This MIB contains information that must be supported by all HMS network elements, including but not limited to, transponders, line monitors, amplifiers, fiber nodes, and power supplies. The Property MIB defines the 'properties' that may be associated with each parameter. This MIB is defined so that these 'properties' may be applied to any parameter, because the index to the MIB is the object identifier of the parameter. The purpose of a 'property' is to provide a mechanism to manage alarm thresholds. It is not the responsibility of the transponder to check for violation of the above recommendations. The element manager is responsible for checking alarm limit values. Entries in the property table are specifically for 'analog' parameters. The discrete property table is used to monitor other parameters. Each property entry has four alarm threshold levels that may be established. These are: LOLO Alarm threshold for the extreme low condition. LO Alarm threshold for the low condition. HI Alarm threshold for the high condition. HIHI Alarm threshold for the extreme high condition. In addition, there is a 'Deadband' setting which applies to all alarm thresholds. After an alarm occurs, the parameter value must pass back over the alarm threshold by this amount for the alarm condition to be cleared. This Deadband is smaller than the distance between any two alarm thresholds to avoid indeterminate states. Alarm detection for each threshold is controlled by a specific bit in the alarmEnable variable for the entry. Alarm detection is active when the corresponding bit in alarmEnable is enabled. When an alarm condition is detected, in either the propertyTable or the discretePropertyTable, an entry is created in the alarm log ( see HMS023Rx.MIB ) and an alarmEvent SNMP trap sent by the transponder/agent. NOTE Parameters which do not 'exist' must NOT have properties that are accessible. For example, in the HMS027 MIB (SCTE 38-4), the MIB object psOutputPowerSupport indicates whether or not the power supply supports the psPowerOut object. If the psPowerOut object is NOT supported, then the properties normally associated with the psPowerOut object must not be accessible. Some devices only require 16 bit integer or smaller and therefore only support 16 bit (or smaller) values. Values outside of the supported range will return a bad value error.