Operator Menu Location: Generic Hardware Operators -> Networking -> SNMP

Operator Bitmap:

Functional Description:

SNMP Broadcast operators encode their input signal x into a communication message that they broadcast over an industrial network. But, only SNMP clients "tuned" to that broadcast will actually decode the message.

The SNMP Broadcast operator has two inputs---the first, input x is the input structure. Disable Broadcast pin, if connected and true, prevent the broadcast operator for transmitting new data.

The operator has two output pins. Output Changed is goes to true when one or more members of the structure have changed until the change has been transmitted to the Agant device. Comm Timeout goes to true when the Agent does not respond within the configured Timeout period.

User-Defined Properties:

Object Name

A string label that identifies the broadcast signal. It is used to associate this Modbus TCP Broadcast operator in one schema with Modbus TCP Receiver operator(s) in other schemas.

Structure Name

Specify the name of a Structure in a libray linked to this network which describes the input data . The structure definition must contain OID addributes that specify the relationship between each structure member and a OID on the SNMP agent device. You will need the devices SNMP MIB to perform this task. The example show below is an abbreviated example for a NOVA UPS. Note that there is no requirement that OID numbers be sequential.

<LIBRARYFILE Name="NOVA UPS">
<LIBRARY Name="NOVA">

<STRUCTURE Name="BatteryStatusStruct">

<FLOAT Name="BatteryStatus" OID="1.3.6.1.4.1.27358.33.1.2.1.0" /> 1=unknown, 2=normal,3=battery low, 4= battery depleted

<FLOAT Name="SecondsOnBattery" OID="1.3.6.1.4.1.27358.33.1.2.2.0" /> Seconds running on battery

<FLOAT Name="PercentRemaining" OID="1.3.6.1.4.1.27358.33.1.2.3.0" /> Percentage charge remaining

<FLOAT Name="BatteryVoltageX10" OID="1.3.6.1.4.1.27358.33.1.2.4.0" /> Battery voltage times 10

<FLOAT Name="BatteryTempInC" OID="1.3.6.1.4.1.27358.33.1.2.5.0" /> Battery temperature in degrees C

<FLOAT Name="MinutesRemaining" OID="1.3.6.1.4.1.27358.33.1.2.6.0" /> Minutues remaining until depleted

<STRUCTURE>

<LIBRARY>

<LIBRARYFILE>

Public Community

SNMP has a primitive security mechanism that requires a Public Community name to access readable OIDs on the Agent device. This must be the same name as is configured in the Agent device.

Private Community

SNMP has a primitive security mechanism that requires a Private Community name to access writable OIDs on the Agent device. This must be the same name as is configured in the Agent device.

Timeout

The number of milliseconds to allow for a response.

Period

The number of milliseconds between transmissions.

Write on Change

When checked, causes the data to be transmitted when a member of structure has changed even if the Period value since the previous transmission has not elapsed.Show Disable Broadcaster.

Show Comm Timeout Pin

Determines whether the Comm Timeout pin is visible.

Show Disable Broadcaster

This property determines if the disable broadcaster pin b is visible in the schema diagram. Design Pad issues a warning upon processing the schema when the pin is visible but not connected. The warning message is not issued when the pin is not visible (when this property is not checked). When the pin is low broadcasting of the data ceases.

Show Changed Pin

Determines whether pin Changed pin is visible.

Show Comm Timeout Pin

Determines whether the Comm Timeout pin is visible

Comments: None

See Also:
SNMP Receiver

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