Fibre Interface Non Addressable

Description

These units interface glass fiber optical cable with plastic fiber optical cable and support redundant wiring topology. In many applications this is necessary because glass fiber can bridge much longer distances than plastic fiber. Any conversion to glass fiber must be converted back to plastic fiber before other Praesideo units can be attached since they all have plastic fiber interfaces. This means that these units are always used in pairs.

Each interface can use an external 48 VDC power supply to provide power for itself as well as for remote parts of the network. If there is no external power source the interface uses power from the network controller. The PRS FIN and PRS FINS have two control inputs. These can be used to accept e.g. the fault output of the external power supply (UPS) allowing the units to monitor the power supply and report faults to the network controller. The fiber interfaces have two LEDs for diagnostic purposes.

The PRS FINNA is the same as the PRS FIN except that it has no network node address. This has the advantage that the unit does not occupy one of the 60 possible addresses in the network. It also has the disadvantage that without an address it is not possible to access the status of the two control inputs as it is with the PRS FIN. The PRS FINS is the same as the PRS FIN except that it accepts single mode glass optical fiber instead of multi mode glass optical fiber. However this does not increase the maximum permitted cable length of a Praesideo network.