Allen-Bradley ControlNet PLC-5 User Manual page 6

ii
Appendix B
Appendix C
Appendix D
Appendix E
Appendix F
1785-6.5.24 February 1999
Backup States
Chapter Objectives ............................................................... B-1
Invalid Backup State ...................................................... B-2
No Control Backup State ............................................... B-3
Primary Backup State ..................................................... B-4
Lonely Primary Backup State ........................................ B-4
Secondary Backup State ................................................. B-5
Backup State Transitions ..................................................... B-5
Qualification ................................................................... B-5
Data Table Crossloading
Chapter Objectives ............................................................... C-1
Data Table Crossloading ...................................................... C-1
On-Demand Data Table Crossloads ............................... C-2
Data Table Crossload Time ............................................ C-7
Data Table Crossload Data Latency ............................... C-7
Effect of Data Table Crossloading on the ControlNet Channel
......................................................................................... C-7
Inhibiting Data Table Crossloads ................................... C-7
Data Table Crossload Diagnostics ................................. C-8
Performing Data Table Crossloads Via Your Applications
......................................................................................... C-8
Program Synchronization
Chapter Objectives ............................................................... D-1
Program Synchronization ..................................................... D-1
Determining Which Mode to Use .................................. D-2
Using Synchronous Mode .............................................. D-2
Application Guidelines
Chapter Objectives ................................................................E-1
Redundancy Considerations ..................................................E-1
Switchover Considerations ...................................................E-1
Why Transfer Information? ............................................E-1
What Information Should Be Transferred? .....................E-2
When Should the Information Be Transferred? ..............E-3
How Often Should the Information Be Transferred? ......E-3
Performance Considerations ...........................................E-4
Comparison to the 1785-BCM System
Chapter Objectives ................................................................F-1
Comparison to the BCM System ..........................................F-1