A/B Automatic Switch

Versatile functionality and unmatched reliability in an affordable, stand-alone package.

The only three-mode A/B automatic switch to ensure high availability and protect against unintended switching.

Automatically switches between two lines
The Omicron A/B Automatic Switch protects data communications from line or modem failure by automatically switching between a primary and a secondary DCE. It is ideal for manned or unmanned sites and provides cost-effective security for leased line backup or equipment redundancy. The A/B Switch is available with either RS-232D or V.35 interfaces.

Three switching modes
The A/B switch is triggered by a user-defined change or combination of changes in the signal state of either circuit and has three switching modes:

Fallback mode is used when the secondary line is reserved for backup. If the primary line fails, the common channel is switched to the secondary line. As soon as the primary line is restored, the switch falls back to its original position.

Line contention
Line contention mode is used when both primary and secondary lines require access to the common channel. The lines contend for the common channnel by generating their user-defined triggers. The first line to claim the common channel occupies it until transmission is complete. While the common channel is occupied, the idle line may signal the A/B Switch but must wait for the occupying line to complete transmission before being connected.

Priority mode, like line contention mode, is used when both primary and secondary lines contend for a common channel. However, the primary line has priority, and may take over the common channel from the secondary line at any time.

Security features & manual override
Security against accidental switching is provided by two features. The anti-glitch control filters out electrical line noise which might otherwise trigger an inadvertent switchover.The delay feature prevents switchover due to transient changes; switchover is delayed until the new signal state has been stable for a strap-selectable period of 1 to 64 seconds.
Power outages cannot break the circuit established by the A/B Switch. Latching relays maintain the current switch position during the outage and the subsequent power-up.
Automatic switching may be overridden manually from the front panel by dedicating the DTE to either the primary or secondary line.

Front panel LEDS indicate status and signal states
The Omicron A/B Switch provides front-panel LEDS indicating the current signal status and switch position.

The only three-mode A/B automatic switch to ensure high availability and protect against unintended switching


Send e-mail to: info@omicron.ca