This read-write Unsigned32 sets the number of Codeword Severely Errored Seconds allowed within a rolling 1 operational hour period before the cwrTrapLink1HrThresh trap is generated, with the measurement window starting after the first operational second. An admin tunes this to control the sensitivity of the hourly severe-error alarm, distinct from the plain error-second alarm governed by cwrLink1HrESAlarmThresh. For example, an admin who has a link with occasional but tolerable severely errored seconds could raise cwrLink1HrSESAlarmThresh to avoid nuisance traps for expected conditions.