We previously discussed the challenges of extending the life of a legacy network and the role our communications modules can play in keeping a legacy network up and running. But what happens when your legacy network really is at the end of its life? What’s next?

Amid all the planning for updating the network, it’s easy to get talked into a standard IT solution for networking, even for an OT application.  But what if there was a built-for-purpose Ethernet I/O solution?

For those of you that have used a Phoenix Digital communications solution to connect newer head-end PLCs like ControlLogix to legacy networks like remote I/O, did you know that when it’s finally time to replace the remote I/O with a newer PLC, Phoenix Digital has a drop-in solution, again, built for OT?

A major hurdle with newer managed switches is that they require laser-optimized fiber cable, like OM3 and OM4. This is a costly endeavor, not only requiring the purchase of more expensive cable but also entailing the cost of ripping out the old cable and installing the new. Updated cable then requires re-architecting the entire network, adding more cost, time and complexity to the migration.

The pandemic hit all industries hard and was particularly difficult for companies and operations running on legacy control networks.

First, the economy crashed, and businesses didn’t have the income to fund a network update. Now, with the economy revving back up, businesses are busy playing catch up and can’t afford the downtime necessary for an update.

Those, in fact, are the two main reasons most operations put off updating their legacy control networks:

• Lack of capital funding
• Lack of time to complete the upgrade

All sorts of applications face these challenges. Take, for instance, a nuclear power plant in California. Because the operator planned to close the plant in five years, it made no sense to pay the high cost of removing the existing cable and rewiring all the I/O.

High availability is of critical importance in a wide range of demanding industries, like oil and gas, mining and water and wastewater, which require 24/7/365 operation.

The control networks used in these applications don’t have the luxury of waiting seconds – or even milliseconds – to recover from a fault. They require a seamless approach that a REP or typical ring can’t produce.

A solution often used in these applications is parallel redundancy protocol (PRP). To employ the protocol, two identical LANS are created, both sending duplicates of the same packet. Whichever packet reaches the device first is accepted, while the second is discarded. This system ensures true redundancy if either LAN should experience a fault.

However, parallel redundancy protocol presents at least one downside: cost. Implementing PRP requires the creation of a duplicate LAN, adding considerably to the cost of any network. It also requires specialized equipment to complete the connections, if the communications modules don’t have PRP built in, further adding to both PRP’s cost and complexity.

Imagine your worst nightmare for your managed switch network: an outage on the weekend when IT support is not immediately available. Or simply imagine an outage on your average way-too-busy day when IT support is still hard to come by.

Too Much Complexity

The complexity presented by managed switch networks is a constant source of concern for OT staffs. The command line interface that’s required for each switch introduces numerous problems, including the possibility of error and the need for testing each line of code with each change. There are also security concerns – If you can manipulate the coding, that means someone else could, someone with far less benign intentions.

And then there are the regular software updates and security patches required to keep managed switch networks in working order. All these concerns complicate daily operations for OT staffs that simply want to keep production running.

We previously discussed device rings as a possible communications networking solution for applications like:

• Networking devices within a control panel
• Networking between control panels
• Networking in an MCC and between MCC Sections
• Networking devices outside the cabinet
• Networking zone to zone

This month, we’ll review switch rings as a possible solution for these situations.

Switch rings, which are basically a ring of switches, include REP, MRP, Hirschman HiPER ring and Moxa Turbo ring. These require managed switches that can be configured for specific switch ring technology. Depending on the setup, convergence times can vary from 20ms to 300ms:

• REP: 20-80ms
• MRP, Hirschman HIPER ring: 80ms-300ms
• Moxa Turbo ring: <20ms

At approximately 51 miles long, the Panama Canal is considered one of the wonders of the modern world.

It’s also controlled using Phoenix Digital’s OCR communication modules.

Our modules play an integral role in the operation of the canal locks, both the original locks and the new locks opened in 2016. The OCR is part of the system that controls the level of water in the locks, filling and draining the massive receptacles as ships proceed up and down the canal.

As a result, they also help manage the level of Gatun Lake, which is at the center of the canal system.

The Locks and Facilities Engineering Division of the Panama Canal decided to go with Phoenix Digital communication modules when it began making the switch from data highway remote I/O to Ethernet.

We previously discussed various applications for fault-tolerant networks, such as:

• Networking devices within a control panel
• Networking between control panels
• Networking in an MCC and between MCC Sections
• Networking devices outside the cabinet
• Networking zone to zone

Let’s take a closer look at device rings as one potential solution for at least some of these applications.

