ifm has expanded its RM900S safety encoder family for mobile machines, adding certified options for measuring position, angle, and speed where vehicles, superstructures, and moving elements operate automatically.
The encoders are designed for applications including municipal vehicles, automated guided vehicles, intralogistics systems, heavy-duty autonomous mobile robots, mining machines, harbour equipment, cranes, lifting structures, axles, tipping skips, and other mobile assemblies where reliable motion data is part of safe operation.
The RM900S family records movement so machine builders can derive steering, turning, tilting, and lifting values. Its “preset on the fly” function enables continuous position synchronisation during motion, for example through RFID, allowing accuracy to be maintained without stopping the machine or interrupting the operating cycle.
Each encoder includes built-in sensor redundancy and continuous self-monitoring of safe operation, both tested and certified by TÜV Rheinland. The range supports CANopen and CANopen Safety, operates from 8 to 36V DC, offers 29-bit resolution, carries an IP69K protection rating, and meets SIL2 and PLd safety levels. A multicolour LED on the rear of the housing gives a direct indication of safe operating status.
The expanded family includes axial and radial connection variants with solid or hollow shafts. New additions include a direct hollow shaft flange version without stator coupling and a servo flange version for external couplings or cable pulls. CAN input and output are included on each encoder, allowing several encoders or compatible sensors to be connected in series through daisy chaining.
That installation approach is useful on larger mobile systems, where sensing points may be distributed across steering systems, lifting arms, rotating assemblies, articulated joints, and attachments. Reducing cable complexity, commissioning time, and software work can help machine builders shorten development cycles while maintaining safety documentation.
The encoders are also integrated into the SISTEMA library, reducing the work needed to implement and verify safety-related automation functions. When paired with an ifm controller, the products are intended to reduce programming effort in Codesys because secure communication between the controller and encoder is supported by default.
Mobile machinery is becoming more automated while operating in harsher and less predictable conditions than many factory systems. Vehicles and plant must deal with vibration, moisture, dust, shock, temperature variation, uneven loads, outdoor exposure, and proximity to people. Safety sensors in those settings cannot be delicate accessories; they need to be designed into the machine’s safety architecture from the beginning.
The growth of AGVs, AMRs, automated yard equipment, and semi-autonomous mobile plant is increasing the need for safety-rated feedback. Machines that previously relied heavily on operator judgement are increasingly expected to monitor their own movement, enforce limits, prevent unsafe positions, and communicate status to controllers. Accurate position and speed information becomes a safety function rather than a simple control input.
Mobile robotics also places pressure on system design because several safety technologies must work together. Encoders, lidar, cameras, ultrasonic sensors, inertial measurement units, controllers, brakes, and software all contribute to how a machine understands position and reacts to risk. A certified encoder can strengthen that system by giving the controller trusted information about movement and orientation.
Machine acceptance often depends on reducing uncertainty. Safety certification can be time-consuming, especially where equipment works near people or carries heavy moving structures. Components that combine redundancy, self-monitoring, defined communication, and library support can help machine builders move through validation with fewer gaps.
ifm’s expanded RM900S range reflects the broader movement toward safer, more autonomous, and more data-rich mobile equipment. As automated movement spreads through logistics, construction, municipal operations, mining, ports, and factories, every moving element needs to be brought into a known, monitored, and controlled position.
