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OPC Parameters

OPC Parameters

Owned by dominik.kurfner (Unlicensed)
Last updated: Jan 20, 2025 by Robert Schneider
3 min read

Name

Description

Scope

Unit

Default

Name

Description

Scope

Unit

Default

OPC.GroupAddressType

Specifies the format that is used to map KNX group addresses to server item IDs. 2Level - uses the two-level KNX group address format 3Level - uses the three-level KNX group address format.

In contrast to defined parameter within the studio, this has a crucial influence on the structure of all server item IDs.

The following examples represent the same KNX datapoint:

  • OPC.GroupAddressType: 2Level -> ITEM ID = "NETx\XIO\KNX\192.168.1.1\00/0513"

  • OPC.GroupAddressType: 3Level -> ITEM ID = "NETx\XIO\KNX\192.168.1.1\00/2/001"

2level, 3level

None

3level

OPC.PrefixedItemID

Specifies whether the leading "0"-characters shall be added to server item IDs.

  • ON: leading "0"characters are added to the item IDs of KNX group addresses

  • OFF: the item IDs of KNX group addresses do not contain leading "0"-characters

This parameter has crucial influence on the structure of all server item IDs.

The following examples represent the same KNX datapoint:

  • OPC.PrefixedItemID: ON -> ITEM ID = "NETx\XIO\KNX\192.168.1.1\00/2/001"

  • OPC.PrefixedItemID: OFF -> ITEM ID = "NETx\XIO\KNX\192.168.1.1\0/2/1"

ON, OFF

None

ON

OPC.AsyncTimeout

Specifies the timeout value for asynchronous OPC queries. If no answer to an OPC query is received within this time interval, the quality of all queried datapoints will be set to UNCERTAIN.

1 – 60

s

5

OPC.AsyncReadFromDevice

Specifies whether the response data of the asynchronous OPC value read queries ("READ") shall be read from the server's data base or directly be retrieved from the field device.

  • ON - the field devices are queried

  • OFF - the values are read from the server's data base

ON, OFF

None

OFF

OPC.AsyncRefreshFromDevice

Specifies whether the response data of the asynchronous OPC value refresh queries ("REFRESH") shall be read from the server's data base or directly be retrieved from the field device.

  • ON - the field devices are queried

  • OFF - the values are read from the server's data base

ON, OFF

None

OFF

OPC.ShowETSStructure

Specifies whether to show an ETS like structure within the server item tree.

  • ON - shows the ETS-like structure

  • OFF - shows the NXA-like structure

ON, OFF

None

OFF

OPC.QualityForValueNotSet

Specifies which OPC Quality value shall be used for item values that are not yet set.

UNCERTAIN, BAD, NOT_CONNECTED

None

UNCERTAIN

OPC.Delimiter

Specifies which delimiter shall be used for the item IDs within the server item tree.

String (note: " is not allowed)

None

\

DEPRECATED PARAMETERS – Will be removed in future releases.

OPC.RefreshOnEqualValue

Specifies whether OPC "OnDataChange" events are generated by incoming values from the field level even if the values are unchanged.

  • ON - the "OnDataChange" of events will be generated

  • OFF - the "OnDataChange" of events will be generated only with changes of value

Example:
If the server receives two KNX telegrams with same value and same address (IP + KNX group address) and the option "OPC.RefreshOnEqualValue" is set to "OFF", the OPC "OnDataChange" event is generated only for the first telegram, since the second telegram does not cause a change of value of the datapoint. If this option is set on "ON", then two OPC "OnDataChange" events are generated.

ON, OFF

None

ON

OPC.AllValuesValid

If set to "ON", server items always have the quality "GOOD", even if their quality is "BAD" or "UNCERTAIN". This option can be used for limited OPC clients that are not aware of OPC qualities other than "GOOD".

ON, OFF

None

OFF

Article applies to the following products:

  • NETx BMS Platform

  • NETx Multi Protocol Server

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