Table 4-2. Mode Codes - AT&T MERLIN LEGEND Release 2.0 Equipment And Operations Manual

Applications
Tip/ring ports on an 012 module can be programmed either as generic VMI
ports or integrated VMI ports. The MERLIN MAIL Voice Messaging System and
AUDIX Voice Power use streams of touch-tone codes, called mode codes, to
communicate with the system's control unit. Because they use mode codes,
these applications must be connected to integrated VMI ports, MERLIN
Attendant and IVP Automated Attendant, which do not use mode codes,
connect to generic VMI ports.
Mode codes are categorized in two classes: Call Information and Other. Table
4-2 lists the types of mode codes in each class.

Table 4-2. Mode Codes

C a l l I n f o r m a t i o n
Direct inside access
Direct dial access—line/trunk
Call coverage—internal station
Call coverage—external (line/trunk)
Call coverage-other
A VMS requires touch-tone receivers (TTRs); the number required depends on
the number of VMI ports, as shown in Table 4-3. Note that these TTR
requirements are only for a VMS and do not include the TTR needs of tip/ring
sets.
TTRs are supplied by the following modules: 012, 400, and 400 GS/LS/TTR.
(The 008 OPT module also supplies TTRs, but does not support VMS
applications. )
The following symptoms indicate that the system needs more TTRs:
Single-line telephone users do not get dial tone when trying to dial out.
The voice messaging system fails to transfer calls.
Calls fail to ring or go to coverage prematurely.
4-6 Voice Messaging Systems
O t h e r
Leave word calling
Refresh message-waiting LEDs
Port taken out of service
Port restored to service
Day service
Night service