Some confusion may occur when determining whether a field device (transmitter) is 2, 3 or 4 wire because of the number of wires/conductors in an M12 cordset, however, it is not the number of wires/conductors in a cordset that determines 2, 3, or 4 wire functionality.
2, 3, or 4 wire functionality is determined by the minimum number of wires/conductors required for 4-20mA functionality (by industry norm terminology).
A cordset may have more wires/conductors than are needed for 4-20mA functionality for other functions, but those conductors do not count when determining 4-20mA functionality.