Over the course of numerous automation network infrastructure related projects, I’ve experienced the same scenario almost every time. We develop a solution to fit a client’s needs, while being mindful to keep costs down. Yet, if the switch manufacturer isn’t top of the line, the client will demand a design change—so the expensive high-end switches are implemented. While there are plenty of scenarios where switches like these are needed, automation needs to embrace some alternatives in the market.
As we all have experienced, the hardware we deal with is not always the most cutting edge, and even if it is, there is always some kind of limiting factor. In networking, the factor is typically the speed at which data can be transmitted. Some terms you may be familiar with is Megabit (also referred to as Fast Ethernet) and Gigabit, which respectively refers to traffic traveling at 100 Mbps or 1000 Mbps (or 1 Gbps). Many times, automation equipment is not capable of communicating at speeds higher than Megabit. Though most switches by default are capable of communication at Gigabit or faster, speed isn’t necessarily something to be focused on when picking out equipment. Your speed should be determined by the network you are implementing, as there isn’t one solution that fits all needs. If your network is a full-blown automation network, that has numerous varieties of skids, equipment, computers, and servers that all need to be connected, then you need to make sure you have a Gigabit switch. However, if you are designing a small private network, with a controller and a couple of remote IO’s, then you probably do not need speeds as high as Gigabit. Due to the cost of industrial networking equipment, it may be worth the cost savings to buy a less expensive switch and a spare, as opposed to an overpowered switch that will never be used to its full potential. You don’t need a Ferrari to drive down the driveway to get your mail.
Another consideration when choosing networking equipment is the personnel on hand that will be tasked with maintaining the system. Often, the system needs to be easily maintained by teams without the networking expertise to successfully troubleshoot networking issues. One method is to have the cream of the crop switches, maintain proper backups, create SOPs for people to follow to restore a configuration, and then have them move ethernet plugs from a broken switch to a new switch in the exact same order. This isn’t a bad solution, but it relies on regular backups, testing of the backups, can be prone to errors, and may force unqualified people to deal with issues they are not able to resolve. Instead, what if an unmanaged switch was used? It still enables the communications needed, but if things go wrong you can swap it out with any unmanaged switch, plug it in, and are back running in minutes. This is a solution that is often overlooked due to marketing around managed switches. If advanced features won’t be implemented, is it worth the added complication? You could buy a smart phone, but if your only goal is to make phone calls maybe a normal phone would suit your needs.
The last network consideration is usually where decisions are made, with dollars and cents. It can be hard to justify the need for more complicated and costly switches when the project requirements simply don’t necessitate them. Some of these brands have their own support and userbase who can help maintain them as well. These companies offer the same functionality in their equipment as the big names, but without paying the same price. For the cost of a single well-known brand of switch that might be overpowered for the solution, you can possibly outfit the whole network with other lesser known brands and still have some budget remaining. At the end of the day both a Rolex and Timex still tell time.
So next time you are tasked with working on a project with networking and are determining requirements, ask yourself, “Is this a network need or a network nicety?”
Josh Glass is Lead Automation Engineer/Network Specialist at Panacea Technologies, a certified member of the Control System Integrators Association (CSIA). For more information about Panacea, visit their profile on the Industrial Automation Exchange.