Where has interpolate gone?

Discuss issues and ideas you have to configuring displays with PowerVision
vtaylor
Posts: 13
Joined: Fri Jul 27, 2012 7:33 am

Where has interpolate gone?

Post by vtaylor » Wed Oct 08, 2014 2:48 pm

I'm working in PV 2.7.10439 with a P480 and I need to set up an interpolated curve, but when I go to the pre-defined curves section I find that there is no option to interpolate anymore. Polynomial fitting isn't going to work for this one - is there a way to get the interpolation option back?
Last edited by vtaylor on Wed Oct 08, 2014 3:29 pm, edited 1 time in total.
vtaylor
Posts: 13
Joined: Fri Jul 27, 2012 7:33 am

Re: Where has interpolate gone?

Post by vtaylor » Wed Oct 08, 2014 3:29 pm

Another question - in working with and analog input on a PV480 display configured as 0-5V voltage input I'm seeing some very strange results. When I just show a raw number (no scaling curve or anything) using a text gauge I see that the voltage reported is ~5x the actual input voltage on the pin. When I try to apply a scaling curve that accounts for the 5x multiplier it gets really weird, saturating my curve at less than 0.5V. What happened to the handling of the analog inputs? Am I just doing it wrong? I've used the analog inputs on the PV380 in 2.7 without any problems, is it different for the PV480?
stalley
Enovation Controls Development
Enovation Controls Development
Posts: 618
Joined: Tue Mar 18, 2014 12:57 pm

Re: Where has interpolate gone?

Post by stalley » Thu Oct 09, 2014 8:15 am

Hi vtaylor,

Monochrome displays are rather different from color displays when it comes to inputs.

On color displays, the input values are counts. On monochrome displays, the input values are Ohms, Volts or mAmps depending on the input.

Unfortunately, on the color displays there is not the Interpolate option for pre-defined curves. It has to be done with a script. At least with color displays you have scripting, on a monochrome display it would have to be done in expressions on calculation events.

I assume that your sender is resistive or you have an unusual 0-5V/4-20mA input.

I am attaching an example of a script that does interpolation for a Murphy fuel sender. Hopefully this can save you a little time. I took it out of a 2.6 config, I haven't compiled it, so be sure to use the Compile All Scripts button before you use it. (Speaking from experience).
Fuel Sender script.txt
Interpolation Example Script
(1.13 KiB) Downloaded 38 times
Sara Talley
Software Engineer
Enovation Controls
vtaylor
Posts: 13
Joined: Fri Jul 27, 2012 7:33 am

Re: Where has interpolate gone?

Post by vtaylor » Thu Oct 09, 2014 10:44 am

Thanks Sara,

We have been using the interpolation scripts on these voltage senders since the early 2.3 versions of PowerVision so that works great for us. I haven't had to touch the PV480 analog voltage inputs in quite a while (obviously) and my understanding has apparently been polluted by my recent (and quite extensive) sojourn in the land of monochrome displays. I appreciate you clearing that up for us, now I know how to proceed and will get things going!

-Virgil