NT5D11 and NT5D14 Lineside T1 Interface cards Page 233 of 906Circuit Card Description and InstallationWhen the Set Alarm command is used, a prompt appears to configure thethreshold level and duration period for alarm levels 1 and 2.The threshold value indicates the number of bit errors detected per secondthat is necessary to activate the alarm. The T1 link processes at a rate ofapproximately 1.5 mb/s. The threshold value can be set between 3 and 9 andcan be different for each alarm level. Any other value entered will cause thesoftware to display a “Parameter Invalid” message. The threshold numberentered represents the respective power of 10 as shown in Table 89.Note: The error rate threshold for a level 2 alarm must be greater (asmaller power of 10) than for a level 1 alarm.The duration value is set in seconds and can be set from 1 to 3600 seconds(1 hour). This duration value indicates how long the alarm will last. Low biterror rates (10 -7 through 10 -9 ) are restricted to longer durations since it takesmore than one second to detect an alarm condition above 10 -6. Higher biterror rates are restricted to shorter durations because the MMI error counterfills at 65,000 errors.The alarm indications (LEDs and external alarm contacts) clear automaticallyafter the duration period has expired, if the Set Clearing (S C) “Enable SelfTable 89T1 bit error rate threshold settingsAlarm thresholdbit errors per secondin power of 10Thresholdto set alarmAllowableduration periods10 –3 1,500/second 1–21 seconds10 –4 150/second 1–218 seconds10 –5 15/second 1–2148 seconds10 –6 1.5/second 1–3600 seconds10 –7 1.5/10 seconds 10–3600 seconds10 –8 1.5/100 seconds 100–3600 seconds10 –9 1.5/1000 seconds 1000–3600 seconds
