The Mitsubishi RJ71GN11-T2 is a PLC expansion module in the MELSEC iQ-R series, catalogued as a PLC Expansion Module under PLCs and Accessories.
What it does in the rack
As an iQ-R expansion module, the RJ71GN11-T2 mounts to the right of the CPU/base unit on the same DIN segment and is addressed as a slot in the GX Works3 I/O assignment table, so the commissioning step is configuration rather than rewiring. Before energising, confirm the slot number and station number in GX Works3 match the module's rotary switches — a mismatch is the usual cause of a 'module not detected' fault at first power-up on iQ-R builds.