Host Engineering Forum

General Category => Do-more CPUs and Do-more Designer Software => Topic started by: RBPLC on August 21, 2020, 03:28:35 PM

Title: Odd-Ball Thermistor
Post by: RBPLC on August 21, 2020, 03:28:35 PM
I have an application using a "non-listed" (not available in the thermistor list in temperature card) PTC thermistor that I'm tryin to use with a BX-08UT. I have the resistance curve for this thermistor. Is there any way to get a generic resistance reading with this card to which I can apply my own interpolation curve? It would be nice to include a non-linearized (raw) option that could be used for a "non-standard" thermistor.   
Title: Re: Odd-Ball Thermistor
Post by: BobO on August 21, 2020, 04:18:40 PM
I have an application using a "non-listed" (not available in the thermistor list in temperature card) PTC thermistor that I'm tryin to use with a BX-08UT. I have the resistance curve for this thermistor. Is there any way to get a generic resistance reading with this card to which I can apply my own interpolation curve? It would be nice to include a non-linearized (raw) option that could be used for a "non-standard" thermistor.

Sorry, no. You might pick the next higher resistance, and use a LERP to convert the reported values to the actual. Not sure how well it work, but I'd certainly try it.
Title: Re: Odd-Ball Thermistor
Post by: RBPLC on August 21, 2020, 04:25:17 PM
Would the generic thermistor with no linearization be an easy add?
Title: Re: Odd-Ball Thermistor
Post by: BobO on August 21, 2020, 04:40:58 PM
Would the generic thermistor with no linearization be an easy add?

If the temperature chip supports it at all (unknown) it would require changing the firmware in the module, which isn't field upgradable. At best, it's quite a bit of work.
Title: Re: Odd-Ball Thermistor
Post by: ADC Product Engineer on August 22, 2020, 05:29:45 PM
When I talked with the design engineer before the module was launched it looked like a ton of work to make this happen.  Just not enough ROI to justify the amount of effort it would take.
Title: Re: Odd-Ball Thermistor
Post by: Controls Guy on August 22, 2020, 07:48:36 PM
Should be easy to derive the transfer function for the readings from a similar type, set the module up for that, and scale in ladder.