Self-monitoring is an inherent advantage of
microprocessor-based relays. By nature and by design, digital
relay components fail more securely compared with analog
components. Data and code integrity checks, watchdogs, and
other standard and optimized integrity functions ensure failsafe
operation of the digital subsystems of a microprocessorbased
relay. Internal data buses are protected with strong data
integrity (redundancy) codes. Power supply rails are
continually monitored to ensure digital relay subsystems are
supplied with proper voltages to ensure the relay fails safely
before any components start operating in a nondeterministic
state where the built-in safety mechanisms could be defeated.
Tripping and control outputs are actuated using digital
techniques, ensuring fail-safe behavior even if the driving
subsystem misbehaves. Communications ports are protected
with data integrity checks.
for best-in-class relays.