User guide

28
Ringing Quick References
(NTP 297-1001-131, Ringing System)
(NTP 297-1001-592, Peripheral Maintenance Guide)
Informational Notes for Ringing:
• Calls in ringing state are dropped when a warm SWACT occurs.
• Ringing is provided to all lines in the LCE frame by RG0 and RG1.
• Normally, RG0 supplies ringing to the even-numbered LCM.
• Normally, RG1 supplies ringing to the odd-numbered LCM.
• The LCM is capable of switching RGs when an RG or LD fault occurs.
• A single RG can supply ringing to all LDs in the LCE frame.
• The ANI/COIN circuit in RG0 serves unit 0 of both LCMs.
• The ANI/COIN circuit in RG1 serves unit 1 of both LCMs.
• An ANI/COIN failure in either circuit causes both LCMs to enter take-
over mode. In takeover, the remaining ANI/COIN circuit is capable of
serving both LCMs in the LCE frame.
• Reloading LCMs or performing a SWACT on the C-Side PM does not
correct problems associated with ringing.
• Troubleshooting guidelines for ringing problems can be found in Chap-
ter 31 of NTP 297-1001-592, Peripheral Maintenance Guide.
• Guidelines for changing ringing data in table LCMINV can be found in
Chapter 24 of NTP 297-1001-592, Peripheral Maintenance Guide.
• See “LM/RLM Ringing” in this QRG for a table on “Line Class Codes
by Card Type and Ring Code” and reference to table LMRNG.
RA/RB Fuse Block Reference for Ringing Check
Cross Reference of LCMs and Drawers to RA/RB Fuses
Note: See LCE Frame in this QRG for location of LSGs and drawers.
Shelf location 04 21 38 55
LCM number 0 0 1 1
LCM Unit 0101
Odd LSGs RB RA RB RA
Even LSGs RA RB RA RB
Line Drawers and Associated Fuses
BICRELAY Testing Note:
The BICRELAY Testing feature should be set up for testing only if party
lines are assigned on NT6X17 line cards, or if any NT6X19 message wait-
ing cards are used. Reference the LCMINV table and the BICTST field
where the test is set to “Y” or “N”. See the OFCENG table parameter
ALLOW_RINGING_ON_TIP_SIDE. Parameter
BICRELAY_XLCM_TEST_SCHEDULE is preset.
Side View
Front View
Alarm
Alarm
Source
Load
Source
Load
Check Source
Pin for Ringing
Check Load
Pin for foreign
voltage.
Note: Ringing is a low-frequency AC voltage that may vary during
the ringing cycle. Readings of 67 to 155 VAC may be normal.
Ringing voltages are superimposed on a DC voltage that can be
measured in the DC mode. The DC voltage may 36 to 60 volts.
Superimposed ringing may turn positive during part of the ringing
cycle.
+5V +15V -48V RA/RB
Line
Drawer
Line
Drawer
Line
Drawer
Line
Drawer
Line
Drawer