GE 90-70 manual Single Bus Genius Networks, Dual Bus Genius Networks

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Single Bus Genius Networks

When using single-bus Genius networks in a Hot Standby CPU Redundancy system, one Genius Bus Controller for the bus must be located in the Primary PLC and one in the Secondary PLC. There can be multiple Genius busses in the system.

The bus controllers in the Primary PLC are assigned Serial Bus Address 31. The bus controllers in the Secondary PLC are assigned Serial Bus Address 30. Data from Serial Bus Address 31 in the Primary PLC is the "preferred" data. If the GHS Control Strategy is used, the Primary PLC is normally the active unit in the redundancy system.

Each bus can have up to 30 Genius devices connected to it. One Serial Bus Address must be reserved for a Hand-held Monitor. Any type of Genius device can be connected to the bus. A Genius I/O device will use outputs from Serial Bus Address 31 in preference to data from Serial Bus Address 30.

When using the GHS Control Strategy, the blocks receive outputs from the bus controllers in the active unit. With the GHS Control Strategy, it is not necessary to transfer outputs from the active unit to the backup unit.

Secondary Unit

P C B R G G G S P T C B B B

UM M C C C

30 3030

Primary Unit

PC B R G G G SP T C B B B

UM M C C C

31 31 31

		Genius Bus
		Genius Bus
		Genius Bus
PS	Power Supply
CPU	Central Processor Unit.
RCM	Redundancy Communications Module
BTM	Bus Transmitter Module
GBC	Genius Bus Controller

BLOCK.. Genius I/O Block (or Field Control)

Genius Devices

Genius Devices

Genius Devices

When using the GDB control strategy, all redundant Genius outputs must be transferred from the active to the backup unit. Therefore, outputs are determined by the active unit regardless of which bus controller provides the outputs to the blocks.

As a safety feature, a watchdog timer protects each Genius I/O link. The Genius Bus Controller periodically resets this timer. If this timer expires, the bus controller stops functioning and the Channel OK LED turns off. If this happens in a CPU Redundancy system, the other bus controller provides data to the Genius I/O blocks. The cause of the failure must be fixed to re-establish communications.

Dual Bus Genius Networks

When using dual bus Genius networks in a Hot Standby CPU Redundancy system, two Bus Controllers for the bus pair must be located in the Primary PLC and two more in the Secondary PLC. There can be multiple dual bus pairs. The bus controllers in the Primary PLC are assigned Serial Bus Address 31. The bus controllers in the Secondary PLC are assigned Serial Bus Address

GFK-1527A Chapter 2 System Components 2-11