Mission-critical systems, applications in harsh environments and facilities where even short outages, e.g. owing to cost restraints, are not tolerated are hot-standby redundancy's main fields of activity. In addition, control engineering applications with their requirement of smooth switchover, i.e. no deviation between values when switching the master CPU, are executable in this redundancy version too.
With redundancy on all system levels (i.e. hardware, system software, application programming and maintenance, monitoring interfaces) hot-standby redundancy provides maximum reliability with outstanding convenience at the same time.
The full integration of configuration, programming and monitoring in Bachmann tools shortens application creation and minimizes deviations with respect to everyday standard operating sequences. At the same time, risks in the course of maintenance operations, error corrections and application updates decrease during the process in operation.
Hot-standby redundancy combines the highest redundancy technology and the best performance possible with the customary ruggedness of every Bachmann module.
Hot-standby redundancy enhances network redundancy by the following attributes, among others:
- Fully automatic matching of process variables
- Automatic failover upon detecting internal errors
- Integrated self-tests for checking system status
- Automatic system matching (system software, configuration, applications)
- Automatic application synchronization (variance < 200 µs)
- Millisecond-precise synchronization of all stations
- Network switching time freely configurable (0 to 10 PLC cycles)
- Blumpless switchover
- Redundancy programming support in M-PLC (IEC 61131-3)
- Debugging and forcing of variables in redundant applications (M-PLC)
- Resistant to single-fault events, additionally many multi-fault scenarios are overridden on a continuous basis
Integration in SolutionCenter
- Applying, monitoring and deleting redundancy devices
- Extra support in Solution Navigator and Device Manager for configuring, monitoring and logging redundant applications
- Textual and graphical redundancy status displays
- Virtual redundancy devices with the option of applying and manipulating redundancy configurations and applications
- Redundancy master status information
- Device designation
- Current redundancy status of the entire system
- CPU information
- System software information
- Network information
- Redundancy application status information
- Current redundancy status (REDUNDANT/SINGLE/ ERROR)
- Runtime state (RUN/STOP/ERROR)
- Error status codes
- Synchronization status
- Cycle time
- Maintenance interface for redundancy systems integrated (execution of commands on both master CPUs at the same time)
- All commands and monitoring mechanisms are available to the operator as open user interfaces and/or as system variables.