DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126 Issue 4
June 1999
Maintenance Object Repair Procedures
9-1779TONE-BD (Tone-Clock Circuit Pack)
9
will also have a Tone-Clock circuit pack in the E c arrier. This Tone-Clock circuit
pack generates c locks and provid es system tones for all carriers of the p ort
network it resides on.
High Reliability Option
Systems with the High Reliability Option (dup licated SPE, simplex PNC) have one
Tone-Clock circuit pack in each PPN control carrier, A and B. One Tone-Clock
circuit pack wil l be actively generating system clock sig nals for PPN
components, while the other will b e in standby mode, read y to take over in the
event of a Tone-Clock interchange. Similarly, one Tone-Clock circuit pack will be
actively providing system tones for the PPN, while the other will be in standb y
mode. Normally, the same Tone-Clock circuit pack will be active for both tones
and clock sig nals, but these responsib ilities may be divid ed if neither circuit p ack
is able to perform b oth functions. The status port-network PN# command will
indicate which Tone-Clock circ uit pack is actively p erforming each func tion.
For systems using the TN2182 Tone-Clock-Detector circuit pack, tone generation
and clock g eneration behaves the same as other c lock boards with one b eing
active and one being standby. But the tone detector ports (ETR-PTs) of the
TN2182 are always considered availab le and in-service regard less of the
active/standby state of the t ones or clock for a spec ific circuit p ack.
EPN Tone-Clock circuit p ack configurati on is the same as for the Standard
Reliability Option. Each EPN Tone-Clock circuit pack will be ac tive for both tones
and clock sig nals for its port network.
Critical Reliability Option
Systems with the Critical Reliability Option (SPE duplic ation and PNC duplic ation)
have two Tone-Clock circuit packs assoc iated with the PPN, as in the High
Reliability Option case, and two more Tone-Clock circuit packs for eac h EPN. For
the first EPN in a cabinet, these are in carriers A and B; for the second EPN,
where configured, they are in c arriers D and E. As in the previous case, one
Tone-Clock in each Port Network is active, supplying system clocks and tones,
and the other is in standby mode.
Tone-Clock Interchange Strategy
Tone-Clock circuit pack interchang es are controlled both by manual intervention
and by maintenance software str ategies.
The manual interchange strategy for Tone-Clock circuit packs differs slig htly
between the PPN and any EPNs on a system.