The RelComm Automatic Backup Switch ABS is three switches in one package. a modem A-B switch, an automatic A-B fallback switch, and a failover switch.
A dedicated line and modem (primary) can share a computer’s communication port with a dial-up modem (alternate) in these three selectable ways:
1.The ABS can be operated as a manual A-B switch.
2. In its automatic mode, communication with the primary or alternate modems cannot be interrupted, and access cannot be granted to the other until communications have been completed.
3.The ABS can be short jumpered to allow for BREAK in PRIORITY by the alternate modem thereby providing the security of a backup communications channel in the event of a dedicated line failure. In this instance,when the alternate raises CTS,DSR or DCD (Pin 5, 6 or 8) the ABS automatically makes the connection to the alternate modem.When CTS,DSR or DCD is lowered,the ABS releases the connection to return to the primary modem connection. All required leads of the RS-232 interface for asynchronous or synchronous operations are switched (12 leads total).
Power: 115/220 VAC, 50 – 60 Hz Internal
Weight: 2.7 lb. (1.2 kg)
Size: 2.2″H x 8″W x 11.3″D (5.6 x 20.3 x 28.7 cm)
Enclosure: High-impact ABS plastic
Connectors: (3) Rear-mounted DB25F
Indicators: (2) Front panel LEDs
Switch: (1) 3-position Mode Select switch