Ratiometric option for PhidgetInterfaceKit in Flowstone

For general discussion related FlowStone
Post Reply
pars11
Posts: 6
Joined: Thu Oct 17, 2013 2:38 pm

Ratiometric option for PhidgetInterfaceKit in Flowstone

Post by pars11 »

I have Phidget Interface Kit,voltage and current sensors. voltage sensor is nonratiometric and current sensor is ratiometric. In phidgets API you can enable or disable ratiometric option but I didnt see this ability in Flowstone or I dont know. Do u know how could I enable or disable ratiometric option for InterfaceKit through Flowstone.

Thanks
User avatar
trogluddite
Posts: 1730
Joined: Fri Oct 22, 2010 12:46 am
Location: Yorkshire, UK

Re: Ratiometric option for PhidgetInterfaceKit in Flowstone

Post by trogluddite »

Hi Pars,
I assume you are using one of the sensors that connects to the regular phidgets interfaces. Which model exactly are you using? I noticed on the Phidgets support pages (for example this one), that they have equations there for transforming raw sensor values into actual voltage and current values. My guess is that the 'ratiometric' setting in the API is applying exactly these equations - so it should be possible to build a small maths module to take the values from the Phidgets primitives in FS and do the same transformation.
All schematics/modules I post are free for all to use - but a credit is always polite!
Don't stagnate, mutate to create!
pars11
Posts: 6
Joined: Thu Oct 17, 2013 2:38 pm

Re: Ratiometric option for PhidgetInterfaceKit in Flowstone

Post by pars11 »

I am using PhidgetInterfaceKit 8/8/8. Unfortunately that method is not working because sensor digital value is changing according to ratiometric and nonratiometric option. I did try calibration and if I choose nonratiometric option when I was calibrating it, It is impossible to calibrate it, it is giving different value every time. Same thing happens for ratiometric option chosen for non-ratiometric devices.
This is how we calibrate sensors http://w3.tue.nl/fileadmin/id/objects/E ... ensors.pdf

In the Phidgets website,it shows that getratiometric and setratiometric APIs but I dont know how can I apply it to Flowstone
Post Reply