The Control Network installer must ensure that the following requirements are met:
- All Cat5-Twisted Pair (TP) and fiber-optic cables should be made, installed, and tested by an experienced LAN installer.
- A DeltaV system can have a maximum of four repeater hops on the Control Network (a maximum of four hubs can be linked together in series). 10Mbit networks allow four repeater hops and 100Mbit networks allow two repeater hops.
- For Cat5 TP cables be sure
that:
- All cables are made from screened Category 5 cable with a maximum length of 100 m (328 ft) and an insulated conductor diameter of 0.89 to 0.99 mm (0.035 to 0.040 in).
- Straight-through cables are terminated with RJ45 connectors to EIA/TIA 568B pin-outs at both ends.
- Crossover cables are terminated with RJ45 connectors to 568B pinouts on one end and 568A pinouts on the opposite end.
- Cables used to cascade hubs and switches have an unshielded connector on one end and a shielded connector on the opposite end.
- Unshielded RJ45 connectors are used at all workstation connections.
- Shielded RJ45 connectors are used at all controller connections and all hub and switch connections to nodes.
- All cables are tested with the Microtest PentaScannerTM testing tool.
- Ethernet wall outlets, punchdown blocks, and patch panels are not supported.
Fiber-Optic Cables
For fiber-optic cables, use the cable and connector type specified by the equipment manufacturer for the fiber-optic ports on their equipment. The type of fiber-optic cable required could be multimode or single-mode and depends on the equipment's port specifications, the site's physical layout, and the distance between fiber-optic ports from device to device. The equipment manufacturer also specifies a fiber-optic loss budget. The acceptable loss per kilometer for the fiber-optic cable can be determined from the loss budget so that the overall cable loss does not exceed the equipment’s loss budget. The loss budget must include all fiber-optic splices and fiber-optic connector losses from end to end. The following list provides some guidelines for using fiber-optic cable:
- A multimode fiber-optic cable is generally used for 100MB/S 100BASE-FX fiber-optic communications for up to 2 Kilometers and either 50/125 micron or 62.5/125 micron multimode fiber can be used depending upon the equipment manufacturer’s specification for the fiber-optic ports. Refer to the manufacturer's specifications for cable type and loss budget.
- A single-mode fiber-optic cable is generally used for 1000MB/S 1000BASE-LX/LH (gigabit) fiber-optic communications for distances beyond 2 Kilometers and 9/125 micron single-mode fiber can be used depending upon the equipment manufacturer’s specification for the fiber-optic ports. Refer to the manufacturer's specifications for cable type and loss budget.
- A multimode fiber-optic cable is generally used for 1000MB/S 1000BASE-SX (gigabit) fiber-optic communications for distances up to approximately 500 meters and 50/125 micron or 62.5/125 micron multimode fiber can be used depending upon the equipment manufacturer’s specification for the fiber-optic ports. Refer to the manufacturer's specifications for cable type and loss budget.
- Multimode fiber-optic cable has a Modal Bandwidth specification (MHz/km) which is a distance limiting factor for gigabit communications on multimode fiber. Refer to the manufacturer's specifications for distances supported for gigabit communications over multimode fiber.
- Fiber-optic cables are terminated with ST, SC, MTRJ, or LC connectors depending upon the physical port that is used on the fiber-optic device. Refer to the manufacturer's specifications for the fiber-optic port type used on their equipment.
- All fiber-optic links should be tested for attenuation (light loss) with an optical power meter. The entire link, including all assembled cables, connectors and splices from end to end should be measured. This measurement should not exceed the equipment manufacturer's loss budget specification and at least a 3dB margin should be left.
CAUTION!Substandard cables can create serious communication problems. Make sure all cables meet the specifications listed in the "Control Network Specifications" section.