GE IC660BSM021 Genius Bus Switching Module

GE IC660BSM021 Genius Bus Switching Module

The Genius I/O System Bus Switch Module (BSM) is a simple, reliable device for connecting I/O devices to two serial buses simultaneously. Two versions are available: 115 VAC/125 VDC Bus Switch Module (IC660BSM120) and 24/48 VDC Bus Switch Module (IC660BSM021).

One BSM can connect up to eight discrete and analog blocks to a dual bus. Up to 30 I/O blocks can be connected to the same dual bus using additional BSMs.

This dual-bus configuration can be used to provide a backup communication path in case a bus fails.

Each bus of the dual-bus pair connects to a bus interface module (bus controller or PCIM). The system can also support CPU redundancy if each bus interface module is located in a different CPU.

The Phase B discrete block in the cluster controls the operation of the bus switching module. The first circuit on this discrete block acts as an output dedicated to the BSM. This output causes the BSM to switch buses if communication on the current bus is lost.

If an operable bus cannot be found via one of the BSM's switches, the BSM waits until communication is restored on the connected bus, or until power to the BSM controller block is cycled. This prevents the BSM from making unnecessary switches when there is no communication. After power is removed, the BSM connects the block to Bus A. The BSM is powered on only when Bus B selection is required.