Our customer would like to configure their own fuel sender with the PV380. Please let me know how to do it. The fuel sender resistance value is as follows:

Empty : 90 +10/-0 ohm
1/2 : 38 ohm
Full : 10 +0/-4　ohm

I also want to know what the resistance range(max/min) that can be configured with PowerVision. This customer currently uses PV101-C and is having an issue with the fuel level reading. The reading fluctuates very frequently(it is too sensitive) because the A/D conversion range is too narrow and the reading is affected by the PWM signal from the PV101 internal heater.

Thank you,

Hello Dai Uematsu,
Thank you for your inquiry. There are several posts on the forum with information about configuring color displays to use resistive senders. This is a good opportunity to provide some information about inputs on the monochrome displays, PV380 in particular. There are a few significant differences.

For monochrome displays, the input readings are in voltage (0-5) or resistance (Ohms). For color displays, the input readings are A/D counts.

The PV380 has three 0-5V inputs and four resistive inputs.

• The PV380 uses a 12bit A/D converter so the voltage resolution will be 5V/4096 =1.22mV. The input circuitry has a gain of 1 so the transfer function is 1:1 however the circuit is unable to drive completely to the min and max values. There is a limit of 35mV at the min and max ends of the range so the measured value does not change until the input reaches .035Vdc and stops changing once it reaches 4.965Vdc. The application automatically converts the incoming signal to a voltage reading so the analog input variable in Powervision will be in units of volts with a 1:1 scale.
  
  The PV380 Resistive Inputs have a 400 ohm pullup to internal 5VDC enabled. The resistance input range is limited from 0 ohms to 6,000 ohms. The variable is locked out at a maximum of 6000 ohms since that is the limit of what can reasonably be measured.
  The scaling is 1:1.
  The resolution is 1 ohm between 0 and 300 ohms then decreases to around 25 ohms at 6,000 ohms. In other words, if the connected resistor is 300 ohms then a 1 ohm change will be detected, if the resistance is 6000 ohms then a resistance change of 25 ohms is required before a change is detected.
  The A/D converter is measuring the voltage ratio of the divider formed between the internal 400 ohm pullup resistor and the resistive input. Since the A/D converter has a resolution of 1.22mV there needs to be enough of a resistance change to change the voltage by 1.22mV. At 6000 ohms a change of 25ohms is required.

For your fuel sensor in PowerVision 2.7, there are two ways to configure a resistive sender on a PV380 in PowerVision.

The easiest way is in the Library tab, there is a tab for Pre-Defined Curves. The other way is with the calculation event on a variable.

I am attaching a very basic config that may be used as an example. I have based the example on the curve data you have listed here, but, the customer will need to do some adjustments for their particular sensor.

• In the example, two resistive inputs have been enabled. Resistive Input 1 uses the Pre-Defined Curve, Fuel Sender. Resistive Input 2 is used as the input for the calculation on the Fuel Level variable.
  Both inputs are created and defined in the IO Definitions.
  The variables and events are in the Programming tab in the Input Output Port Manager group.
  There are gauges to show both input types.

In response to your information about the PV101-C:
The Enovation Controls Technical Services is aware of the problem and is working with engineering to provide a fix. The PV101-C fuel input works best with the recommended fuel sensors. It can work with sensors other than those recommended, perhaps not with the same accuracy. Your customer's issue is well documented and being processed.

Thank you very much for the information and the sample configuration. I will share this with our customer to see if this meets their expectation. If I need any further support, I will post it again.

In regards to the fix on the PV101-C, what kind of change is being worked on by your engineer? Our customer is still using the PV101-C and I am interested in that improvement if available in a short term.

Thank you,

The detailed electrical interface information (ADC bit count, pull-up resistor value, etc.) below is very beneficial. I have searched in the product specs for this kind of detail in the past, but this is the first time I've seen it. Are there specifications available to this detail for the entire PV display product line?

Thanks,
Dan

stalley wrote: There are several posts on the forum with information about configuring color displays to use resistive senders. This is a good opportunity to provide some information about inputs on the monochrome displays, PV380 in particular. There are a few significant differences.

For monochrome displays, the input readings are in voltage (0-5) or resistance (Ohms). For color displays, the input readings are A/D counts.

The PV380 has three 0-5V inputs and four resistive inputs.

• The PV380 uses a 12bit A/D converter so the voltage resolution will be 5V/4096 =1.22mV. The input circuitry has a gain of 1 so the transfer function is 1:1 however the circuit is unable to drive completely to the min and max values. There is a limit of 35mV at the min and max ends of the range so the measured value does not change until the input reaches .035Vdc and stops changing once it reaches 4.965Vdc. The application automatically converts the incoming signal to a voltage reading so the analog input variable in Powervision will be in units of volts with a 1:1 scale.
  
  The PV380 Resistive Inputs have a 400 ohm pullup to internal 5VDC enabled. The resistance input range is limited from 0 ohms to 6,000 ohms. The variable is locked out at a maximum of 6000 ohms since that is the limit of what can reasonably be measured.
  The scaling is 1:1.
  The resolution is 1 ohm between 0 and 300 ohms then decreases to around 25 ohms at 6,000 ohms. In other words, if the connected resistor is 300 ohms then a 1 ohm change will be detected, if the resistance is 6000 ohms then a resistance change of 25 ohms is required before a change is detected.
  The A/D converter is measuring the voltage ratio of the divider formed between the internal 400 ohm pullup resistor and the resistive input. Since the A/D converter has a resolution of 1.22mV there needs to be enough of a resistance change to change the voltage by 1.22mV. At 6000 ohms a change of 25ohms is required.

For your fuel sensor in PowerVision 2.7, there are two ways to configure a resistive sender on a PV380 in PowerVision.

The easiest way is in the Library tab, there is a tab for Pre-Defined Curves. The other way is with the calculation event on a variable.

Hi Dan,

If you had all of that information, what kind of fun would you get to have?

The source of this information is our friendly Tech Services Support, http://www.fwmurphy.com/resources-suppo ... al-support. They have the best details, electrical specs, for the different displays/controllers.

Mostly on the forum here, we deal with PowerVision Configuration Studio and leave the electical specifications to the Applications engineers and Tech Services. They have all helped me to provide the information that is sometimes requested here. I was kinda showing off with the PV380 information I happened to have.

We have the best information here about how to program your PV380 resistive input for a fuel sender.

When the 2.8 PowerVision gets released, we have added a reference manual just to address the I/O, it has more details, but still doesn't have the electrical specifications.

So, long way to say the best source for display/controller electrical specs is Technical Services.