I/O Modules - Sensors - Problem with temperature readings

Issue

Temperature readings from I/O modules are not consistent and the values are fluctuating.

Possible causes and solutions

1. Check if the wiring between the module and sensor is correctly connected.

2. Check if the problem persists if the sensor is connected to another input.

3. Check if there are no device interfering communication.

4. Parallel connect a 200 Ohm resistor.

5. Check the sensor’s instruction for correct power supply and grounding guidelines.

6. Appropriately set the input filtering time. Due to the high speed of AC signals, inputs may not correctly read lower frequency signals, such as 50 Hz. Filters ensure a more stable reading of these signals, eliminating erroneous readings.

7. Check if a correct sensor type has been selected in the iSMA Configurator.

   

8. If Niagara 4.12 is used:

   • Update it to the latest 4.12 version or version other than 4.12;

   • If it is not possible to change the version, use the following configuration for points where the temperature is negative: Conversion = linear, Offset = -655.36. If this configuration is used together with a positive temperature, an error will occur.