Lucent Technologies MERLIN Plus Release 2 System Manual page 305

HOW TO USE
6-14 Accessory Equipment
You can select the switch position, labeled Join, Basic, or Auto on the adapter,
required for operating the telephone or data equipment. When you have made
the appropriate selection for your needs, slide the three-position option switch to
the selected mode of operation. For the Joined Call Operation option, see the
information that comes with the GPA.
Originating a Call
Use the Basic Operation switch position if you only originate calls with your
telephone or data device. You may also answer incoming calls using your
telephone or data device. However, incoming calls ring only at your voice
terminal, not at the telephone or data device.
Using an Automatic Answering Device
Use the Automatic Operation switch position for using automatic answering
devices. Before operating these devices, program an Auto Answer-All
feature button so you can set the devices to go on automatically when you
receive ringing calls.