Product Description:

The S20-AI-4-RTD is an analog input module manufactured by Bosch Rexroth Indramat for the S20 IndraControl Modules series. Mounted alongside other S20 nodes, it accepts resistance temperature detector signals and forwards converted process values to the controller through the station backplane. The module supports distributed temperature acquisition in packaging machines, process skids, and general factory automation where accurate thermal feedback is required for closed-loop regulation and diagnostics.

Integration into an S20 station is handled through the S20 Local Bus, which moves data between the electronics section and the head module at backplane speed. Field wiring uses a shielded twisted pair to minimize noise in low-level sensor circuits, and each conductor uses the push-in connection method for tool-free installation. The housing is molded from self-extinguishing V0 plastic and finished in the functional color Pale Green RAL 6021, making analog input points easy to distinguish. Internally, the module uses a bus base and electronics assembly, while the removable terminal strip has a spring-cage profile for resistance to vibration. When mounted on a DIN rail, the enclosure provides IP20 ingress protection and meets overvoltage category II requirements for low-energy control circuits. A single node can accommodate up to 63 modules before reaching the bus timing limit.

The module remains functional at installation altitudes up to 3000 m, allowing operation in high-altitude facilities without derating. Power for the analog circuitry is supplied through the backplane on the dedicated UA (UAnalog) rail, which keeps sensor excitation separate from the logic voltage and helps reduce common-mode errors. The device has protection class III, so it relies on the extra-low-voltage SELV supply of the overall control system rather than a protective earth conductor. This power arrangement also avoids the need for a separate field supply connection to the module’s analog electronics.