Weed Instrument 2C32-LC-SM/SM Dual Ring Module Guide De Spécification

Weed Instrument Fiber Optics

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Continuous monitoring of the power input is crucial when redundant communications are
required. Loss of power can isolate a node and sever communication of important
applications running on your network. To help insure your network against this type of
node isolation, two power inputs are provided on each self-healing ring module. The
module alerts you if power falls outside the proper voltage range (+15 to 30VDC) on one
or both power inputs.

Relay contacts are provided for each power input and will close in the alarm condi-

tion. LEDs on each unit will also turn red which allows maintenance personnel to quickly
isolate the source of the problem. A power alarm is one of three fault conditions that
will set a Global Alarm.

Fiber is used to create a physical link between all self-healing ring modules. A fiber
ring provides a redundant path of communication in case a fiber fails or is broken. To
continue to insure this redundancy it is very important to keep this ring intact. Data on
the optical fiber lines is constantly monitored by the module. If a fiber fails to transfer
light or is broken an alarm is instantly activated.

A set of relay contacts is provided for each optical receiver and will close in the

alarm condition. Local identification of the source of the fiber failure is simple since
there is a red LED indicator for each of the optical fiber ports. A fiber alarm is one of the
three fault conditions that will set a Global Alarm.

This feature is specific to the Model 2C32. It provides an additional interface that 
creates dual redundant communications. It is an additional communication channel
between the two redundant rings and creates additional communication rings between
all adjacent self-healing ring modules. As this channel is the key to dual redundancy,
it is very important to insure communication so the module continuously monitors the
data.

A set of relay contacts is provided for the dual-ring communication channel and will

close in an alarm condition. The link alarm is also one of the three fault conditions
that will set a Global Alarm.

This feature is provided on both the 2C31 and 2C32. The global alarm is unique
because it is passed between all modules. A set of relay contacts is provided on every
module and will close in an alarm condition. As a result, only one module needs to be
connected to a remote alarm to alert when a fault has occurred. There are three fault 
conditions that set the Global Alarm:
•

Power Alarm: one or both power inputs are not between the specified input voltage
or one has failed completely. The alarm is supported by two local LEDs and two
remote screw terminal connections.

•

Fiber Alarm: no data is received at a fiber port. Both fiber ports have an 
independent remote alarm. This condition is accessed by two local LEDs and two
remote screw terminal connections.

•

Link Alarm: no data is received at the link port (Model 2C32 only). The alarm is
supported by a local LED and a remote screw terminal connector.

The 4-20mA output is a diagnostic interface that measures the light intensity at the receiver input of each of the fiber ports
and converts it into an analog output . At 4mA there is no light received indicating bad or broken fiber. As the power or light
intensity increases this measurement moves toward 20mA. These outputs are easily accessed at a terminal block connector
on the front of each module. This important feature allows for real-time analysis of fiber signal strength to identify deteriorating
fiber conditions and make replacements before a failure occurs.

The 4-20mA output is also a useful tool during installation since it can be read via a handheld meter and will provide an

indication of signal strength. This helps in finding loose or faulty connections and locating bad fiber links.