A cap for a two-wire fluid sensor (202, 326), the cap comprising: a cap input port including a first toolless connector configured to removably couple to a connector of a first cable (218, 318, 504); a cap output port including a second toolless connector configured to removably couple to a connector of a second cable (218, 318, 504); and a two-wire interface circuit (320, 620) including a circuit input port coupled to the cap input port and a circuit output port coupled to the cap output port, wherein the first toolless connector is configured to removably couple the circuit input port to the connector of the first cable (218, 318, 504) and the second toolless connector is configured to removably couple the circuit output port to the connector of the second cable (218, 318, 418, 504), wherein the two-wire interface circuit (320, 420, 620) includes a sensor port (332, 622), wherein the circuit input port includes a ground terminal and a plurality of sensor signal input terminals, each of the sensor signal input terminals having an input ordinal value, the circuit output port includes a ground terminal and a plurality of sensor signal output terminals, each of the sensor signal output terminals having an output ordinal value, the sensor port (332, 622) includes a ground terminal for a ground and a sensor signal terminal for a sensor signal, the two-wire interface circuit coupling the ground terminal of the sensor port to the ground terminal of the circuit output port and to the ground terminal of the circuit input port and coupling the sensor signal terminal of the sensor port to a first one of the plurality of sensor signal terminals of the output port, wherein the two-wire interface circuit further comprises a plurality of cross-connections coupling each of the plurality of sensor signal output terminals to a corresponding one of the plurality of sensor signal input terminals, and each of the plurality of sensor signal output terminals has an output ordinal value that is one greater than the input ordinal value of the corresponding one of the plurality of sensor signal input terminals. a cap input port including a first toolless connector configured to removably couple to a connector of a first cable (218, 318, 504); a cap output port including a second toolless connector configured to removably couple to a connector of a second cable (218, 318, 504); and a two-wire interface circuit (320, 620) including a circuit input port coupled to the cap input port and a circuit output port coupled to the cap output port, wherein the first toolless connector is configured to removably couple the circuit input port to the connector of the first cable (218, 318, 504) and the second toolless connector is configured to removably couple the circuit output port to the connector of the second cable (218, 318, 418, 504), wherein the two-wire interface circuit (320, 420, 620) includes a sensor port (332, 622), wherein the circuit input port includes a ground terminal and a plurality of sensor signal input terminals, each of the sensor signal input terminals having an input ordinal value, the circuit output port includes a ground terminal and a plurality of sensor signal output terminals, each of the sensor signal output terminals having an output ordinal value, the sensor port (332, 622) includes a ground terminal for a ground and a sensor signal terminal for a sensor signal, the two-wire interface circuit coupling the ground terminal of the sensor port to the ground terminal of the circuit output port and to the ground terminal of the circuit input port and coupling the sensor signal terminal of the sensor port to a first one of the plurality of sensor signal terminals of the output port, wherein the two-wire interface circuit further comprises a plurality of cross-connections coupling each of the plurality of sensor signal output terminals to a corresponding one of the plurality of sensor signal input terminals, and each of the plurality of sensor signal output terminals has an output ordinal value that is one greater than the input ordinal value of the corresponding one of the plurality of sensor signal input terminals.