Schneider Electric 840 USE 106 0 manual Hot Standby Status Register, Bits in the Hot

Using a Quantum 984 HSBY System

The Hot Standby Status Register

Hot Standby	The status register is register 40012, the third register in the nontransfer area. The
Status Register	command register, which is defined in the top node, has been placed outside the
	nontransfer area, as required.
	The third register in the nontransfer area is the status register. Use this register to
	monitor the current machine status of the Primary and Standby controllers.
Bits in the Hot
	In the example, the status register is 40012.

Standby Status

Register	This PLC in OFFLINE mode = 0 1
	This PLC running in primary mode =1 0
	This PLC running in standby mode = 1 1

The other PLC in OFFLINE mode = 0 1

The other PLC running in primary mode =1 0

The other PLC running in standby mode = 1 1

PLCs have matching logic = 0

PLCs do not have have matching logic = 1

This PLC’s switch set to A = 0

This PLC’s switch set to B = 1

1

2

3 4

5 6

7 8 9 10 11

12

13

14

15

16

840 USE 106 00 January 2003 81