#233 Arduino PLC IDE: Opta Analog Expansion RTD input causes SOURCE NOT OK / PLC NOT RUNNING

[Simon]

PC:

• Windows 11 Pro 24H2 64-bit

Software:

• Arduino PLC IDE 1.1.0
• Arduino IDE 2.3.10

Target:

• Finder Opta Advanced
• Finder Analog Expansion A0602

PLC Runtime:

• 1.34.2

Target System:

• 1.3.2 ArduinoOpta

Expansion firmware:

• Latest available (updated using Arduino IDE)

Problem:
When I1 is configured as "Input - Voltage ADC", the PLC runs normally.

When I1 is configured as "Input - RTD 2 wires" or "Input - RTD 3 wires", the project compiles and downloads successfully, but immediately enters SOURCE NOT OK / NOT RUNNING.

The same PT100 sensor and expansion work correctly using the Arduino IDE example:
Arduino_Opta_Blueprint -> Analog -> RTD

The example continuously reads approximately 109.86 Ω, proving the hardware, wiring and firmware are working.