The Phoenix Digital communication module offers an easily deployed, redundant, secure fiber ring network to its customers, which configures with a single DIP switch and no software.  Within the topic of security, as with many communication products, the Phoenix Digital modules have a multilayered approach that is baked into the module.  This requires almost no action by the customer as it is integral to every product.

Fault-tolerant, redundant, resilient industrial networking is critical in a wide range of applications.

Some of the more common uses for industrial networking include:

• Networking devices within a control panel
• Networking between control panels
• Networking in an MCC and between MCC Sections
• Networking devices outside the cabinet
• Networking zone to zone

The methods for creating fault-tolerant networking are nearly as numerous as the applications. Here’s a rundown of some of the most prevalent industrial networking solutions.

Device Level Rings

Device level rings, or DLR, connect Ethernet from one device to the next in a ring. Non-DLR devices must use an E-TAP (a two-port switch) or another switch with DLR embedded to connect. In a ring, communications are maintained when any one line or device fails, with a 3ms convergence time.

Phoenix Digital’s fiber optic communication modules provide advanced, interactive, system-level diagnostics. (Fiber modules must be ordered with the “-D” option for interactive diagnostics.) These diagnostics may be accessed thru the PLC user program (1746 and 1756 plug-in modules) or via discrete contact outputs (standalone, DIN-rail/panelmount fiber optic module) to validate network integrity and assist in troubleshooting network problems, such as:

• Detect and locate fault conditions throughout the network
• Verify fault management and overall network integrity
• Simulate network fault conditions
• Trap-and-hold intermittent failure conditions

We’re pleased to announce our move to the Knoxville, TN, location of Softing Inc. Softing AG is the parent company of both Softing Inc. and Phoenix Digital.

The integration of our offices puts Softing’s technical expertise literally at our fingertips. We will have easy access to 60 engineers and other technical resources to expand our capabilities to produce the high-quality products that our customers have come to rely on.

Our new address is 7209 Chapman Highway, Knoxville, TN 37920. Our new phone number is 865-251-5252.

Several prospective clients have asked about DLR (device level rings) and how they compare to our communication modules. 

Some Background

The Phoenix Digital products are smart, purpose-built I/O switches, specifically designed to operate for the industrial automation I/O layer and can be used with any automation supplier.  DLR requires special gateways (called ETAPs) to support non-DLR devices.

DLR is resilient, not redundant. The Phoenix Digital communication system, on the other hand, is a resilient and fully redundant network, deploying two independent channels of communication running hot, synchronized and in opposing directions.

Motor control centers (MCCs) provide a great deal of convenience for modern plants and factories. A wide range of motors, including variable speed drives, overload relays and starters, can all be managed from a central location.

MCCs are generally available in two types:

• Standard, which is hard-wired
• Intelligent, which is Ethernet-enabled

It’s generally accepted that intelligent MCCs require the highest level of managed switch technology to properly operate. This creates serious challenges for the average maintenance staff, which doesn’t have the IT background necessary to maintain the switches.

Knoxville, TN, August, 2019 - Softing AG has acquired the assets of Phoenix Digital Corporation (PDC), a provider of secure industrial fiber optic communication products. The business will be operated by Online Development Inc.

"Phoenix Digital's secure fiber optic modules are a great addition to Softing Industrial's portfolio of IoT communications products, expanding the technologies offered and the industries served," said Dr. Wolfgang Trier, CEO of Softing AG. Softing is expecting the acquisition to contribute additional revenue of up to EUR 3 million annually once integrated in the Softing product portfolio.

In the early 2000s, officials decided to create the East End Tunnel in Louisville, KY, which would allow state highway 841 to run under a sensitive historic site in the city. The project was part of a larger $2.3 billion project to improve various crossings over the Ohio River between Kentucky and Indiana.

As officials planned the 1,700 feet of tunnel, some challenges quickly became apparent.

For one thing, the project required a new communication network to tie together the tunnel’s traffic control system as well as the system that controlled the air ventilation fans in the tunnel.

At Phoenix Digital, we think things like network communications do not always need to be complicated. Sometimes enough is all you need.

With that in mind, what the group here at Phoenix Digital spends a great deal of time working on and talking about is how to make communications easy, reliable, secure, easy, fast, fault tolerant, and easy. Basically, we want to give the customer as much capability as possible, but we want to deploy that technology quickly and easily. This is what we do.