Software Toolbox Technical Blog

Redundancy can mean a lot of things, as discussed in our Demystifying Redundancy Blog post.  In this blog post we want to focus more specifically on one of the use cases in that blog post:  managing redundant OPC servers.  Just having two OPC servers talking to your PLC’s does not make them redundant.  Most OPC Servers don’t have built-in methods of knowing there is another redundant OPC server instance out there.

Some HMI/SCADA systems support redundancy but sometimes it involves scripting and other custom written code.   So, in many cases, you need supplemental software to manage and optimize the connections to your two OPC servers.  Your OPC client then talks to the redundancy management software as if it is the actual OPC server.

This blog post covers some of the considerations and watch outs when choosing how to manage your OPC server redundancy.  After that we will also discuss how the Cogent DataHub can help manage your redundancy to provide high availability for your OPC server communications.

I’ve heard from users new to the automation profession that it can be overwhelming to learn about the product technologies used in industrial automation alone, while also learning about the concepts, and having to deliver on the job results.  This is the the first post of our Automation 101 blog series which is designed to help professionals that are new to the industrial automation space whether at the start of their careers, or moving into the operations technology (OT) world from an IT or other background.

In this post, I am going to discuss redundancy.  The term is often used broadly, and sometimes it can be a simple application, but it can also quickly unravel into a complex discussion with lots of technical details, more than can be covered in a single blog post.   Whenever a client contacts us to discuss redundancy, there are many questions we ask to understand what redundancy means in their operation.

My focus will be on providing insight to the reasons why redundancy is used, the business factors that drive how far you go with redundancy, the types or levels found in automation systems, and considerations in the implementation of automation software systems.