Dialog View OPC Item

The dialog view is used for:

Configuring of:

OPC Item mapped to the MIB variable transferred using SNMP commands SET and GET

OPC Item mapped the MIB variable transferred within SNMP TRAP – the check box Notification (Use SNMP Trap) must be checked in

Configuring of OPC Item mapped to round trip time of ICMP ping for the device - the check box Heartbeat must be checked in

Assigning of:

a simulation signal to the OPC item

a constant value to the OPC item

a conversion to the OPC item

an alarm definition to the OPC item

Editing of a function(s) written in JScript:

that is used for recalculating of MIB variable value to the OPC item value when OPC clients reads from SNMP OPC server

that is used for recalculating of OPC item value to the MIB variable value when OPC clients writes to the SNMP OPC server

that are used for both reading and writing

Sending SNMP command SET or GET to MIB variable on device with defined OID

Most important parameters (if the checkbox Heartbox is not checked in ) are in the group Item properties. The Object ID is the SNMP Object Identifier for the tag. It is the specific data address for the information you are requesting from SNMP agent embedded in your manageable network device. Most MIB addresses follow an Object ID nomenclature that has a series of whole numbers separated by periods (for example: .1.3.6.1.2.1.2.2.1.7.1.). To set up the Item you have to specify its Object ID from MIB file of the device.

dvopcitem

Figure: Dialog view to define OPC items

Name

arbitrary within address space unique name of the OPC Item that does not contain spaces. It can be edited by hand, imported on line from device or off line from MIB file of a device (the characters like *, ., /, -, :, _, ;, " are not allowed).

Heartbeat
If checked in, the OPC item will on runtime contain round trip time of the ICMP ping to the device

Description

It can be edited by hand or imported from MIB file of a device

Item properties

Object ID

OID of the MIB variable from device. It can be edited by hand, imported on line from device or off line from MIB file of a device

SNMP Data Type

Type of data as can be read / written to the SNMP device

Read only - Read/Write

Access rights from OPC client to OPC server

Notification (Use SNMP Trap)

If checked in, it is supposed that MIB variable from device will be transferred within SNMP TRAP. Other way SNMP GET / SET will be used

Simulate

If checked in, instead of a MIB variable OPC item will be changed according to predefined simulation signal

Signal

Name of the predefined simulation signal

Manual

If checked in, instead of a MIB variable OPC item will have constant predefined value

Value

Value of constant predefined value

Use conversion

If checked in, predefined conversion will be applied on OPC item value by reading or writing

Name

Name of the predefined conversion

Use script

If checked in, calculations by reading / writing will be executed. Edit box is used as JScript editor with highlighted syntax. Within functions can be used global variables. The result of editing can be found in the file ServerScript.js in directory C:\Users\user\Documents\SAEAUT SNMP OPC Server\Configurations\. In case that you want to open another configuration, please back up the file first.

Generate alarms

If checked in, a preconfigured alarm definition will be associated with the OPC item.

Mess. prefix

A few OPC items can be associated with the same alarm definition. To distinguish alarm messages for distinct OPC items a message prefix can be used.

Value

Name of the preconfigured alarm definition

SNMP Value

There is possibility to verify OID on device on line and read / write values directly from configurator

GET

Value of the MIB variable will be read and show in edit box

SET

Value of the MIB variable edited within edit box will be sent to device using SNMP command SET

Remark: In case that check box Heartbeat is checked in, only Name and description has to be configured.