FCM2F10  FoxboroT DCS现场总线模块(fbm)

FCM2F2

Plant installation costs can be significantly reduced by placing the rugged standard200 Series FoxboroT DCS Fieldbus Modules (FBMs) much closer to theircorresponding field devices. Long runs of signal cables can then be replaced by oneor two fiber optic pairs carying multiplexed l/O signals. The 200 Seres FieldbusCommunications Modules (FCMs) support this capability over nominal distances of 2,4, or 10 kilometers.
FCMs are fiber optic communications extenders that permit 200 Series FBMs to beinstalled remotely and closely to the plant processes.
The three versions, FCM2F2 (RH914YZ),FCM2F4 (RH917JA), and FCM2F10(RH916TQ), offer nominally maximum baseplate-to-baseplate fiber optic cablingdistances: up to 2 km (1.24 mi), up to 4 km (2.48 mi), and up to 10 km (6.21 mi),respectively.
The FCMs are mounted on standard baseplates in pairs for redundancy. Non-redundant configurations require only a single FC.
Unaffected by electrical noise (EMl, RFl, and lightning), fiber optic cabling provides aversatile means of extending signal communications. lt can be used in areascontaining rotating machinery, arc welders, and so forth, and can be installed in cabletrays containing high voltage power lines, or in outdoor areas exposed to lightninghazards.lts electrical isolation characteristics provide protection from voltagedifferentials and ground loops.
Figure 1 shows an example of redundant configuration with baseplates (containingFCMs) linked point-to-point with fiber optic cabling. This cabling configuration shows asingle fiber optic segment, interconnecting two baseplates. However, up to three fiberoptic segments can be used to interconnect the (maximum) four baseplates.
Maximum fiber optic cabling distance between any two baseplates is 10 km (usingFCM2F10s (RH916TQ)), with the total fiber optic cabling distance between thebaseplates (all cable segments) not to exceed 20 km (10.42 mi).

FCMs have a rugged extruded aluminum exterior for physical protection of the circuits. Enclosures specially designed for mounting of the FBMs and FCMs can provide various levels of environmental protection for the FCMs, up to harsh environments (Class G), per ISA Standard S71.04.
The FCM can be removed/replaced from the baseplate without removing power. Six light-emitting diodes (LEDs) incorporated into the front of the FCMs indicate the status of network activity to/from the module Fieldbus and fiber link, and the FCMs operational status.

FCMs mount on a standard baseplate. The baseplate includes signal connectors for Fieldbus, power, and I/O cable connections. A baseplate can support up to eight
FBMs, or a combination of FBMs and FCMs.
When connecting two baseplates (with redundancy) with fiber optic cable, a pair of FCMs is required for each baseplate (for a total of four FCMs).
For non-redundant configurations, each baseplate requires only a single FCM. Multiple baseplates in the same enclosure do not necessarily require FCMs and fiber optic cabling. Any baseplates within 60 m (196.85 ft) can link together with the  standard, twinax-pair cable.