Industrial Networking

Networking infrastructure continues to operate as a collection of old and new; digital and analog; connected and isolated; throughout U.S. plants. So say the findings from a new Control Engineering and Reed Corporate Research study on CE subscribers’ use of and plans for industrial networks and communications. Link to research study.

By Peter Welander, Control Engineering April 1, 2007
SCADA and diagnostic systems are used in all industries, but discrete and process industries begin to separate as specific control functions emerge.

Networking infrastructure continues to operate as a collection of old and new; digital and analog; connected and isolated; throughout U.S. plants. So say the findings from a new Control Engineering and Reed Corporate Research study on CE subscribers’ use of and plans for industrial networks and communications .

The results were taken from 213 respondents involved in specifying, recommending and/or buying industrial network products. Given the nature of the responses, networking takes many forms and exists in a wide variety of ways. Communication can be as simple as a sensor and display tied via 4-20 mA, or an Ethernet platform spanning several levels from enterprise to plant floor.

Most companies (61%) use network driven SCADA (supervisory control and data acquisition) systems (See Most frequently named uses graph.) and most (51%) extend that to include diagnostics, testing, and maintenance. Additional answers suggest divisions between discrete and process manufacturing needs.

This list shows the remarkable variety of networking protocols in use, each with its own purpose and applications.

The nature of frequently used protocols reflects typical applications. (See Most frequently named protocols graph.) Analog techniques, such as 4-20 mA and 0-10 V, are still common enough to make the top 10, but have few uses outside of simple instrument-to-I/O connection. Ethernet platforms, Ethernet TCP/IP and EtherNet/IP, appear in 84% and 66% of plants, respectively, implying wider networking between higher level devices. Older serial protocols, RS-232 and RS-485 persist as platforms for smaller simple or multi-node networks.

Commercial Ethernet and fieldbus platform families are strong, led by ODVA group with EtherNet/IP, DeviceNet, and ControlNet all showing in the top 10. Modbus and Modbus/TCP placed second with the Profibus and Foundation fieldbus protocol groups named third and fourth.

Technology use changes slowly, which makes trends hard to spot, but wireless, especially WiFi (IEEE 802.11b) shows the most movement, with 40% saying they use it currently, up from a statistical dead heat at 34% in 2006, and 35% in 2005. Other wireless technologies (including RFID) are positioned for growth, with the following the highest cited for new use in the next 12 months:

  • RFID, +17%;

  • ZigBee (IEEE 802.11g), +16%;

  • WiFi (IEEE 802.11b), + 14%; and,

  • Bluetooth (IEEE 802.15), +13%.

At the same time, the extensive amount of hardware that is not yet networked is also telling. While PLC’s, and Ethernet devices (hubs, switches, routers, etc.) are integral parts of larger networks, other types of devices can go either way. In fact, on average, slightly more than half of installed instrumentation and sensors are currently not networked, although if plans to connect them over the next 12 months pan out, the balance will shift pushing most process and discrete sensors, switches, and valves over the 50% mark.

Networking hardware and software figures high in plant budgets as they upgrade and maintain systems.

Networking requires both hardware and software to maintain and expand. Respondents report extensive plans to enlarge and upgrade their infrastructure. (See Purchase plans graph.) I/O devices and connectors top budget lists year after year, followed by cabling and controllers. The figure shown in the graph is an average of all respondents for their specific company in the given product class.

Networking hardware suppliers

The top four companies supplying networking hardware products named by respondents in this year’s survey are Rockwell Automation, Belden, Schneider Electric, and Phoenix Contact. Representative offerings from these companies are shown here.

  • Links to more than 50 other vendors with products related to industrial networking are located with the online version of this article under April 2007, .

  • Find other suppliers at .

  • Find system integrators with related expertise at .

  • Control Engineering Product Research reports are available free with registration at / .


Fast analog module for high-speed processing applications

New fast analog module from Rockwell Automation improves data transfer and overall performance of Allen-Bradley Control Logix programmable automation controller (PAC) family. Using an on-board data archive, the module eases integration into new or existing systems and increases system throughput by reducing overhead required in collecting high-speed data. Featuring four archiving inputs and two outputs, the fast analog module collects up to 20 samples of data at a time, which are stored in the module’s on-board buffers. By storing data until 20 samples are taken, the module lengthens time between I/O data transfers, which the company says relieves the controller of burdensome information and decreases process disruptions. The archiving feature allows for configuration selections, such as data type, tag generation, and connection between the controller and high-speed analog I/O module. All features and configuration options are available through Rockwell Software RSLogix 5000 programming software.

Rockwell Automation

New Ethernet cabling toughened for industry

Belden’s line of DataTuff industrial Ethernet cables has grown with the addition of three new enhanced 4-pair, category 5e twisted pair cables. All three use 24 AWG solid, bare copper conductors and halogen-free insulation. The 7935A is unshielded EtherNet/IP compliant, with rip cord, polyolefin insulation and .030 in. black, low smoke zero halogen jacket, rated NEC/CEC: CM FT1; 7936A is shielded EtherNet/IP compliant, with stranded TC drain wire, Beldfoil shield and same jacket as 7935A, rated NEC/CEC: CMR/CMG FT4; and 7937A is waterblocked for buried applications, with stranded TC drain wire, PE inner jacket, Beldfoil shield, and sunlight- and oil-resistant black PE jacket. Fully waterblocked per Telcordia, IEC, and ICEA specifications.

Belden says these cables compliment their line of DataTuff copper and TrayOptic optical industrial Ethernet cables, including a variety of Cat 5e and Cat 6 products.


Ethernet switches toughened for industry

Ethernet switches designed for office use don’t always last in industrial applications, so Schneider Electric offers its line of toughened Telemecanique ConneXium components designed for reliability in difficult conditions. The IP67-rated Ethernet switches are suitable for direct installation in machines on a plant floor, indoors or out, even where water spray and rain can hit; extended temperature unmanaged Ethernet switches can operate in environments from -40 to 70 °C (-40 to 158 °F); and, a Modbus to Ethernet gateway provides connection from shop floor Modbus serial line to larger Ethernet-based network. The company says this family of hubs, switches, bridges, and transceivers is designed with high resilience for specific industrial environments.

Schneider Electric

Fiber optic converter upgrades extend applications

Phoenix Contact introduced two new PSI-MOS Profibus fiber optic converters with conformal-coated printed circuit boards. The converters were designed primarily for use in shipbuilding and marine industries, where environments can lead to PCB corrosion. Conformal coating gives added protection from saltwater, as well as moisture, dust, and other corrosives common in hostile industrial environments. All company copper to fiber optic media converters are approved for use in UL Class 1, Division 2, hazardous locations, common in petroleum, chemical, pharmaceutical, and water/wastewater industries.

Phoenix Contact

Author Information
Peter Welander is process industries editor. Reach him at