The Global User Station (GUS) requires a LCN Media Adapter Unit (MAU) Honeywell part number 51305348-100 . LCN 'A' and 'B' are connected and provide LCN access to a GUS station.

The MAU part number 51305348-100 needs to be aluminum and not a steel casing. Newer ones are MAU REV F with PWA/board version D (and later).

MAU and MAU cable sold separately:
MAU - 51305348-100
MAU Cable - 51305380-100

Quick rules for MAUs:

1. Should have aluminum casing, magnet should not stick to it, original MAUs were heavier metal types that created zinc whiskers from the casing to the internal board, causing cable noise.
2. Should not be too hot to the touch (above 122 deg. F, assuming ambient of 75 deg. F), compare to other MAUs, if one seems much hotter than the others, replace it.