

LabVIEW is easy to use and easy to program for simple things but a complicated test setup requires a lot of knowledge and experience with both the language and the test process to get a good result.

Lynn, (also Mr. Johnson)