Something Old, Something New

Connecting computing devices with serial networks dates back to the early days of computer use in manufacturing. Even though Ethernet has been around about as long, engineers have been deploying it for only a short period of time.

If there is one thing that everyone seems to agree on, it is that things change slowly in manufacturing. This leads to a conclusion that there must be numerous devices with only serial connections that engineers and Information Technology (IT) professionals would love to connect to their Ethernet networks.

Joel Young, vice president of innovation, Digi International Corp. (, a Minnetonka, Minn., network solutions supplier, puts a somewhat different spin on this issue. He uses the phrase, “serial to Internet protocol (IP)” connectivity. “This enables companies to leverage many of the devices that they already have and put them on their newer networks.”

Networking is all about moving information, so it should be no surprise that applications requiring rapid information updates would be primary users of this technology. In fact, Young states, “The biggest applications that we see involve the use of radio frequency identification (RFID).” This includes uses such as logistics, warehousing and arrival bays, plus other places to apply automation systems, such as in restaurant kitchens, he notes. “These are places where you don’t have lots of cable drops. But RFID is the big kicker. People are looking for ways for improved inventory management. ”

Young points out that suppliers have done a lot of work on the reader and tag technology for RFID, and they are working on reading standards and the cost of tags. “But all of the readers have serial ports. Serial networks are not capable of long distances. So how are users going to network them?”

Next up: wireless

Many of the applications for these serial-to-IP devices involve retrofitting legacy systems. The plant Ethernet backbone may not be extended to all locations, yet. Adding the cost of running network cables, especially in a large warehousing application, may make the project cost prohibitive. According to Product Manager Mike Kuch, of Lantronix (, an Irvine, Calif., manufacturer of networking devices, this is where the next advancement of serial-to-IP will fit in—wireless.

“The big thing going on currently is moving serial to IEEE 802.11 wireless,” states Kuch. “With the build-up of 802.11 wireless infrastructures, it is becoming easier to install an 802.11 wireless device. Wireless connectivity also allows for devices that were not connected in the past because it was too difficult to get a Category 5 Ethernet cable to them, to be put onto a network. This is a very exciting time with all of these new opportunities.”

Engineers may have reservations about adding yet another type of device to the factory floor environment. This essentially IT technology must be proven to stand up to the rigors of manufacturing. It must also be easy enough to set up and maintain that busy electricians and maintenance technicians can install and troubleshoot.

Digi’s Young responds to this challenge, “Future applications will be expanded to serial-to-WiFi (for Wireless Fidelity, the popular name for IEEE 802.11 wireless networking). The key here is not just to do WiFi, but to make it transparent. They don’t have to do anything different to get the serial-to-IP connection, regardless of whether it’s wired or wireless.”

Until now, according to Young, WiFi has been problematic for some factory applications because all of the suppliers cater to laptops and personal digital assistants, which have graphic displays. This means the user can move around to find the best signal using the graphical signal strength display, he explains. “But in embedded applications, it has to work wherever you put it,” Young points out. “The story is that wireless local area networks have arrived for embedded devices, yet the installation and setup is still easy and use is transparent.”

Manufacturing professionals are faced with the task of getting more productivity out of legacy automation systems. Serial-to-IP devices promise much help in that effort. As Young states, “We see our service as enhancing the productivity of the device.”

Gary Mintchell,

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