Download Series 90-70 Genius Bus Controller Manual, GFK-2017

Chapter
7
Data Monitoring, Distributed Control, and
Redundancy
This chapter describes the following types of I/O control systems:
▪
Data Monitoring: Where an additional CPU (either a PLC or a computer)
monitors inputs and diagnostics from some or all of the blocks on a bus.
▪
Distributed Control: Where two or more CPUs control different I/O blocks on the
same bus.
▪
Redundancy: The use of dual busses, dual controllers, or both.
These types of systems are possible because of the unique operation and
communications capabilities of Genius I/O devices on a bus. Each Genius I/O block
broadcasts its input messages to all other devices on the bus. Therefore, more than
one CPU can receive inputs from the same blocks.
The CPUs can communicate on the same bus, allowing formation of a common
database. In addition, any CPU can send datagram messages to any other device on
the bus.
For Additional Information, Also See:
Chapter 1, which describes non-redundant types of systems.
Chapter 4 for configuration details.
Chapter 5 for descriptions of COMMREQs that might be used in a monitoring or
redundancy system.
For information about GMR (Genius Modular Redundancy) for CPU models
IC697CPM790, CPU789, and CPU788, please see the GMR User's Manual, GFK1277, which is online at www.ge.com.
For information about Enhanced Hot Standby CPU Redundancy Series 90-70 PLC
CPU models IC697CGR772 and CGR935, please see the Series 90™-70 Enhanced
Hot Standby CPU Redundancy User's Guide, GFK-1527.
GFK-2017
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