Black Box LB1351A manual General Description, Far End Fault Signaling FEF feature, Preferred Port

Black Box®LB1350A/LB1351A

General Description

The Black Box®LB1350A/LB1351A is a shared and buffered media converter. It converts 100Base-FX signals received on its F/O interface in 10/100Base-TX signals and distributes them to 4(3) copper (shielded RJ-45) ports. Each of these ports is buffered; furthermore, factory set VLAN forms groups each including one copper port and the common F/O port, providing the users with basic security (no connection between the users). This architecture allows 4(3) users to share one F/O link with dramatic (up to 75%) savings.

The copper ports are auto-negotiating and will automatically adapt themselves to the capacity of the users for highest performance (will negotiate 10/100 and FDX/HDX). Nevertheless, in some cases it may be necessary to force certain operating modes.

For this purpose, all copper ports may be (individually) forced to 10Mbps/FDX operation and port #4(3) (the preferred port) may be forced to any desired combination (altogether 4 combinations) of HDX/FDX and 10/100.

Full front panel diagnostics provide information on the operation mode of every port. The F/O port is configured by default to FDX but if desired may be set to HDX as well. However it is essential to remember that when in HDX, the F/O link maximal distance drops to 412m or less.

The Black Box®LB1350A/LB1351A is available with a variety of multi-mode and single- mode interfaces with distance ranging from 2km to 40km.

The Black Box®LB1350A/LB1351A is packaged in a rugged “half rack” enclosure allowing elegant and safe deployment in a variety of environments: desktop, 2 units on a 19” rack-shelf or within a standard “half 19” rack (optional brackets required).

Its internal, high-power auto- range switching power supply ensures easy, safe and error-free deployment and enhanced MTBF.

The managed version – Black Box® LB1351A – provides full in-band SNMP manageability (both monitoring and control) - see Appendix A ( pages 19-37 ) Port priority schemes are also a part of the management.

5. PREFERRED PORT

TP port #4 of the Black Box®LB1350A (or #3 of the Black Box® LB1351A) provides additional functionalities comparing to the other copper ports.

Full operation mode selection

While all the TP ports provide auto-negotiation and forced 10Mbps/FDX operation, this preferred port may be set via the front panel DIP switches to force all possible operation mode options: 10/HDX, 10/FDX, 100HDX and 100FDX. See section 12 for detailed Dip switches setting ( page 14 ).

Recommendation: use the preferred port for connection of the most critical or heavy traffic user of the four, even if you do not implement the special features described above

6. Far End Fault Signaling ( FEF ) feature

When the device detects F/O Link Loss (receive side) it automatically sends a Far End Fault signal to the remote device. If such device is another Black Box®LB1350A/LB1351A or any device which supports such feature – then it will indicate F/O Link Loss as well. By activating TEST mode (by TEST switch - #8 MODE SETUP Dip switches on the front panel ) this function may be disabled .The picture below depicts this functionality.

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