A/B Switch Achieves Reliability Via Redundancy

The Model 7283 four-channel A/B switch employs two external power supplies and internal circuitry that automatically regulates which of the two supplies will power the unit. If one of the supplies fails or is removed, the remaining supply powers the unit, a redundant scheme that ensures reliability. The switch includes a DB-25 interface with dual serial remote-control ports. Remote access is via RS-232 commands sent by way of the serial ports. Furthering reliability, all switched signals pass via copper contact relays that maintain their position and continuity even in the event of a power loss. Remote commands include changing and querying the switch position and locking and unlocking the front panel pushbutton control. ELECTRO STANDARDS LABORATORIES, Cranston, RI. (877) 943-1164.