The PLC 2000 provides for redundant
connection.
We do not recommend use of redundant processors for the following reasons:
- Only the processors are redundant.
- The processor is the most reliable component in
the system.
- Damage to the process will either arrive via the
power or the network connections. These connections are common to both
processors, thus resulting in both units being damaged. In the space shuttle
there is provided at least two systems with separate power supplies and IO
equipment. Therefore, if one goes down the user may switch to the second.
This is cost prohibitive in the detention market.
- Statistical analyses will prove the system with
the fewest components is the most reliable.
- Past performance has proven there is no need for
redundancy.
