Contemporary Control Systems EXP Expansion Modules User Manual - Manual (Page 24)

from the MOD HUB will extinguish the RECON indicator and
return all other port activity lights to equal brightness, thereby
isolating the defective node. For large installations, the time
saved in identifying the problem can be immense.
Line activity indicators can also point out other problems with
the network. For example, line activity indicators light up when
the MOD HUB is on and each ARCNET-compatible device that
is connected to the MOD HUB is on. If a line activity indicator
is not on for a device that is properly connected to the MOD
HUB, then disconnect the cable from the connector and
reconnect the cable to a similar vacant connector on another
module. If the indicator on the other module does not light when
the cable is connected, check the cable, the computer or the
network interface module for possible problems.
If the line activity indicator goes on when the cable is plugged
into another module, then the problem probably lies with the
original module.
If a hub port has a line activity indicator that is on but no cable
is attached to the connector, then the module is defective and
should be returned. Contact our Customer Service Department.
2.10 Supporting Extended Timeouts
Although seldom used, ARCNET networks can be configured
for extended timeouts to facilitate geographically larger
networks. In this situation, each network interface module must
be configured for the same timeout. The MOD HUB will work
with any of the four available timeout settings, but the RECON
indicator will function unreliably if the reconfiguration detection
circuitry is not configured for the same timeout as the network.
There are four jumper settings on the timing module to
accommodate extended timeouts. With the power removed from
the MOD HUB, use a small star screwdriver to remove the
timing module. Along one edge of the module is jumper setting
E1. A jumper can be found installed in the NORM position.
This is the factory setting and the default setting for standard
ARCNET networks which is the shortest setting. The next
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