Nortel DMS-100 Series Maintenance Manual page 125

The following signals are transmitted from the SMS to the RCS:
negative loop mode
channel test
positive loop mode
ground start
–R ringing
positive coin check
positive coin control
negative coin control
negative coin check
The following signals are transmitted from the RCS to the SMS in response
to SMS signals:
on-hook
off-hook
coin ground
unequipped
These signaling states associate with specific A- and B-bit patterns. The
Bellcore document Digital Interface Between the SLC96 Digital Loop
Carrier System and a Local Digital Switch (TR-TSY-000008) describes
these bit patterns.
PBX line The private branch exchange line provides capabilities for a loop
start and a ground start.
Custom calling services The following custom calling services are
provided:
speed calling
call waiting
three-way calling
call forwarding
DMS-100 Family SMS Maintenance Manual XPM10 and up
SMS signaling 3-9