GE Fanuc IC660BSM021

Part Number: IC660BSM021

The IC660BSM021 is a Genius I/O Bus Switching Module (BSM) designed for simultaneous connection of input and output devices to two serial buses. As a variant of the BSM series, the IC660BSM021 operates specifically on 24/48 VDC, while its counterpart, the IC660BSM120, is powered by 115 VAC/125 VDC. This module supports a maximum of eight discrete and analog blocks connected to a dual bus, with the capability to integrate up to 30 I/O blocks through additional BSMs. This configuration enhances system reliability by providing a backup communication pathway in the event of bus failure. Each bus in this dual bus architecture utilizes a bus controller or PCIM, and system redundancy is supported if the bus interface modules are managed by different CPUs. The operational control of the IC660BSM021 is managed by the phase B discrete block of the cluster, which governs the switching mechanism. An output circuit dedicated to the BSM allows for bus switching whenever a communication loss occurs. Should an operational bus be unavailable after a switch, the module will wait for communication restoration or a power cycle before attempting to switch again, thereby preventing unnecessary operations. When de-energized, the IC660BSM021 defaults to connecting blocks to bus A and only activates for bus B when required; an LED indicator confirms the status of bus B. Additionally, bus switching can be executed via the CPU or a handheld monitor. Note that the IC660BSM021 and IC660BSM120 are functionally identical, differing solely in their power supply specifications.