Product Description:

B & R Automation manufactures the X20CM1941, a position-sensor interface in the X20 Fieldbus Input Output Modules series. The unit conditions incremental A/B/Z encoder tracks and resolver signals so that a controller on the fieldbus can read real-time shaft data without extra converters. By occupying one slot on an X20 terminal row, it supports compact axis modules, assembly machines, and packaging lines that need precise feedback to synchronize motion.

The ABR channel provides one output pair and uses a differential A/B/Z topology to resist noise on long cables. Its conversion logic delivers a 14-bit position word, giving 16,384 discrete steps per revolution. Electrical loading on the backplane is minimal because the ABR electronics draw only 0.01 W of bus power, while the auxiliary supply needs 1.5 W for internal signal processing. Incoming pulses are received through an RS422 interface, and the receiver presents an input impedance of 10.4 kΩ – j11.1 kΩ, which matches standard line drivers and helps limit reflections. These parameters help keep timing accuracy stable even when sensors are several meters away.

The resolver side offers one input and drives its excitation with a carrier of 10 kHz at 3.4 Veff. The reference current is limited to 50 mAeff max, and the reference pair is routed as a differential signal to minimize common-mode disturbance. Supported transducers follow the BRX format with a 0.5 ± 10% transformation ratio, allowing interchange with B & R resolver motors. The housing carries an IP20 protection rating, which indicates finger-safe terminals for cabinet installation. This arrangement allows the module to process clean sine and cosine feedback while keeping heat dissipation suitable for the X20 rack.