White Papers

In-depth discussions of DataHub technology

MQTT is the protocol of choice for many industrial communication tasks, particularly in the oil and gas sector. It was developed to be efficient, quick, and secure, and it delivers on those promises. It does a good job at what it was designed for—connecting field devices to a central SCADA system and passing data between them. Read more…

Many say that you can’t have it both ways. If you want live process data from your plant, you need to compromise on cybersecurity. Or, if you want to keep your production systems as secure as possible, you need to completely lock them down―air-gap them if possible. Read more…

OPC Alarms and Events (OPC A&E) is a data communications protocol for conveying information about process alarms and events. A&E data can be used to notify operators and management of system problems and convey sequences of events to optimize operations. Read more…

With the advent of Industrie 4.0 and Industrial IoT, there has been increasing interest in connecting plant systems to cloud services. Companies seeking to gain insights into their processes can run analytics on cloud-based IoT platforms and use the results to improve performance. Read more…

A good IIoT protocol is the basis for effective IIoT data communication. Without a secure, robust IIoT protocol, data can be late, missing, inconsistent, or dangerously incorrect, leading to costly errors and wasted time. With the IIoT still in its infancy, companies have turned first to familiar, well-tested data communication and messaging protocols such as MQTT, AMQP, REST and OPC UA for an IIoT protocol. Read more…

Access your data without exposing your network. Finally, you can now share your production data, without exposing your network to attacks like WannaCry that can propagate over a VPN, and without configuring any inbound firewall ports to your OPC UA/DA Servers. Read more…

Networking OPC is challenging because it relies on DCOM. The most practical way to network OPC is to avoid DCOM and tunnel OPC. This paper explains the problems with DCOM, and why tunnelling OPC provides a more reliable, secure, and easy-to-use approach. It also covers advanced tunnelling topics such as reducing bandwidth, non-blocking tunnels, slow networks, and more. Read more…

There are a number of tunnelling products on the market. How can you know which one is best? This paper gives a clear explanation of the major approaches to tunnelling OPC, how each approach handles network issues and supports multiple connections, and what to look for regarding security. Read more…

Many OPC-based systems require high availability of source data. This is often achieved through redundancy. This paper discusses the major concepts for redundant systems, such as hot/warm/cold standby, switchovers and fallbacks, the timer pitfall, object and link monitoring, preferred sources, and others. Read more…

There are a number of ways that the Cogent DataHub can be used to implement redundancy in an OPC-based system. This document illustrates a few of the most common scenarios. Read more…

In the automation and process control world, there are two important ways to archive data: logging it to a database or feeding it to a real-time historian. Although a relational database has many advantages, this paper gives three reasons why that approach may not be sufficient. Read more…

Every once in a while we get asked: “Can I store and forward my OPC data?” A little understanding of the purpose of OPC, and how it works, should make it clear that the answer to this question is effectively “No ‘not when it comes to real-time data, anyway.” Read more…