TRICONEX TRICON 4400 Safety Management Module (SMM)

Solid-State Relay Output
Module
Each Solid-State Relay Output Module
has three isolated sets of electronics,
called channels, which independently
accept data from the MP associated
with each channel. The channels
provide input to a voter circuit which
uses the voted value to drive the coil of
the relay. The output portion of this
module is Simplex.
The SRO Module is a non-triplicated
module for use on non-critical points
which are not compatible with highside, solid-state output switches; for
example, interfacing with annunciator
panels. The SRO Module receives
output signals from the MPs on each of
three channels. The three sets of signals
are voted and the voted data is used to
drive the 32 individual relays. Each
output has a loop-back circuit which
verifies the operation of each relay
switch independently of the presence of
a load. Ongoing diagnostics test the
operational status of the SRO Module.
SRO Modules include complete,
ongoing diagnostics for each channel.
If the diagnostics detect a failure on any
channel, the Fault indicator turns on
and activates the system alarm. The
Fault indicator identifies a channel
fault, not a complete module failure.
SRO Modules are guaranteed to operate
properly in the presence of a single fault
and may continue to operate properly
with multiple faults.
SRO Modules support a hot-spare
module. Each SRO Module is mechanically