Networks busting out all over (Expanded online version)
It’s not quite spring yet, but industrial networks seem to be popping up on plant floors like those proverbial flowers after April showers.
Implementation of networking methods, fieldbus protocols, hardware, software, and related equipment appear to be increasing in more numerous and more diverse applications across almost all manufacturing industries. The long-awaited critical mass at which the majority of point-to-point, hardwired networks will shift to twisted-pair fieldbuses, Ethernet, Internet, and wireless may not have occurred yet, but it may be getting started. Whatever the long-term outcome, a lot more users seem to be renovating their networks with new technologies and methods.
In November 2004, Reed Research Group compiled and analyzed 132 qualified responses to a Web-based survey of Control Engineering subscribers involved in specifying, recommending, or buying industrial networking products. Among these, 86% do so for in-plant requirements, while 39% buy for OEM requirements.
For at least the third year, more than half (59%) of the qualified respondents to Control Engineering and Reed Research Group’s “Industrial Networking Product Research, March 2005,” report that their primary applications for networking are supervisory control and data acquisition (SCADA) systems. This was a slight increase from the 55% using networks for SCADA in 2003, but still down from the two thirds using networks for SCADA in prior years. This trend and other evidence in the study clearly show that the breadth and depth of industrial network implementation is increasing significantly.
While respondents using networks for diagnostics, testing, and maintenance (42%) or for continuous and batch processing (37%) remained almost the same as a year earlier, those using networks for motion control and robotic equipment (34%) or machine control and computer numerical control (CNC) equipment (30%) each increased by about six percentage points over 2003.
To help them implement these new and initially unfamiliar networking technologies, more users are seeking assistance from system integrators and other third-party consultants. For example, 55% of 2004’s respondents report using integrators, while only 49.8% used integrators in 2003 and 2002. Likewise, spending on integrators also increased to an annual average of $83,200 per respondent in 2004, which was up from an average of $72,066 in 2003.
As always, users tie numerous types of devices to industrial networks. However, also for the first time in several years, more users say they’re planning to connect to networks in the next 12 months than who report that they’re presently connected. [See “Past, present, and future use of products tied to networks” bar chart.]
In addition, network hardware (81%), network software (78%), and I/O products and systems (77%) took over in 2004 as the categories most linked to users’ networks from PLC hardware (75%), which had been the most-connected types of devices in the past two annual surveys. In fact, while many of the most used product types linked to networks gained three to six percentage points during 2003-04 and project similar gains for 2004-05, some less prominent product categories posted double-digit gains. For example, flow sensors and/or transmitters linked to networks increased from 53% to 60% in 2003-04, and are expected to jump to 70% in 2004-05. In addition, motion feedback device ties to networks shot up from 47% to 57% in 2003-04, and are expected to increase to 63% in the coming year. Also, process analyzers connected to networks skyrocketed from 34% to 46% in 2003-04, and are projected to reach 52% in the next 12 months. Only I/O products and systems linked to networks were expected to remain flat at 77% in the coming year, perhaps cooling off after increasing from 71% the year before.
Fieldbuses, Ethernet, wireless taking off
Paralleling the fact that more users in 2004 connected devices and applications to networks, respondents add they’re using more fieldbus protocols, Ethernet, and even wireless networking technologies. [See “Past, present, and future use of fieldbuses, network methods” bar chart.]
Meanwhile, use of the main hardwired networks is declining or remaining flat. For instance, use of probably the most pervasive legacy network, 4-20 mA, declined from 72% to 68% in 2003-04, and is projected to drop another four points to 64% in the next year. Ironically, the largest gain by a networking protocol was posted by the relatively low-level, easy-to-implement AS-Interface, which jumped from 6% to 17% in 2003-04, and is expected to reach 21% next year.
This gain was closely followed by FOUNDATION fieldbus H1, which increased from 17% to 23% in 2003-04, and is projected to jump 31% in the next 12 months. Similarly, Modbus TCP shot up from 24% to 34% in 2003-04, and expected to increase to 38% in the coming year.
Interestingly, though it remains the most-used network at 78%, Ethernet TCP/IP declined three percentage points from 81% in 2003, but is projected to rebound to 84% in the coming year.
