Xerox FaxCentre F110, Service Manual

Page: 163 / 204

General Procedures / Information
FaxCentre F110 12/04 6-77
Incoming Ring (On-Hook)
To signal the Terminal Equipment, whether an incoming call is pending, a ring signal is generated
at the line by the network.
Figure 10
The ring signal is specified by its amplitude, its frequency and the cadence (On- and Off-time re-
lationship). The ring signal transmission is terminated when a valid loop current is detected by the
network. The ring amplitude is added to the line On-Hook voltage.
CLI Polarity Reversal (On-Hook)
The signalling of some network services (e.g. CLI) is indicated by a reversal of the line voltage,
which means the polarity of the voltage between the line connection LA, LB changes.
Figure 11
LA, LB
Ring On-time
[V]
max. On-Hook
min. Off-Hook
Ring Off-time
Ring Phase
LA, LB
On -> Off-Hook transition time
Polarity Reversal
[+V]
On-Hook On-Hook
+ max. On-Hook
+ min. Off-Hook
[-V]
- min. Off-Hook
On-Hook Signalling