When a data parameter cannot be calculated properly, the RDE300 may read "NAN" for this parameter via the RDE300 Engineering Client or via the unit's Modbus registers.
Some situations that can result in a NAN value are described below.
Number | Issue | Possible Causes |
1 | Instantaneous Soiling Ratio = NAN | As explained in the RDE300 Series User Guide, instantaneous values for soiling ratio parameters are only calculated and reported during specific conditions of irradiance and time. These are intermediate values and should be ignored by the user except for troubleshooting. For final results of Soiling Ratio, please use the values labeled Daily Average.
Instantaneous values of Soiling Ratio may read NAN in the following conditions: - Irradiance is not within required range selected in configuration (typically >500 W/m2 required). See user manual. Use Daily Average value.
- Time is not within time window selected in configuration (typically local noon +/- 2 hours). See user manual. Use Daily Average value.
- Temperature sensor is disconnected or not functioning. Valid temperature readings are required. Correct the temperature sensor.
- Module calibration data missing or incorrect
- Readings are out of range
|
2 | Daily Average Soiling Ratio = NAN | - The unit has just been installed. Daily soiling ratio is calculated at the end of the soiling ratio time window for each day. See user guide.
- An average could not be calculated for the previous day due to low or unstable irradiance, usually due to cloudy weather.
- Temperature sensor is disconnected or not functioning. Valid temperature readings are required.
- Module calibration data missing or incorrect
|
3 | Temperature = NAN | - Temperature sensor disconnected or not functioning
- Temperature reading out of range
- Temperature sensor selection configured incorrectly
|
4 | Isc, Pmax, or Voc = NAN | - IV sweeps are disabled
- IV sweeps are not supported for your model number
- Sweep fit returned results out of range
- Temperature sensor is disconnected or not functioning
|
5 | Isc, Pmax, or Voc = 0 | - Irradiance is too low to extract fits from IV curve
|
For guidance or troubleshooting help, contact us.
