The value of tmnxPkiCertExpWarningHours specifies the time period (in hours) at which the system will generate the tmnxPkiCertBeforeExpWarning trap for all in-use certificates before expiration. If tmnxPkiCertExpWarningHours is configured, the system will also generate the tmnxPkiCertAfterExpWarning trap when a certificate expires. If both tmnxPkiCertExpWarningHours and tmnxPkiCertExpWarningRepeatHrs are configured to 0, the system will only generate the tmnxPkiCertAfterExpWarning trap when a certificate expires. A value of -1 indicates that tmnxPkiCertExpWarningHours is not configured. In this case, the system will not generate a trap even when a certificate expires. The objects tmnxPkiCertExpWarningHours and tmnxPkiCertExpWarningRepeatHrs have to be set together for the specific action to be performed.