broken wire

[GerdW]

Hi cantata,

why do you need to compare loop count with max number of iterations in a FOR loop?

And your description yells for "use a 2nd loop"!

[Dennis_Knutson]

You aren't doing any of that. You are using the same frequency for each of the 48 iterations of the loop. There does not appear to be any need for the comparison or the case statement. You are doing what appears to be a sweep and not fine tuning. If you want to do a sweep on consecutive channels, use a for loop around the code so that after the first sweep, you change the channel and the inner for loop would be executed again.

[altenbach]

You are not stepping any inputs to the subVI, in fact the FOR loop will complete as fast as the computer allows.

What is happening inside the subVI (FTF)? Is that one interactive or is it just a formatting operation?

Why would the result of your division ever be equal to the interation terminal and why would that matter? What is deciding which case of the case structure should execute?

[cantata2014]

Yes I want to sweep the frequency. I want to sweep by fine tuning the frequency.

the laser has multiple channels, and we can set the Grid Spacing between channels, the default value of Grid is 50GHz, I want to sweep every 0.1GHz,  I don't know if I can set the Grid to that small, so I wanted to use FineTuneFrequency (the maximum of FTF is 6GHz)

for example, choose channel1 first (frequency =100GHz), then fine tune by 0.1GHz, frequency=100.1GHz.  fine tune 0.1 again, frequency=100.2GHz..........loop for 10 times , frequency=101GHz. then jump to channel 2 (frequency of channel2=101GHz), then loop the FTF for 10 times.....then jump to channel3.....

so I want to use for loop to fine tune for 48 times, and jump to a new channel.....maybe the configuration I draw is wrong........could you tell me how to correct it ? Thanks!

[cantata2014]

the input is FTF (FineTuneFrequency), and the subVI (FTF) is just a formatting operation.

I want to sweep the frequency. and when it executes for N times, the laser jump to a new channel. then tune the frequency for N times again...

[GerdW]

Hi cantata,

just a "concept drawing" from your descriptions:

[cantata2014]

another simple question: 

broken wire: the type of the source is 1-D array of VISA session of class, the type of the sink is VISA session of class.

How can I connect them together??? Thanks!

[Dennis_Knutson]

Don't create an array of VISA sessions. Do you have something in a for loop and auto-indexing an output? Don't do that.

[cantata2014]

I just want to close the VISA session. and in the for loop there is a channel sweep

[GerdW]

As Dennis said:

DON'T create an array of VISA references!

If you don't know how to handle the situation until now I suggest going through the LabVIEW basics (free online courses offered by NI) and read the full help on the FOR loop!

(Or use the current LabVIEW version 2014 as it will help in exactly this situation. It was a nice webcast yesterday…)