Along with the rapid development of computer
technology and the decrease of its cost, as well as with improvement of
its reliability, a great part of process control has become dependent on
computer.
However, a computer cut-down by possible system failure may cause serious
problems, and it is common to introduce certain backup system. One of the
ways is to double-equip the system including CPU, yet an increased cost
is not avoidable. For constructing a backup system at a lower cost, an application
of Analog Backup Station model ABF is recommended. The Figure 1 shows the
system configuration.
When the computer falls down, maintaining the latest operation outputs can
prevent a sudden change of the valve travel. |
