The PLC 1785-BCM is a legacy communication module that is used with the PLC5 controller platform. This module is a single-slot chassis that is used to provide communication redundancy and switchover capability from a primary PLC processor to a stand-by PLC5 processor. This module is able to provide high-speed Data Highway Plus (DH+) and Remote I/O (RIO) communication backup via the high-speed serial link (HSSL) with switchover speed up to 1.2 Megabaud.
The 1785-BCM also features an internal buffer amounting up to 4K Words and capable of initiating switchover in different events such as power failure, processor error including 1785-BCM partner module fault. Additionally, switchover may also happen during manual switchover from RUN to PROGRAM mode, REMOTE RUN to REMOTE PROGRAM transition and REM RUN and REMOTE TEST mode changed.
The 1785-BCM is compatible for use with a variety of PLC5 processors such as PLC-5/15 series B, -5/20, -5/25, -5/30, -5/40, and -5/60 processors. It is installed to a 1771 I/O chassis with keying locations between 8 and 10 or between 34 and 36. It requires use of a Wiring Arm with catalog number 1771-WG for fast termination of communication wires to the 1785-BCM.
