Revision as of 05:36, 24 November 2025

Glossary

SMI (Structure of Management Information): Defines the rules for objects in MIB.
MIB (Management Information Base): A database that contains information about managed devices.
OID (Object Identifier): A unique numerical identifier given to each object.
NMS (Network Management System): Used to receive and send information from SNMP agents.
GET (gettable)/Walk (walkable): Objects that can be queried using SNMP GET and WALK commands (read-only).
SET (settable): Objects that can be modified from NMS (read-write).
Trap: A message sent by the SNMP agent (AQue) to the NMS.
Alarm: Status messages sent from the SNMP agent to the NMS.
Varbinds (Variable Bindings): Additional information included in the alert sent from the SNMP agent.

Note: Not all objects in the MIB tree are SET-enabled due to risk of system reboot or instability. This functionality can be enabled on customer request. Objects in the *modules* branch are SET-enabled as threshold adjustments help in troubleshooting.

1. Summary

This document explains the purpose and layout of the PLC MIB, including:

HVAC and Battery MIB structures
Trap OIDs and Varbinds
Event status and severity information
Floating multiplier usage
SNMP integration from the AQue frontend

2. Scope

This document is intended for engineers, technicians, IT professionals, and NOC teams monitoring systems through SNMP.

It is assumed that users understand:

SNMP Protocol
SNMP monitoring software (NMS)
MIB loading / walkthrough
SNMP configuration from AQue

3. Structure of PLC MIB

PLC MIB begins with:

iso.org.dod.internet.private.enterprises.sitelogic OID: 1.3.6.1.4.1.45391

Explanation:

1 = ISO
3 = ORG
6 = DOD
1 = Internet
4 = Private
1 = Enterprises
45391 = PLC Enterprise

After the PLC Enterprise ID, the MIB splits into four branches:

info
settings
modules
systemNotifications

3.1. info Branch

The info branch contains:

systeminfo
hardwareInfo

3.1.1. systeminfo Branch

The systeminfo branch contains:

site
system
version
network

site (SET-enabled): Gives site name, ID, address, operator, latitude, longitude.

system (GET/WALK): Shows uptime, memory, and storage.

version (GET/WALK): Shows OS version, hardware model, software/hardware versions.

network (GET/WALK): Displays IP address, subnet mask, and gateway.

3.1.2. hardwareInfo Branch

Contains:

totalNoOfDevices
hardwareInstanceTable (GET/WALK)

hardwareInstanceTable includes:

hardwareName
hardwareStatus
hardwareType

Example: HVAC-1, HVAC-2, HVAC-3.

3.2. settings Branch

Contains:

clientSettings
dateTimeSettings
snmpSettings

clientSettings (SET): Name, username, contact.

dateTimeSettings (SET): Device date/time, timezone, NTP server.

snmpSettings (SET): Primary/secondary IPs & ports, server counts, agent ports, etc.

3.3. modules Branch

Contains two subbranches:

cooling
energy

3.3.1. cooling Branch

Contains:

sitelogicModuleHvacMIB → hvac

3.3.1.1. hvac Branch

Contains three tables:

hvacHardwareInfoTable (GET/WALK)
hvacConfigurationsTable (SET + GET/WALK)
hvacAlarmTable (SET + GET/WALK)

hvacHardwareInfoTable Includes: name, description, manufacturer, serial, etc.

hvacConfigurationsTable Includes SET objects:

hvacConfigName
hvacConfigDescription
hvacConfigValue
hvacConfigHighThreshold
hvacConfigLowThreshold

hvacAlarmTable Includes SET objects:

hvacAlarmName
hvacAlarmDescription
hvacAlarmPolarity
hvacAlarmHighThreshold
hvacAlarmLowThreshold

3.3.1.2. HVAC Trap OID & Varbinds

hvacDynaNotification: OID: .1.3.6.1.4.1.45391.50.70.1.1.6.0.1; Receives HVAC traps

Varbind list:

eventSeverity
eventDescription
eventTime
eventStatus
siteName
siteId
deviceIpAddress
eventHardware
hvacIndex

3.3.2. energy Branch

Contains:

sitelogicModuleBatteryMIB → battery

3.3.2.1. battery Branch

Contains three tables:

batteryHardwareInfoTable (GET/WALK)
batteryConfigurationsTable (SET + GET/WALK)
batteryAlarmTable (SET + GET/WALK)

3.3.2.2. Battery Trap OID & Varbinds

batteryDynaNotification: OID: .1.3.6.1.4.1.45391.50.75.5.1.4.0.1; Receives Battery traps

Varbind list:

eventSeverity
eventDescription
eventTime
eventStatus
siteName
siteId
deviceIpAddress
eventHardware
batteryIndex

3.4. systemNotifications Branch

Contains:

systemNotification: OID: .1.3.6.1.4.1.45391.110.0.1; Receives system alerts such as memory full.

Varbinds:

eventDescription
eventStatus
eventSeverity
eventTime
eventHardware

Event Status Table

Value	Status
0	alarmClose
1	alarmOpen

Event Severity Levels

Level	Value
urgent	0
critical	1
major	2
minor	3
warning	4
clear	5
notification	6

4. Floating Multiplier Settings

SNMP cannot directly handle decimal values.

To handle this, PLC MIB uses two float multipliers:

Multiplier	Description
Float1 = Value × 10	For one-decimal values Objects: hvacConfigValue hvacAlarmValue batteryConfigValue batteryAlarmValue
Float100 = Value × 100	For two-decimal values

5. AQue SNMP Configuration

Steps:

Load the MIB file in your NMS.
Log in to AQue (Default: admin / password).
Go to **Settings → General → SNMP**.
Configure:

  * SNMP Agent  
  * SNMP Trap

Supported versions:

SNMP v2c
SNMP v3
Both

After configuration, perform Walk/Get from NMS to verify.

6. PLC Support

If issues remain, contact PLC Support:

24/7 Support Phone: +1 855 752 4787
Support Email: support@plcgroup.com