Module Connections

Using Fiber Optics in a RIO System

The following represent four typical configurations that show the wide range of the network architecture:

Point-to-Point topology
Bus topology
Tree topology
Self Healing Ring topology

Point-to-Point Topology with Fiber Optic Repeater

Point-to-point configuration (see the following figure) allows communication over the distance of up to 16 km through harsh industrial environments. The following figure shows the point-to-point configuration.

NOTE:

Using 2 optical fiber pairs provides a better service and diagnostics.
Using only one fiber pair, looping back the unused optical ports with a short fiber helps using the diagnostics.

For more details on the diagnostics, refer to the Modicon 140 NRP 954 00 and 140 NRP 954 01C Fiber Optic Repeater Modules User Guide.

Bus Topology with Fiber Optic Repeater

This type of configuration is used when it is required to increase the length of the fiber link and increase the distance between drops on the RIO network.

CAUTION

EQUIPMENT FAILURE

The loss of a single fiber optic repeater in this configuration disables the rest of the network. It is suggested that the Self Healing Ring configuration be used to avoid this problem.

Failure to follow these instructions can result in injury or equipment damage.

The following figure shows the bus topology:

NOTE: The total distance between the first and the last fiber optic repeater is limited by the maximum allowable power loss from end-to-end (16 km over 9/125 µm fiber). Power loss includes the fiber optic cable attenuation, connector losses at the fiber optic receiver and transmitter ports, and the system margin of 3 dB.

NOTE: At each end of the bus, looping back the unused optical ports with a short fiber helps using the diagnostics. For more details on the diagnostics, refer to the Modicon 140 NRP 954 00 and 140 NRP 954 01C Fiber Optic Repeater Modules User Guide.

Tree Topology with Fiber Optic Repeater

Tree topologies, which cannot be established with coaxial cable alone can be built legally using fiber optic repeaters.

NOTE: The limitations in bus and self-healing configurations are applicable for each drop in tree topology.

The following illustration shows an example of a tree topology:

NOTE:

Using 2 optical fiber pairs provides a better service and diagnostics.
Using only one fiber pair, looping back the unused optical ports with a short fiber helps using the diagnostics.

For more details on the diagnostics, refer to the Modicon 140 NRP 954 00 and 140 NRP 954 01C Fiber Optic Repeater Modules User Guide.

Self-Healing Ring Topology with Fiber Optic Repeater

This configuration can be achieved by connecting the unused fiber optic ports of the first and last 140 NRP 954 01C directly or through the fiber optic repeater. This type of connection has all the advantages of the previously described configurations, along with built-in redundancy. A broken connection between any two Quantum NRP modules in the ring will automatically reconfigure the RIO network and continue the communication.

NOTE: The maximum length of the fiber cable in a ring configuration, 16 km, is calculated in the the case of a break that occurs anywhere (back-loop included).

Hot Standby Systems with Fiber Optic Repeater

The following figure shows an example of hot standby systems using fiber optic repeaters:

NOTE:

Using 2 optical fiber pairs provides a better service and diagnostics.
Using only one fiber pair, looping back the unused optical ports with a short fiber helps using the diagnostics.

For more details on the diagnostics, refer to the Modicon 140 NRP 954 00 and 140 NRP 954 01C Fiber Optic Repeater Modules User Guide.

Backplane Integration

Instead of placing each fiber optic repeater modules with its own power supply module(s) in a standalone backplane, you can take the advantage of the quantum form factor.

The following figure shows two segments of RIO coaxial cable connected point-to-point by two 140 NRP 954 01C fiber optic repeaters placed on the Quantum racks where the RIO head and RIO drop modules are located:

NOTE:

Using 2 optical fiber pairs provides a better service and diagnostics.
Using only one fiber pair, looping back the unused optical ports with a short fiber helps using the diagnostics.

For more details on the diagnostics, refer to the Modicon 140 NRP 954 00 and 140 NRP 954 01C Fiber Optic Repeater Modules User Guide.

Recommended Materials for Fiber Optic Links

Modicon does not manufacture fiber optic products such as cables, connectors, or special tools. However, we have experience with third party suppliers of materials and can give some guidelines on what will work with our products.

Observing Safety Precautions

Before installing the 140 NRP 954 01C fiber optic repeater module, read the warning messages below. Follow them at all times during the installation of the fiber optic repeater.

DANGER

SEVERE EYE DAMAGE

Do not view the ends of fiber optic cable under magnification while a transmit signal is present on the cable.

Failure to follow these instructions will result in death or serious injury.

NOTICE

INOPERABLE EQUIPMENT

Do not remove the protective coverings from the optical cable port and optical cable tips until immediately fiber cable connection to the cable port.

After removing the protective coverings, never touch exposed parts such as the ferrule.

After connecting the fiber cable, retain the protective coverings for future use.

Do not remove the protective covering from the unused connector.

Failure to follow these instructions can result in equipment damage.

Before Starting

Prior to installing 140 NRP 954 01C fiber optic repeater, network cables must be prepared and installed to the repeater’s site with their connectors.

To prepare optic cables:

Follow the cable manufacturer’s recommendations for routing, installing, and testing the cable. Take care when terminating the ends of each fiber optic cable in order to minimize loss of optical signal. Follow the manufacturer’s guidelines for installing optical connectors.
Test the cable for proper attenuation prior to the connection of the fiber optic repeaters. The cable ends should be accessible at each fiber optic installation site. Allow sufficient cable length for a service loop and strain reliefs.
Label each cable end to facilitate future maintenance.

To prepare and install coaxial cables, refer to Remote I/O Cable System Planning and Installation Guide.

Connecting the Fiber Optic Cable

Install the fiber optic cable to the 140 NRP 954 01C module’s LC duplex connectors as described in the following table:

Step	Action
1	Remove the dust plugs from the LC connectors of the fiber optic cable as shown in the following figure. Save the dust plugs for future use.
2	Inspect and clean the fiber optic end faces of the LC connectors.
3	Remove the dust plugs from the LC duplex connector as shown in the following figure:
4	Immediately attach the fiber optic cable to the LC duplex connector of the module as shown in the following figure:

Compatibility Rules

Depending on the PV (Product Version) and SV (Software Version) of the CRA modules, the 140 NRP 954 01C may be incompatible.

The following table gives the compatibility rules between the 140 NRP 954 01C and CRA modules:

CRA Module Reference	PV	SV	Compatibility
CRA Module Reference	PV	SV	Communication	Remote OS Update via S908 Bus
140 CRA 93• 00	≤ 08	2.0	Yes	Yes
	09	2.0	No(1)	No(2)
	≥ 10	2.01	Yes	No(2)
PV Product version SV Software version (1) An upgrade of the SV to 2.01 makes the module communication compatible. NOTE: Upgrading the software version of the CRA module from 2.0 to 2.01 for CRA modules PV 09 is mandatory before using 140 NRP 954 01C in the RIO network. (2) For CRA module with SV ≥2.0, OS update is only possible out of the RIO network.

The 140 CRA 93• 00 firmware upgrade is done through Modbus or Modbus Plus using the Control Expert OS loader tool. The procedure to follow is described in the Quantum Operating System Upgrade and Update Procedure.