Though surveyed for the first time, some new networking methods appear to be making significant strides into the networking arena. For example, 27% of respondents presently use Ethernet Powerlink, while 29% plan to in the next 12 months. Similarly, Firewire (IEEE 1394) is now used by 25% of those polled, while 35% plan to install it in the coming year. Also, the respondents add that 21% use Field Device Tool/Device Type Manager (FDT/DTM), but 29% plan to in the next year.
Also tracked for the first time, wireless networks demonstrated a significant presence and are projected to make impressive gains. For example, 35% of users have WiFi (IEEE 802.11b) installed now, while 42% plan to in 2005. Similarly, 22% now use Bluetooth (IEEE 802.15), while 33% plan to in the coming year. And, 15% now use Zigbee (IEEE 802.11g), while 21% plan to in the next 12 months. Meanwhile, radio frequency identification (RFID) is presently used by 26% of those surveyed, but 37% say they plan to use it in 2005.
“The move to open protocols, such as Ethernet’s TCP/IP, from proprietary networks has been going on for 10-12 years, but people are getting even more interested in them now, and especially in how to achieve secure communications between the process control and enterprise networks,” says Bret Popp, Honeywell Process Solutions’ network services manager. “So, we’re putting in a lot of firewalls and DMZs (demilitarized zones) between the process and enterprise levels. A DMZ is a third leg, basically a proxy area, into which process data can be moved. This allows information to be distributed to and used by the enterprise level, but prevents the enterprise level from being directly connected to the process. Authorized users can even log onto a DMZ, copy data, and work on the process network without affecting it.” Honeywell’s DMZ solution functions at level 3.5 on its four-layer Fault-Tolerant Ethernet (FTE) solution.
Industrial networking products
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ControlNet PCI cards provide compatibility
To provide compatibility with more industrial and personal computers, Rockwell Automation’s universal ControlNet PCI cards, 1784-PCIC and 1784 PCICS, can detect and quickly adapt to varying voltage amounts. This means users can apply them to virtually any computer using a PCI bus, which makes it possible for almost any plant-floor PC to use networking technologies. The cards’ voltage is based on the standard PCI bus, so users can link their applications to any ControlNet network. In addition, the company’s ControlNet PCI Bus Bridge card has a total of 128 connections, of which 127 can be scheduled. Once scheduled connections are established, the card guarantees sufficient data buffers required to reestablish these connections if they are broken. Both cards support redundant media operation.
Industrial Ethernet cable lines expanded
Belden CDT Electronics division’s expansion of its DataTuff data cables includes the addition of one two-pair and three four-pair Category 5e cables. The firm’s industrial Ethernet cables include DataTuff Cat 5e and Cat 6 twisted-pair copper cables and TrayOptic fiber-optic cables provide reliability even in the presence of electromagnetic interference (EMI) or radio frequency interference (RFI). They’re also constructed to withstand harsh industrial and environmental conditions, including oil, sunlight, wide temperature variations, abrasion, and crushing, and still prevent data transmission errors.
FOUNDATION fieldbus linking device links H1 to HSE
ABB reports that its LD 800HSE linking device lets users access field devices connected to FOUNDATION fieldbus from supervisory and control systems. LD 800HSE is a compact gateway between field devices on up to four H1 links and a high-speed Ethernet (HSE) subnet. Republish-ing data from an H1 link to the HSE subnet, as well as from one H1 link to another, enables cyclic communication between field devices on different H1 links and devices on the HSE subnet. It allows client/server access to function blocks on H1 devices via HSE. For each H1 link, it manages the live list of connected H1 devices and grants access to them. The device is qualified for redundant use, where the corresponding H1-ports of two linking devices are connected to one H1 link. Redundant linking devices are interconnected via a serial RS-232 null modem cable to exchange redundancy control information.
Two CPUs have built-in Profibus
To reduce installation costs, improve performance, and increase uptime, GE Fanuc Automation Americas Inc. says two new CPUs for its Series 90-30 PLCs have built-in Profibus master and slave controller capabilities, which allow the CPUs to send and receive I/O data from a Profibus-DP network. The CPU modules’ built-in capabilities minimize wiring back to the controller, decrease system complexity, and reportedly provide improved system performance over a standalone Profibus module. Series 90-30 modules reportedly are ideal for applications requiring high-speed data throughput to remote devices, such as remote I/O, motion, bar-code systems, motor starters, weighing and dosing systems, HMIs, and energy systems.
