T-Lbcn; T-Psc - Fujitsu FLM 150 ADM Maintenance And Trouble Clearing

Maintenance and Trouble Clearing
FJTU-320-515-480
3.66

T-LBCN

T-LBCN is reported when transmitter laser bias current exceeds the threshold
level.
Table 3-64: T-LBCN (Threshold Violation for Normalized Laser Bias Current)—Transient Condition
AID
Direction
Type
EQPT RCV
3.67

T-PSC

PSC is the count of the number of protection switches for each OC-3 line.
Table 3-65: T-PSC (Threshold Violation for Protection Switch Count)—Transient Condition
AID
Direction
Type
OC3 NA
OVTG
Issue 9, May 1999
Probable Cause
• Laser approaching
end of useful life
• Faulty optical
transmitter unit
• Improperly set
threshold
Probable Cause
• Intermittent • The FLM 150 ADM provides a lockin function to prevent
digital errors
• Loss of DS3,
EC-1, or optical
signal
• Faulty MC1A
plug-in unit
• Faulty optical
transmitter unit,
or optical
• See LOS.
receiver unit
• Replace the faulty MC1A or optical unit as required.
• Improperly set
• See also APSB.
threshold
• Refer to TL1 Commands practice FJTU-320-515-274,
FNC and FNC Customer Use Only
Suggested Corrective Action
• Replace the optical transmitter unit.
• Verify the proper threshold levels with local standards.
The allowable threshold values are 0.5 to 2.0. Factory
default = 1.5.
• A threshold set too low causes a premature indication
that a laser is nearing the end of its useful life.
Suggested Corrective Action
successive switching of the unit and line caused by
intermittent digital errors. Lockin occurs automatically if
the unit switches four times in a 15-minute period. It will
remain in that state for 24 hours or until the lockin
function is disabled through provisioning. Not
coincidentally, the default threshold for 15-minute time
periods is four switches. If all four switches occur in the
same quarter-hour PM period, a threshold crossing will
accompany the lockin.
Section 5, Performance Monitoring Parameters, for the
minimum, maximum, and default parameters.
3.66: T-LBCN
Vol. ll, Page 480.3-39