Schneider Electric 840 USE 106 0 manual Hot Standby Command Register, Range, Register. However

Using a Quantum IEC Hot Standby System

Hot Standby Command Register

Range	You may enter any number in the range 1 ... n, where n is the last configured 4x
	register. However:

the command register must be part of the area of state RAM that gets transferred

lfrom the Primary to the Standby controller on every scan.

therefore the command register must not be within the range of the nontransfer area, which you specify in the nontransfer area of the Hot Standby dialog.

		CAUTION
		Hot Standby Command Register Hazard
		Be sure the register you select as the Hot Standby command register is
		reserved for this purpose and not used for other purposes elsewhere in
		user logic
		Failure to follow this precaution can result in injury or equipment
		damage.
Keyswitch
	You may choose to override the keyswitch on the front panel of the CHS 110
Override and	modules for security or convenience. If you override the keyswitch, the command
Run Mode	register becomes the means for taking the CHS 110 modules on or offline.
	By default, the keyswitch override is disabled. The Hot Standby dialog allows you to
	enable it.

If you enable the keyswitch override, the Offline/Running operating mode of the controllers at startup are determined by the values you set to bits 14 and 15 of the command register. These bits are represented as the Run Mode for controller A and B (depending on the designation slideswitch). Remember, that when the keyswitch override is enabled you cannot initiate a program update (program xfer) at the CHS 110 module in the Standby rack.

As long as the keyswitch override is disabled the settings for the Run Mode may be ignored.

840 USE 106 00 January 2003 119