Product Description:

The S20-AI-4-U is an I/O expansion module produced by Bosch Rexroth Indramat for the S20 IndraControl Modules series. Intended for voltage-based sensing, it transfers raw field signals to the controller through the internal bus, where they are digitized and scaled for process control. The slice-format module mates directly with other S20 stations, so machine builders can extend measurement capacity without redesigning wiring harnesses. Because it relays live process values to the automation system, the module supports closed-loop regulation, alarm monitoring, and detailed data logging across manufacturing cells. Its compact format also allows additional measurement channels to be installed within an existing S20 station while minimizing the amount of cabinet space required.

The incoming conductors should use shielded twisted-pair cabling; the continuous shield and differential geometry reduce electromagnetic pickup that can distort low-level readings. Each channel accepts voltage signals, so transducers that provide 0–10 V or ±10 V outputs can connect directly without external signal conditioning. Data is transferred through a bus base module that distributes power and serial communication lines along the S20 stack. When the installation cabinet provides at least IP54 protection, the electronics remain protected from dust and splashing water that could interfere with operation. The assembly functions as an analog input device, so its circuitry performs analog-to-digital conversion and reference scaling rather than supplying output signals. This arrangement allows the controller to receive measured values from several common industrial sensors through a centralized I/O station.

The housing clips onto a DIN rail, allowing it to be removed or repositioned without tools during maintenance. Internally, the board provides four independent measurement paths, enabling a single module to monitor multiple sensors while keeping channel crosstalk low. Although the surrounding enclosure must meet the required sealing level, the module itself carries an IP20 rating, indicating finger-safe terminals without a built-in protective gasket. All control and supply lines pass through the S20 backplane, so the module does not require a separate power connector. Diagnostic LEDs on the front provide a visible indication of channel status and help users identify signal or connection problems. The removable mounting arrangement also provides direct access to neighboring modules when the I/O station is inspected or rearranged.