Black Box twister 7000, Installation & User Manual

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“twister” Media Converter 7000
Link Loss Carry Forward (LLCF)
The “twister” modules (with the exception of the 10Mbps BNC and TELCO
modules) have been designed with an LLCF function
for troubleshooting a
remote connection. The modules are shipped with the LLCF disabled.
When LLCF is enabled, the FX ports as well as the TX ports on the “twister”
modules, do not transmit a link signal until they receive a link signal from the
opposite port. For example, if LLCF is enabled and two “twister” modules are
connected via a fiber cable with nothing else connected to them, the Link LED
does not illuminate. When a valid link is established at the twisted-pair port, a
complete connection is accomplished.
The diagram below shows a typical network configuration using a “twister”
module for remote connectivity:
If the fiber connection breaks, or the remote device fails, the “twister”
module carries that link loss all the way to the switch/hub which generates
a trap to the management station. The administrator can then look at the
module to determine the source of the loss.
IMPOR TANT: When connecting a “twister” module with LLCF enabled to
an auto-negotiating device, force both sides of the configuration to either
10 or 100Mbps full or half duplex. This allows the interface module to
immediately see link pulses and start passing data.
Management
Station
Management
Station
Switch/Hub
w/SNMP
Switch/Hub
w/SNMP
“twister” 7000
Module
“twister” 7000
Module
Remote
up to 40km
LED lit = established link LED unlit = no link
Management
Station
Management
Station
Switch/Hub
w/SNMP
Switch/Hub
w/SNMP
“twister” 7000
Module
“twister” 7000
Module
Broken
Remote
Cable
Link Loss Carried
LED lit = established link LED unlit = no link