Mode Of Operation - AT&T MERLIN LEGEND Key System Planning

Control Unit

Mode of Operation

See System Reference for more
information on modes.
Your system is registered with the FCC to operate as a Key system. However,
you can program the system to operate in any of three modes:
Hybrid/PBX
Key (the factory setting)
Behind Switch
The mode of operation determines
how outside lines are provided to users
the types of operator consoles allowed
the features available and how they work.
Note: This book applies only to systems in the Key and Behind Switch modes.
To plan a system in the Hybrid/PBX mode, use PBX System P/arming.
Key Mode
In the Key mode, every line appears on a separate button on each multiline
telephone. The line buttons allow users to see activity on other telephones, join
conversations, place calls, or receive calls. Separate intercom buttons are used
to make and receive internal calls.
A Key system automatically assigns the first eight outside lines to all telephones.
You can customize this arrangement through system programming by assigning
lines or groups of lines to selected groups of telephones or to individual
telephones.
Behind Switch Mode
The Behind Switch mode is used when the system is connected to another
telephone system or Centrex. This other system (called the "host") provides the
interface to outside lines and some features.
A Behind Switch system assigns only one line (called a "prime line") to each
telephone. You must assign outside lines to telephones or groups of telephones
through programming.
In the Behind Switch mode, people can use the special features of both this
system and the host system. Compare the host systems feature list and your
system to determine which features the two systems have in common.
Once you have determined common features, decide whether you want people
to use the features following your system's instructions or following the host
system's instructions. (If you decide that the host instructions are to be used,
they must be distributed to telephone users.) In the Behind Switch mode, when
users press the Conference, Drop or Transfer buttons, a signal is sent to the
host system. Get the host system dial code for each of these buttons so that
users can take advantage of these features using the host system.
System Operating Conditions
2-9