Digital Input details

In page 2.2 of manual 41110485 it shows some details on the digital input possible on pins 1,2&3 of the power connector but i’m missing some details.

  1. What is the maximum open voltage if the digital input is enabled but the circuit is open like in diagram 2-20? Table 2-2 shows Vin for Maximum. Can I assume that that is equal to the input voltage from the external supply powering the gateway? If the gateway is powered by 24V DC supply for example, will the digital input pin be 24V if the circuit is open?
  2. The way I interpret table 2-2, it says that “open” state is any voltage between zero and 1V and “closed” is any voltage above 3V. Is that correct?

The application is a simple oil level float style switch that opens or closes depending on the oil level.