FANUC A02B-0303-C205 is a basic four-axis separate detector interface unit, commonly called SDU1, for compatible FANUC CNC servo systems. It connects external position detectors such as linear scales to the CNC through the FSSB optical servo network.

The unit provides four detector channels through JF101–JF104 and supports an additional four-axis unit when required. Use the complete A02B-0303-C205 nameplate as the primary reference and confirm the detector type, FSSB layout, connectors and CNC parameters.

A02B-0303-C205 Product Specifications

Four-Axis Position Feedback Interface

The A02B-0303-C205 receives feedback from up to four separate position detectors, including compatible linear scales for full-closed-loop axis control. FSSB links the interface unit with the servo system and CNC. OPEN indicates FSSB communication; ERR1 and ERR2 indicate disconnection at the rear- or front-stage optical interface.

Basic Unit vs. Additional Unit

A02B-0303-C205 is the basic four-axis unit. FANUC lists A02B-0236-C204 as the additional four-axis unit, connected through CNF1 when more detector channels are required. They have different roles and are not identical replacements. Confirm the system architecture and connector assignments.

Testing and Installation Notes

REACO CNC checks the nameplate, housing, detector connectors, FSSB ports, power circuit, battery interface, LEDs and communication before shipment. Isolate power, protect optical connectors from contamination, and record the FSSB order and detector settings before removing the original unit.

Related resources: FANUC interface and I/O units and FANUC CNC repair services.