Schneider Electric 840 USE 106 0 manual Enable Keyswitch Override, Software, Control Example

Using a Quantum IEC Hot Standby System

Enable Keyswitch Override

Keyswitch

Override

CAUTION

Animation Mode or Reference Data Editor Hazard

If you use the animation mode or reference data editor (RDE) of Concept to enable the keyswitch override while the Hot Standby system is running, the Primary controller immediately reads bits 14 and 15 to determine its own state and the state of the Standby.

Failure to follow this precaution can result in injury or equipment damage.

If both bits are set to 0, a switchover occurs and the former Primary backplane goes offline. The new Primary backplane continues to operate.

A Software	For example:
Control Example
	You have enabled the keyswitch override and set the operating mode of controller
	B to Offline. Now the system is powered up and you want to put controller B in RUN
	mode.
	The keyswitch does not work, so you must rely on user logic. There are two ways
	you can proceed.

120 840 USE 106 00 January 2003