UA PubSub Model (uadp)

Unified Architecture topics related to OPC UA Specification, compliant behavior and any technical issues of OPC UA, like Security, Information Model, Companion Specs DI, PLCopen, ADI, ...

Moderator: Support Team

Post Reply
Jr. Member
Jr. Member
Posts: 1
Joined: 15 Mar 2019, 09:55

UA PubSub Model (uadp)

Post by magic337 »

Hello dear community

I would like to ask how it is posscible to implement the pubsub model bettwen the embedded WinCC 7.4 UA server V1.0 and a UA Client.

The task is just to publisch online data for a client. It is written that existing UA protocol already includes a subscription model that allows the server to publish notifications of data changes.

what could be a solution since both software are complete and certified. There is an UADP multicast approach but how to configure the server at least?

thank you in advance

best regards


User avatar
Support Team
Hero Member
Hero Member
Posts: 2550
Joined: 18 Mar 2011, 15:09

Re: UA PubSub Model (uadp)

Post by Support Team »


you are mixing up two things here.
1) OPC UA ClientServer (has subscription, can monitor items on change, uses TCP conneciton)
2) OPC UA PubSub (has predefined dataset, may cyclically broadcast dataset, typically independenlty of change, uses UDP multicast)

The products you are refering can do 1) and the Client can create a subscription in the Server and the Client can add items to be monitored to that subscription, and the server will notify (publish) on change for those monitored items. and for this operation the products are certified. However this has nothing to do with 2), which is a different mechanizm for different use case, and probably not supported by the two products you are refering.
Best regards
Unified Automation Support Team

Post Reply