Diesel Progress North American

SENSORS & CONTROLS

Honeywell’s Limitless WLS heavy-duty wireless limit switch is designed for wireless position sensing or presence/absence detection in construction and transportation applications. The switch uses a global, license-free RF wireless protocol and has up to a 1000 ft. line-of-sight communication range.

New Switch,
Sensor From
Honeywell

Honeywell has developed two new products targeting vehi- cle and equipment applications. The Limitless WLS heavy-duty wireless limit switch is designed to offer the same mechanical life, temperature rating and sealing as the company’s standard Micro Switch limit switches, but with wireless capability.

The Superior Measurement, Accurate, Reliable, Thinking (SMART) 8.86 in. linear position sensor is a noncontacting sensing product designed for absolute position sensing in applications such as passenger bus leveling systems, truck-mounted crane outriggers, heavy equipment attachment identification, hydraulic cylinders and marine applications.

The Limitless switch, which uses a global, license-free RF wireless 802.15.4 WPAN protocol, can be configured to allow as many as 16 devices to communicate with a single receiver module, Honeywell said. The 802.15.4 open protocol RF board implements the wireless functionality with a panel-mount receiver or an industrial DIN-rail module receiving the wireless signal. The signal is then converted into an output, which can be in the form of LEDs, buzzers or electrical signals. The switch can also provide CAN, ProfiBus and standard Ethernet communications, according to Honeywell.

The wireless capability of the switch
allows users to reconfigure and net-
work multiple switches, making it easier
to add, subtract and relocate Limitless
switches, the company said. The ab-
sence of wires also means that there
is no wiring to install, no worn or torn
wires to mend and no cords to replace.

225 mm Analog

225 mm Digital

resist corrosion. An EN 50041 metal enclosure allows the switch to function in rugged environments and conforms to IP67 and NEMA 1, 3, 4, 6, 6P, 12 and 13 standards, Honeywell said.

Battery life for the Limitless switch can be as long as three years, depending on the application. The switch is targeted toward construction, transportation and agricultural equipment, as well as crane booms and lifts.

The SMART position sensor 8.86 in. linear configuration joins Honeywell’s 2.95 in. version that was introduced in December of 2009. They include a self-diagnostics feature and data gathering capability for closed-loop feedback control, Honeywell said. The sensor uses a patented combination of an application-specific integrated circuit (ASIC) and an array of magnetore-sistive (MR) sensors to determine the position of a magnet attached to a moving object, allowing the sensor to determine or control that object’s position, the company said.

The MR array measures the output of the MR sensors mounted along the magnet’s direction of travel. The output and the MR sensor sequence determine the nearest pair of MR sensors to the center of the magnet location. The output of these two MR sensors is then used to determine the position of the magnet within an operating range of zero to 8. 9 in.

The noncontact design of the sensor reduces wear, improves durability and minimizes downtime, said Honeywell. It has an air gap of up to 0.12 in. (±0.09) in. between the sensor and magnet and a variety of output options, such as analog, standard and other RS232-type baud rates.

The sensor, which conforms to IP67 and has IP69K sealing, measures values down to 0.0055 in. for analog and 0.000137 in. for digital. dp

Honeywell’s SMART 8.86 in. linear configuration sensor detects the position of a magnet relative to a sensor from zero to 8. 9 in. and measures values down to 0.0055 in. (analog) and 0.000137 in. (digital).