How to Automatically Increase Frequency and Amplitude of Anritsu MG3694A Over GPIB?

[wyattmengy]

Hello everyone!  

I just started playing with LabView a few days ago and my knowledge to it is very juvenile .

I'm currently setting up equipments for measuring some microwave chips we prototyped at school.  The equipments include two Anritsu MG3694A signal generators, one Agilest E3631A DC power supply, and one Agilest E4446A spectrum analyzer.  

I'm trying to conduct a two tone test by using that two MG3694A sig-gens.  More specifically, for each of the sig-gen, I'd like to program LabView in a way that it does a "2D frequency and amplitude sweep".  This means that LabView will start at one frequency (Fmin) and one amplitude (Amin), once MG3695A sweep all the way to the Fmax, LabView will ask the sig-gen to come back to initial frequency, and in the same time increase the amplitude by a specific step size, sweep from Fmin to Fmax again.  Perform this iteration until it reached both Fmax and Amax.

I have figured out how to perform frequency sweep and adjust amplitude manually, but I have no idea yet how to program LabView so that it automatically reset the frequency from Fmax back to Fmin and increase amplitude by the step size.  What VI or function palate should I use?  Can anybody give some insight?

[Luke_W]

Hey wyattmengy.

                        As with most programming languages, there are a number of different ways to accomplish this task. Elements that you may find particularly useful would be the Select.vi and shift registers integrated in a while loop. The Select.vi takes an input of a true or false boolean (in your case an "equal?" comparison that you will set to the maximum frequency) and wires through one of two results depending on the value of the boolean. Shift registers are feedback loops that can be added by right clicking the left or right frame of a while loop. They function to return the ending value of the while loop back to the beginning for the next iteration. You might want to use this as your frequency increment. 

I've attached a snippet of code that will increment a value until the maximum is reached and then reset back to 1. The principle behind it should be useful in implementing your frequency sweeps.

Hope this helps,

Luke W