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 CELLULARIntelligent 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.ProSoft Technology661/716-5100
SMART BRIDGEMatchPort 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.Lantronix800/ 526-8766
WIRELESSCOEXISTENCE
InduraNetp features coexistence frequency management (CFM), so the system can coexist with other wireless systems in the 2.4 GHz ISM band and give immunity to interference from other wireless services. InduraNETp can be added to a new or existing I/O block without changing hardware. A maximum of 64 operational and safety input/output modules, each with two or four I/O, can be installed in any order alongside a single PSSuniversal head module.Pilz Automation Safety734/354-0272
BLUETOOTH SLAVESThe 750-644 Bluetooth RF-Transceiver module provides bidirectional, wireless communication between I/O nodes. Within 10 msec, the 750-644 exchanges data up to 1, 000 m (line-of-sight) or 100 m (within buildings). One 750-644 master can communicate with up to seven slaves on a personal area network (PAN), also known as a piconet, via Bluetooth 2.0+EDR radio technology. Slave-to-slave data transmission is possible indirectly through the master. Configuration is accomplished with Wago-I/O-Check 3 software.Wago800/din-rail
WIRELESS MODEMWireless Ethernet modems feature multiple layers of error-detection and correction, military-grade AES security encryption of wireless data, firewall protection and message filtering at MAC address level. Two serial interfaces, RS-232 and RS-485, as well as simultaneous serial and Ethernet connectivity and serial-Modbus-to-Modbus-TCP conversion, are offered. Discrete channel for status I/O, for failure status or external status transfer, along with remote configuration and diagnostics via the wireless link, are featured.Weidmüller800/849-9343
BUSABLE RADIOA busable 900 MHz radio, RAD-ISM-900-EN-BUS, allows direct connection of I/O modules. The radio includes a multiple master function to create redundancy and wireless failover connections if a master or host radio is not accessible. The radio allows the user to collect I/O without a remotely located PLC or I/O data concentrator. The bused I/O is made accessible to the network using the Modbus protocol and can be integrated into new or existing PLC, SCADA or DCS systems.Phoenix Contact800/322-3225
LOW LATENCYThe Gen II Zlinx wireless I/O product line features peer-to-peer mirrored I/O mapping, low-latency response rates of 8 msec/digital, field calibration, user-defined fail-safe output states and Modbus compatibility in a snap-together, expandable modular design. A remote I/O connection can be set up to any serial or Modbus system without running wire.B&B Electronics800/346-3119
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