Specifications

5-2 Ringing system maintenance
297-1001-131 Standard 06.01 October 2000
RG overload control - Series II peripherals
Series II peripherals are all of the LCM-based peripherals. As with the Series
I peripherals, the ringing bus on the Series II peripherals is monitored by
current and voltage monitors, which react when current and voltage thresholds
on the ringing bus are exceeded.
The current monitor detects current through the ringing bus. When the current
threshold is exceeded, the current monitor notifies the PM software, which
stops processing any additional ringing requests until the current level drops
below the threshold or ringing on one or more lines is canceled.
The voltage monitor detects the voltage on the ringing bus and reacts when the
bus voltage exceeds an upper limit or falls below a lower limit.
Troubleshooting
This section provides troubleshooting information for the DMS-100 ringing
system. Specifically, the section describes logs and alarms associated with the
ringing system and provides guidelines for clearing some of the most common
customer complaints regarding ringing.
Log reports associated with ringing
The following classes of logs are associated with ringing:
• pre-trip
• no ring current
• drawer slot occupied
• ring slot occupied
• subcycle order failure
• ringing time-out
• bad CP IO msg
• ringing trouble
Following is a description of these classes of logs.
Pre-trip
Pre-trips can be caused by spurious off-hook signals on the terminating line.
These signals appear as instantaneous shunts from tip to ring and are usually
experienced on lines having high capacitance and low resistance (no lower
than 1900 Ohms).
Ringing pre-trip occurs when the DMS-100 switch detects on-hook within a
predetermined interval of time after detecting an off-hook. After the DMS-100
switch detects an off-hook on a line, it resupervises the line for off-hook to