Connection method: CoE 0x08n0:1A "Connection Technology"

2-, 3- or 4-wire connection of the sensor can be selected here depending on the terminal type. Basically, the lowest measurement uncertainty (colloquially: lowest measuring error) can be achieved with a 4-wire connection (if available), since supply line resistances are actively deducted.
With "not connected" (if present) the respective channel is completely disabled, the conversion time of the EL32xx is shortened accordingly.

The number of connection wires of the sensor and the terminal setting in CoE 0x80n0:1A should match! This is the only way to assure that the capabilities of the sensor and measuring device are used in the best possible way. Otherwise you have to work with wire jumpers (sensor has less lines than are possible in the measuring device) or double assignment (sensor has more lines than are possible in the measuring device). This increases the measurement uncertainty. Here are a few (bad) examples:

• 4-wire sensor and 2-wire terminal:
  The added value of the 4-wire sense measurement cannot be exploited, the complex 4-wire sensor is operated as an uncompensated 2-wire sensor, either the sense lines of the RTD are not connected at all or are also plugged into the 2-wire contacts.
• 2-wire sensor and 4-wire terminal:
  External wire jumpers must be plugged into the terminal to trick the terminal into believing that it is a 4-wire sensor, the 4-wire capability of the terminal cannot be exploited.