Black Box LMC5117C-R3 End-to-End Switch Connection, AutoCross Feature for Twisted Pair Connection

Chapter 4: Install the High-Density Media Converter System II Layer 2 Modules

4.4 Auto Negotiation on High-Density Media Converter System II Layer 2 Modules

L2 modules include the feature Auto Negotiation. When Auto Negotiation is enabled, the module negotiates as a 100 Mbps full-duplex device. If the connected device can operate at 100 Mbps full-duplex, a link is established. Auto Negotiation (DIP Switch #1) is enabled by default.

If the twisted pair port on the other device does not have the ability to Auto Negotiate or if the 100 Mbps half-duplex connection is desired, then Auto Negotiation must be disabled. Half- and full-duplex settings must be set manually and match on both devices.

The following diagram shows a typical application and with three possible configurations.

End-to-End	Switch
Connection
Half-Duplex	Configure
	HDX manually
Full-Duplex	Configure
	FDX manually
Full-Duplex	Auto
	Negotiation is
	ON

TX/FX

Auto Negotiation is

OFF

Auto Negotiation is

OFF

Auto Negotiation is

ON

Configure Auto Negotiation on a L2 by adjusting the DIP Switch setting (for unmanaged modules) or via the management software. Refer to the DIP Switch table for switch location and settings.

4.5 AutoCross Feature for Twisted Pair Connection

All twisted pair ports on the L2 includes AutoCross, a feature that automatically selects between a crossover workstation and a straight-through connection depending on the connected device.

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