Features

• Automatically transfers control to standby PLC upon loss of I/O scan

or “heartbeat” pulse from the active PLC

• Switches both remote I/O and serially attached operator interface devices

• Enables PLC logic to monitor status and control switchover, if desired.

• Allows optional manual switchover capability

• Uses high-reliability relays to directly connect the active PLC and remote

I/O without intervening

electronics.

• Defaults to a user-defined switched position on power loss or hardware

failure

• Provides LEDs to visually indicate status of control

• Transfers up to 4096 words of critical data between active and standby

PLCs every scan