Industrial design


  • Class I, Division 2 hazardous locations certified
  • CE approved

Single and Dual Channel Self Healing

  • Rings for high reliability
  • Highest number of nodes supported
  • Fully compliant with the ControlNet specification
  • Robust Multi-Break Management algorithm

Many industrial processes require very precise control. Failure of communications between the various elements of a control system may cause serious problems. Therefore, the communication systems employed have to be robust. NSPI’s 2C31 and 2C32 Self-Healing Ring Modules address this need by providing multiple communication paths between the various elements of the system, and utilize advanced Downstream Multicasting technology. In the event of a failure on one communication path, communications are still maintained along a secondary path or, in the case of a dual ring, tertiary paths.

Downstream Multicasting transmits an incoming message in multiple directions and insures that while directing the message toward all nodes in the ring it is never retransmitted back to the point of origin. This communication method employs a “Master” or ring control module which will direct traffic and guard against duplicate message delivery. Each fiber ring must include one master module to insure proper communication between all nodes in the ring.

Primary data is defined as the data that arrives at the module first. When a data packet flows around the ring, the primary data is delivered to other ControlNetâ„¢ segments. Secondary data will only be used in the case of fiber break. For critical applications the Model 2C32 provides a highly robust, dual-channel ControlNetâ„¢ solution. As with the single ring, Downstream Multicasting insures that data is delivered to all consumers within the appropriate network update time. In this configuration, not only is a second ring provided to support both Channel A and B ControlNet data packets, a third or tertiary communication path is also available. Because there is an additional path, more fiber breaks are supported without any loss in either communication channel.

Because redundant systems are typically used in operations that can’t afford a loss in data or any downtime, the 2C31 and 2C32 are supplied as standard with an extensive set of powerful diagnostic tools to warn against any faults or impending system failures.


Dual-Ring link

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.

Small form factor, high performance laser optics

  • 1310nm lever-latch SFP laser transceiver
  • Real-time indication of fiber optic health
  • Single/Multi-mode conversion available

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.


Global ring failure alarm with comprehensive diagnostics

  • Indicator and relay monitor
  • Four additional alarm relay outputs
  • Minimizes downtime

Compact enclosure

  • Reduced installation space required
  • Stand alone 35 mm DIN-rail mounting

Power input quality

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 condition. 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.

Optical fiber fault

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.

4-20mA output

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.