Inquiry of Data Exchange (regarding OPC, Edge Link, etc)

Questions regarding installing, running and configuring UaGateway.

Moderator: uagateway

Post Reply
Jr. Member
Jr. Member
Posts: 1
Joined: 20 Feb 2020, 05:15

Inquiry of Data Exchange (regarding OPC, Edge Link, etc)

Post by qpqp403 »

Hello members,

Currently I am facing technical difficulty on data exchange that I need to ask your kind support.
Our data flows as described below, and the requirement is
"there must not be any request from Data Exchanger to OT Componenet."

PLC or SCADA --> OT Component --> Firewall --> Data Exchanger --> Firewall --> Cloud

With my knowledge, however, OT component cannot push data to Data Exchanger without getting any request.
1. OPC UA does not support pub/sub function at the moment. (I believe it is under developing).
2. Edge Link of Advantech is also working with Data Polling method which requires request and response to exchange data.

I would really appreciate if anyone shares the idea to resolve my difficulty.
Thanks in advance.

User avatar
Support Team
Hero Member
Hero Member
Posts: 2666
Joined: 18 Mar 2011, 15:09

Re: Inquiry of Data Exchange (regarding OPC, Edge Link, etc)

Post by Support Team »


OPC UA has a solution to "overcome" firewalls blocking inbound trafic. The mechanizm is called "ReverseConncet".

Typically your data source (the PLC/OT Component) will be UA-Server. and typically the DataExchanger will be the UAClient, and actively calling/connecting to the OT-Server. Unfortunately the Firewall will typically block such inbound traffic. However the "ReverseConnect" feature allows the UA-Server to establisch the connection to the UA Client (assuming both components support this feature). With that the connection establishment is initiated from the OT Component and such outbound connection will go through your firewall.

UaGateway from Unified Automation supports such "ReverseConnect" feature (same as UaExpert).
Best regards
Unified Automation Support Team

Post Reply