Creating SNMP GET element

Owned by Vasily T.
Last updated: Sept 05, 2024 by Vladimir Tayzhev
4 min read



There's no direct limit of SNMP Trap elements in the system.

But there's a limit for overall elements in the system. Please use the table from "Comparison chart: Master modules", "Comparison chart: PDUs", horizontal field "Max. amount of elements:".

Introduction

All Vutlan monitoring systems support SNMP GET element,.

Virtual sensor "SNMP Get" is used to read data from external equipment via SNMP PDU GET (v1, v2c, v3). The "SNMP Get" sensor can be analog or discrete type. The analog sensor interprets the value read by SNMP as a decimal number, extraneous characters (if they are in the data line) are discarded. The discrete sensor compares the read value with the given sample (called "Normal value"), and if the sample is contained in the data line, then the element takes the state "normal", if the sample is not in the line, it takes the state "alarm".

How to create an SMP GET element

To create an "SNMP Get", press add button " Unknown Attachment " inside "System tree" menu. Then choose "SNMP Get (analog)" or "SNMP Get (discrete)". A modal window will appear:

Click on the "SNMP Get (analog)". SNMP Get element form will be opened:

Fields in the form available for change:

#

Name

Description

#

Name

Description

1

Name

Created element name

2

User-defined type

Defines the icon to be displayed in the "System tree"

3

Units of measurement

The unit of measure in which the value is displayed in the "System tree"

4

Minimum value

Determines the minimum measurement range, when the value is out of range, the sensor goes into the "Not connected" state

5

Maximum value

Determines the maximum measurement range, when the value is out of range, the sensor goes into a "Not connected" state

6

Alarm and warning levels

Defines the alarm and warning thresholds, as for other sensors, see Sensor configuration

7

Hysteresis

Option of setting the hysteresis state, see Sensor configuration

8

Expression

Function of the form f (x). The default value for the sensor is equal to the measured value: "x", ie corresponds to the expression "x". To calculate the indirect value of the sensor is possible to use an arbitrary expression, which are permissible "(", ")", as well as:

  • operators: "+", "-", "*", "/", "%" (remainder of the division), "^" (exponentiation);

  • functions: "abs","sqrt","exp","ln","log","sin","cos","tan","asin","acos","atan";

  • constants: "pi" (3.1415926...), "e" (2.7182818...);

  • point is used as a decimal separator (3.14).

        For example: "0.1*x+0.5"



Click on the "SNMP Get (discrete)". SNMP Get element form will be opened:

Fields in the form available for change:

#

Name

Description

#

Name

Description

1

Name

Created element name

2

User-defined type

Defines the icon to be displayed in the "System tree"

3

Current state

The state of the element calculated according to behavior

4

Current value

The value of the element, does not depend on the behavior

5

Value string

Data string read by SNMP GET

6

Behavior

Normal or reverse behavior

7

Normal value

Sample substring, if the substring is contained in the data line, then the element takes the state "normal", else it takes the state "alarm" (according to behavior)


The "Additional" tab contains SNMP connection settings for SNMP version 1 or 2c:

Fields in the form for SNMP version 1 or 2c:

Name

Description

Name

Description

Status

Status of the connection

SNMP server

SNMP agent address

SNMP port

SNMP agent port

SNMP version

The version of protocol, 1 or 2c

Community

Agent read community

Polling period

Period sending SNMP Get request

OID identifier

The object identifier in the remote system, digital-only form


The "Additional" tab contains SNMP connection settings for SNMP version 3:


Fields in the form for SNMP version 3:

Applicable for Vutlan for VT335i, VT335t, and VT960i series.

Name

Description

Name

Description

Status

Status of the connection

SNMP server

SNMP agent address

SNMP port

SNMP agent port

SNMP version

The version of the protocol, 3

USM user

The security user name

Security level

The security level may be:

  • no auth, no priv - No Authentication, No Privacy

  • auth, no priv - Authentication only

  • auth, priv - Authentication and Privacy encryption

Auth algorithm

The authentication type: MD5 or SHA

Auth password

The authentication password. This must be at least eight characters in length.

Private algorithm

The type of privacy: DES or AES

Private password

The privacy password. This must be at least eight characters in length.

Polling period

Period sending SNMP Get request

OID identifier

The object identifier in the remote system, digital-only form