Fault-tolerant Ethernet improves availability
Honeywell reports that its patented Fault-Tolerant Ethernet (FTE) solution can link the benefits of Ethernet technology with the company’s expertise in designing robust networks. Available with Experion and other Honeywell systems, FTE is designed as an advanced networking solution using commercial-off-the-shelf (COTS) equipment and network hardware. FTE reportedly provides increased system availability, while reducing commissioning and maintenance costs. FTE also employs one network and doesn’t need a server or station to reestablish its network connection. As a result, FTE’s switchover time is typically 1 sec.
Switches cut cost of Ethernet networking
Four new Telemecanique industrial Ethernet switches from Schneider Electric provide increased functionality at lower cost have been introduced by Schneider Electric. ConneXium five-port, unmanaged, Ethernet switches are designed to connect single devices or complete network segments. They are an alternative for applications in which a copper-to-fiber conversion is needed with independent links on both segments. These switches support Ethernet 10-MB and fast Ethernet 100-MB, as well as switched Ethernet networks built to IEEE standard 802.3 or 802.3u using cooper and fiber-optic technology. TP copper ports support half/full duplex and 10/100 Mbps auto-negotiation, auto-polarity, and auto-crossing. The fiber-optic ports support full duplex. There is no limitation to the number of switches that can be cascaded in either bus or star topologies.
Control system delivers predictive intelligence via fieldbuses
Ovation expert control system from Emerson Process Management includes an integrated digital bus that uses F OUNDATION fieldbus, HART, DeviceNet, and Profibus DP to deliver predictive intelligence from intelligent field devices, including Rosemount transmitters and analyzers, Micro Motion Coriolis flowmeters, and Fisher digital valves. Ovation also incorporates embedded advanced control applications for users in the electricity generation industry, and its new features provide the predictive intelligence needed to improve plant performance. As a key part of PlantWeb digital plant architecture, Ovation’s integrated digital bus technologies deliver diagnostic information from the field to Ovation.
Emerson Process Management
Smart DeviceNet slave simplifies maintenance
Omron Electronics’ DRT2 smart DeviceNet slave can monitor I/O status and network communications status, and it allows users to remotely monitor and diagnose common problems, such as low network voltage, communications errors, and short circuits for connected devices. When combined with Omron’s Configuration Software, DRT2 lets users connect to and monitor the factory floor network over an Ethernet connection without control programming or interruption. DRT2 also monitors the number of operations and total operation time, which allows it to provide notification when maintenance is required. DRT2’s expansion capabilities allow one node to attach one expansion block of either inputs or outputs to the main block, which reduces the number of total nodes required for a system.
System I/O includes DeviceNet, Profibus gateways
Banner Engineering’s InterlinkBT division reports that its BL67 system I/O combines the flexibility of in-cabinet PLC I/O systems with modularity, ruggedness, and “connectorization.” BL67 consists of a gateway, base modules, and electronic modules. Its I/O modules aren’t dependent on the fieldbus protocol. The gateway coordinates I/O data exchange, and generates detailed diagnostic information for the control platform. Gateways are currently available for DeviceNet and Profibus-DP. BL67 system also offers group, connector, channel, and module diagnostic information. BL67’s small size allows up to 32 electronic modules, up to 256 digital or 64 analog I/O points, and is DIN rail or flange mountable.
Standard-function Ethernet switches at hub prices
Phoenix Contact reports that its standard-function (SF) unmanaged Ethernet switches cost 35-50% less than other devices, which means that multi-mode fiber/copper mixed switches are available at media converters prices. The firm adds that affordable, fully switched Ethernet systems with high immunity will make traditional industrial hubs obsolete. SF switches combine switched Ethernet connectivity for 8 or 16 (10/100 Mbps) ports with a reportedly unique range of one or two multi-mode, 100-Mbps glass fiber-optic port options. System startup time and ongoing maintenance costs are further reduced by unmanaged switch functions, such as redundant power supplies, alarm contact, auto negotiation, and cable auto-crossing.
Wireless gateways share data‘over the air’
ProSoft Technology’s ProLinx 6000 wireless gateways allow users to connect various field devices using different networks or protocols, and wirelessly share data among devices. This is accomplished by selecting the appropriate protocol/network, which provides a connection to the hardwire device. The process next converts the protocol and its data into a common radio packet, ProSoft Wireless Protocol (PWP), or standard industry protocols, such as EtherNet/IP or Modbus TCP/IP, and sends them to other wireless gateways in the system. The two conversion methods include using standard industry protocol or PWP.