
WESTLOCK CONTROLS CORPORATION
280N MIDLAND AVENUE Ste.258, SADDLE BROOK, NJ 07663 TEL: 201-794-7650 FAX: 201-794-0913
www.westlockcontrols.com
2/3/12 TECH-457/D.W.O. 19909 Page 7 of 16
1.3 Description
This technical document provides information about the specific enclosure of a
wireless product. All other information regarding the complete wireless system
can be found on our website www.westlockcontrols.com or through our technical
sales department.
The Westlock Wireless Valve Monitoring System provides real-time information about
the status of valves installed in process plants. The data is fed directly into the
customer’s control system thereby reducing failure while increasing safety and yield.
The Wireless System is based on the ZigBee Pro standard protocol and serves as an
add-on layer, over traditional process management systems, providing enhanced
monitoring capabilities, with considerably reduced complexity. The wireless system
includes support for a wide range of standard interfaces, physical and logical, that are
common in the industry. This makes the wireless system, from the perspective of
connectivity, almost transparent for system designers and integrators, since they can
easily integrate into any of the most widely-used system architectures in the process
industry.
1.4 Principles of Operation
A Westlock Wireless Device (WD) is bracket-mounted to any type of valve or actuator.
Using the standard wireless 802.15.4/ZigBee Pro, 2.4 GHz protocol, the device
wirelessly transmits and receives messages relevant to the position status of the valve
in real time.
The WD is powered by 4 half AA Lithium batteries. In nominal operation
, the battery life
of the WDis above 10 years. A battery pack can be replaced in the field.
The WD includes a shaft that is fastened to the valve’s stem through a special cylinder.
It transfers the angle position of the stem to the WD. An internal WDsensor measures
the circular position of the WD shaft thus providing information about the angular
position of the stem in degrees relative to the valve.
The WD reports the valve position (angle) immediately when motion > 1.5 deg of the
valve lever is sensed and at configurable, predefined intervals. The WD temperature,
WD battery status, and other WD housekeeping information are broadcast with every
WD message. Each WDmessage is transmitted with a real time stamp. In between
transmissions the WD is in dormant status to save battery power.
The WD also consists of a Low Frequency (LF) receiver for receiving setting commands
from the Operator Device and to commission, decommission, calibrate, and setup the
unit and to perform diagnostic procedures.
Nominal operation is defined as 4 valve movements plus 4 keep alive messages per hour.