Method for Determining Sensor Types and Sensor Wiring

A system for determining the type of an analog sensor device in a process control system comprising at least a terminal block unit comprising four connection ports connectable with an analog sensor device, wherein the sensor device to be determined is a 2-wire connection sensor device, a 3-wire connection sensor device, or a 4-wire connection sensor device, comprising:

• a) a detection unit configured to detect whether a predefined resistance value is present for a 2-wire connection sensor device at the connection ports of the terminal block unit provided for the 2-wire connection sensor device;
• b) a detection unit configured to further detect whether a predefined resistance value is present for a 3-wire connection sensor device at the connection ports of the terminal block unit provided for the 3-wire connection sensor device, in case, a predefined resistance value for a 2-wire connection sensor is detected in step a);
• c) a determination unit configured to determine that a 2-wire connection sensor device is connected to the terminal block unit, in case, no predefined resistance value for a 3-wire connection sensor device is detected in step b);
• a detection unit configured to further detect whether a predefined resistance value between two predefined pairs of connection ports of the terminal block unit is provided, in case, a predefined resistance value for a 3-wire connection sensor device is detected in step b);
• d) a determination unit configured to determine that a 3-wire connection sensor device is connected to the terminal block unit, in case, only between one of the two predefined pairs of connection ports of the terminal block unit a predefined resistance value is detected in step c);
• and
• a determination unit configured to determine that a 4-wire connection sensor device is connected to the terminal block unit, in case, between two of the two predefined pairs of connection ports of the terminal block unit a predefined resistance value is detected in step c).