CISCO-ENTITY-SENSOR-MIB

CISCO-ENTITY-SENSOR-MIB is virtually identical to ENTITY-SENSOR-MIB.

Example SNMP walk

CISCO-ENTITY-SENSOR-MIB::entSensorType.4023 = INTEGER: celsius(8)
CISCO-ENTITY-SENSOR-MIB::entSensorScale.4023 = INTEGER: units(9)
CISCO-ENTITY-SENSOR-MIB::entSensorPrecision.4023 = INTEGER: 0
CISCO-ENTITY-SENSOR-MIB::entSensorValue.4023 = INTEGER: 23
CISCO-ENTITY-SENSOR-MIB::entSensorStatus.4023 = INTEGER: ok(1)
CISCO-ENTITY-SENSOR-MIB::entSensorValueTimeStamp.4023 = Timeticks: (2885003886) 333 days, 21:53:58.86
CISCO-ENTITY-SENSOR-MIB::entSensorValueUpdateRate.4023 = INTEGER: 30 seconds
CISCO-ENTITY-SENSOR-MIB::entSensorMeasuredEntity.4023 = INTEGER: 0

CISCO-ENTITY-SENSOR-MIB::entSensorType.4002 = INTEGER: truthvalue(12)
CISCO-ENTITY-SENSOR-MIB::entSensorScale.4002 = INTEGER: units(9)
CISCO-ENTITY-SENSOR-MIB::entSensorPrecision.4002 = INTEGER: 0
CISCO-ENTITY-SENSOR-MIB::entSensorValue.4002 = INTEGER: 1
CISCO-ENTITY-SENSOR-MIB::entSensorStatus.4002 = INTEGER: ok(1)
CISCO-ENTITY-SENSOR-MIB::entSensorValueTimeStamp.4002 = Timeticks: (18642) 0:03:06.42
CISCO-ENTITY-SENSOR-MIB::entSensorValueUpdateRate.4002 = INTEGER: 0 seconds
CISCO-ENTITY-SENSOR-MIB::entSensorMeasuredEntity.4002 = INTEGER: 0

Implementation

Sensor Description

As default Observium will use entPhysicalName to describe the sensor if it exists, if it doesn't exist, Observium will use entPhysicalDescr. Observium does this because entPhysicalName is normally a more succinct description, whereas entPhysicalDescr is often either very long or doesn't uniquely identify the sensor in the system.

This behaviour is known to be reversed on IOS XR.

entSensorType

entSensorType specifies the sensor measurement type (taken from SensorDataType) and is mapped directly to a sensor type in Observium. Text in bold specifies what the supported sensors are mapped to in Observium. This variable is set by the agent at start-up and the value does not change during operation.

other(1) - a measure other than those listed below
unknown(2) - unknown measurement, or arbitrary, relative numbers
voltsAC(3) - electric potential Voltage
voltsDC(4) - electric potential Voltage
amperes(5) - electric current Current
watts(6) - power
hertz(7) - frequency Frequency
celsius(8) - temperature Temperature
percentRH(9) - percent relative humidity Humidity
rpm(10) - shaft revolutions per minute Fanspeed
cmm(11) - cubic meters per minute (airflow)
truthvalue(12) - value takes { true(1), false(2) }
specialEnum(13) - value takes user defined enumerated values
dBm(14) - dB relative to 1mW of power

entSensorScale

This variable indicates the exponent to apply to sensor values reported by entSensorValue. Observium uses this value along with entSensorPrecision to define the divisor and multiplier used on the raw entSensorValue. This variable is set by the agent at start-up and the value does not change during operation.

Valid values are below:

yocto(1), -- 10^-24
zepto(2), -- 10^-21
atto(3), -- 10^-18
femto(4), -- 10^-15
pico(5), -- 10^-12
nano(6), -- 10^-9
micro(7), -- 10^-6 Divisor 1000000
milli(8), -- 10^-3 Divisor 1000
units(9), -- 10^0
kilo(10), -- 10^3 Multiplier 1000
mega(11), -- 10^6 Multiplier 1000000
giga(12), -- 10^9 Multiplier 1000000000
tera(13), -- 10^12
exa(14), -- 10^15
peta(15), -- 10^18
zetta(16), -- 10^21
yotta(17) -- 10^24

entSensorPrecision

This variable indicates the number of decimal places of precision in fixed-point sensor values reported by entSensorValue. It is used alongside entSensorScale to define the multiplier/divisor used by Observium. This variable is set by the agent at start-up and the value does not change during operation.

When in the range 1 to 9, entSensorPrecision is the number of decimal places in the fractional part of an entSensorValue fixed-point number. When in the range -8 to -1, entSensorPrecision is the number of accurate digits in an entSensorValue fixed-point number.

For example, a temperature sensor that can measure 0 to 100 C in 0.1 increments, +/- 0.05, would have an entSensorPrecision of 1, a entSensorDataScale of units(0), and an entSensorValue ranging from 0 to 1000. The entSensorValue would be interpreted as (degrees C * 10).

entSensorType.1 = celsius(8)
entSensorScale.1 = units(9)
entSensorPrecision.1 = 1
entSensorValue.1 = 230

The example above would return a divisor of 10 (from precision 1) and a multiplier of 0 (from unit scale). The value is therefore 230 * 0 / 10 = 23C

entSensorType.1 = amperes(5)
entSensorScale.1 = milli(8)
entSensorPrecision.1 = 1
entSensorValue.1 = 500

The example above would return a divisor of 10 (from precision 1) and a divisor of 1000 (from milli scale) creating a divisor of 10000. The value is therefore 500 / 10000 or 0.05A or 50mA.

entSensorValue

entSensorValue This variable reports the most recent measurement seen by the sensor.

To correctly display or interpret this variable's value, you must also know entSensorType, entSensorScale, and entSensorPrecision.

entSensorStatus

entSensorStatus indicates the operational status of the sensor.

ok(1) means the agent can read the sensor value.
unavailable(2) means that the agent presently can not report the sensor value.
nonoperational(3) means that the agent believes the sensor is broken. The sensor could have a hard failure (disconnected wire), or a soft failure such as out-of-range, jittery, or wildly fluctuating readings.

entSensorMeasuredEntity

This object identifies the physical entity for which the sensor is taking measurements. For example, for a sensor measuring the voltage output of a power-supply, this object would be the entPhysicalIndex of that power-supply; for a sensor measuring the temperature inside one chassis of a multi-chassis system, this object would be the enPhysicalIndex of that chassis.

Observium currently stores but doesn't use this data.