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.
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.
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.