Siemens 505-6851B Remote Base Controller Module

Siemens 505-6851B Remote Base Controller Module is a Remote Base Controller (RBC) for the TI505 family that links a remote I/O base to the central TI505/Siemens controller over RS-485. The B variant uses a rotary base-address switch for selecting the remote base number and includes status displays with codes, RS-232 and I/O ports, and a modem F-connector for optional remote communications. Addresses on the RBC are defined with hexadecimal values A–F (10–15), reflecting the distinction between 505-6851A and 505-6851B in the address selector. As part of the 505/545/555/575 system family, the 505-6851B is designed to work with 505-series CPUs and I/O bases to distribute modules across a plant floor, making it suitable for remote I/O installations in manufacturing or process control.