Frequency output of PV780

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toni27
Posts: 11
Joined: Thu Nov 28, 2013 6:24 am

Frequency output of PV780

Post by toni27 » Thu Oct 30, 2014 8:09 am

Hello,

how can I manage to set up a frequency at the frequency output port of the PV780?
I tried several ways to get an output at all, but to no effect.

Thanks,
Toni
stalley
Enovation Controls Development
Enovation Controls Development
Posts: 618
Joined: Tue Mar 18, 2014 12:57 pm

Re: Frequency output of PV780

Post by stalley » Thu Oct 30, 2014 9:22 am

Hello Toni,

There is some very basic information about the frequency output in the PowerVision Configuration Studio Applications Reference Manual under the Input Output Port Manager.

The quick and easy way is to go to the Connections tab and select the Frequency Output. Check the Auto Create box. This gives you a variable associated with the Frequency Output.

Now, go to the Programming tab, your new variable should be in the Input Output Port Manager group. You will need to set this to the appropriate rate for your system, the units are Herz. You can set the variable just like any other variable, programmatically or if you uncheck the Allow Invalid, you can set a default value.

You will need to add an event with the action, Input Output Port Manager (IO) > Frequency Update(Your Frequency Variable).

Firing this event should change the output rate to the value you have set your frequency variable to be.

If you are wired up appropriately, you should see the output as soon as you fire the event.

If this isn't working for you, let us know and we can go from there.
Sara Talley
Software Engineer
Enovation Controls
toni27
Posts: 11
Joined: Thu Nov 28, 2013 6:24 am

Re: Frequency output of PV780

Post by toni27 » Mon Nov 17, 2014 6:49 am

Thank you, it works now.
JoakimMD
Posts: 20
Joined: Fri Oct 22, 2010 9:17 am

Re: Frequency output of PV780

Post by JoakimMD » Wed Apr 01, 2015 7:37 am

Hi,

Putting my question here instead of making a new thread.

I am also using the frequency output but I think it is not so accurate. For example, if i put 2920 Hz on the output I measure 2757 Hz with an oscilloscope. Can you guys tell me how accurate the output should be? Also if I step the frequency up it will get stuck for a while and then jump up in frequency.

Se my table of my measurements. First column: My F variable, Second column: What I measure.
Pretty stange, isn´t it!

1000 997,2
1030 1019
1060 1042
1120 1116
1240 1234
1480 1465
1960 1953
2920 2757
4840 4687
5080 4687
5320 5208
5800 5208
6760 6697
7000 6697
7240 6697
7720 6697
7960 7812
8200 7812
8440 7812
bmcrae
Enovation Controls Development
Enovation Controls Development
Posts: 75
Joined: Thu Sep 09, 2010 11:20 am

Re: Frequency output of PV780

Post by bmcrae » Wed Apr 01, 2015 8:34 am

That is what we measured in software test as well. The frequency out gets more inaccurate as you go higher in frequency. Unfortunately that is the accuracy you can expect from this output.

Thanks,

Brian McRae
Enovation Controls
bmcrae
Enovation Controls Development
Enovation Controls Development
Posts: 75
Joined: Thu Sep 09, 2010 11:20 am

Re: Frequency output of PV780

Post by bmcrae » Wed Apr 01, 2015 8:38 am

Also we only claim accuracy up to 3000. The main purpose of this output was for tachometer, this worked for those gauges, but the trade off was more inaccurate at higher ranges.

Brian McRae
JoakimMD
Posts: 20
Joined: Fri Oct 22, 2010 9:17 am

Re: Frequency output of PV780

Post by JoakimMD » Thu Apr 02, 2015 1:55 am

Thanks! Ok, as long as you know its limitations. To say you have a 10 kHz frequency output is a bit misleading when the ONLY frequency you can output above 3 kHz is: 3125, 3348, 3805, 4262, 4688, 5208, 5860, 6697, 7812 and 9375 Hz.

Yes folks, its increasing in steps like this. Its not variable. I have gone through every single frequencey from 680 Hz up to 10 kHz and its only 64 steps.

What is the purpose with this output? Because my intended use is not doable.

/Joakim
stalley
Enovation Controls Development
Enovation Controls Development
Posts: 618
Joined: Tue Mar 18, 2014 12:57 pm

Re: Frequency output of PV780

Post by stalley » Thu Apr 02, 2015 8:50 am

Hello JoakimMD,

The literature is confusing for the PV780 frequency output. I apologize. In a wiring section, it shows 0-10kHz, but in the rest of the literature, it shows, 2Hz-3kHz, Vbat rms square wave for the frequency output. The installation manual shows the frequency output going to a tachometer which is the intended use for the output.

I have notified marketing about the inconsistency.
Sara Talley
Software Engineer
Enovation Controls