Wireless technology is ideal for remote measurements, explains Robert C. Jackson, senior industrial and embedded product marketing manager at National Instruments (www.ni.com). "The one area where wireless sensor networks with embedded logic might first evolve for control is embedded distributed control. In these systems, the control, for example, a PID algorithm, would execute on an embedded processor instead of over the wireless network," he says.
Wireless control is extremely promising, but its application in industry is a bit more complicated, says Eric Hollister, product sales engineer, Pilz Automation Safety (www.pilz.com). "Industry is loaded with difficult and complex moving applications where wireless I/O and control have huge potential," he says. "However, wireless technology has not yet reached a point where it is stable or reliable enough to be used for industrial control," he says.
WirelessHART, the wireless extension of the HART protocol, could go beyond just measurement and monitoring functions to handle control functions, but this would need to be limited to non-critical, non-safety applications, says Robert Schosker, product manager at Pepperl+Fuchs (www.pepperl-fuchs.com). With wired communication there is 100% certainty that no information is lost between the controller and the field instrument, unless there is a failure in the wired lines, he says.
Intelligent cellular solutions combine industrial cellular technology, industrial protocol templates and ALEOS persistent connection management. The devices support industrial operating temperatures and Class I, Div. 2, hazardous location certification. The modules are suited for industrial automation applications. Versions are available for both serial and Ethernet devices for CDMA- and GSM-based cellular networks.
Smart Wireless field starter kit contains an out-of-the-box secure WirelessHART self-organizing network and includes any combination of five or more wireless pressure, temperature, DP level, DP flow, vibration or pH transmitters and discrete switches, a Smart Wireless Gateway, AMS Suite predictive maintenance software, wireless Snap-On for AMS Suite and Smart Start network health assessment and verification of device functionality and output to the user's Modbus, OPC, Ethernet or other communications system.
Emerson Process Management
|GATE TO THE HART
WirelessHART Gateway acts as the interface between the wired structure and wireless network. The WirelessHART Gateway contains the network management and uses it to organize and control the wireless network and connect this to a control or SCADA system, via fieldbus. The signals of the field devices are received and passed on via the appropriate bus protocol in the fieldbus. The WirelessHART Gateway can be installed in Zone 1 areas and can serve up to 250 WirelessHART field devices.
MatchPort b/g Pro embedded wireless networking module includes Ethernet-to-wireless bridging and SmartRoam technology, enabling MatchPort to switch between wireless access points and bridge wired and wireline networks. SmartRoam tracks the signal strength of nearby access points to prevent disruption in the wireless connection by transitioning to the access point with the strongest signal. The module is designed to transparently bridge existing Ethernet-ready devices to a wireless network.
The AWK-5222 has two independent RF modules for establishing independent wireless connections for rapid failover. The two independent RF modules are designed to give more topology choices to fit different wireless applications. In addition, it has a wireless redundancy mode to increase reliability, and its wireless bridge mode optimizes wireless distribution system. The AWK-5222's AP Client mode can be used to provide Internet access in areas where cabling would be too expensive or impractical to install. The AWK-5222 is also compliant with IEEE 802.3af, power over Ethernet (PoE).