Switches and sensors can be used to check that the parts, doors and guards are properly locked before the equipment is operational. These locks are crucial to ensure the accuracy of the production, the smooth and safe operation of the equipment. But all wired devices – whether limit switches or proximity sensors are not only limited in their area of ​​use, but also prone to wear and tear, requiring constant maintenance.
At present, proximity sensors are widely used in the factory floor simply because it is cheaper than conventional electromechanical switches. However, many manufacturers have found that proximity sensors need to be passively maintained from time to time, resulting in disruption to the production process.
Taking multi-axis machining as an example (such as engine castings), the fixture constantly rotates the part to be machined into position so that the wire approaching the sensor continues to move and undergo stress, causing the cable to gradually wear and eventually break. Once the cable breaks, the equipment and workers go idle due to the cable change (usually 15 to 20 minutes per change). If you replace the cable every 3 months (as some manufacturers do), the cumulative loss of productivity will be staggering. If you can predict when maintenance is required, preventative maintenance measures prevent downtime for maintenance.
Similarly, the coolant from the processing area of ​​the metal scraps come in continuous contact with the wire, the constant wear of the cable jacket, resulting in short circuit or continuity problems. Cable must be replaced at this time, resulting in loss of productivity.
In addition, one of the biggest problems that manufacturers face in terms of sensors and equipment is the number of connection points. Each connection point is a potential source of failure. If these connection points are eliminated, manufacturers can reduce the number of interruptions and times of their production processes.
Use the wireless limit switch can easily solve all the above problems. The widespread use of factory floor proved that wireless technology (especially 802.15.4.2.4Ghz) is a reliable solution. The benefits of integrating wireless technology into the switch are as follows: The switch does not consume power, but functions as a control – which extends battery life to two years or more under normal operating conditions. Built-in diagnostics in the RF circuit provide a low-battery indication to replace batteries that do not work well before a workflow is interrupted. This is important because sensors and RF circuits consume a lot of power and require periodic battery replacement.
The wireless switch can be easily retrofitted to applications that use standard wired or proximity sensors. Of course, no matter which type of wireless device is used, an RF (radio frequency) signal needs to be sent and must be converted to a standard input signal (PNP, NPN or relay) available to the control system. This is done through the wireless receiver installed in the device’s control panel. The receiver’s output is wired directly to the controller’s input card in a conventional wired manner. The controller can not distinguish whether the standard input comes from a wireless device or a wired device. The only difference is that now additional diagnostic input is added to monitor battery life and signal strength.
By reducing switch installation costs and providing greater application flexibility, wireless technology has revolutionized the field of factory automation. By eliminating the need for cables, manufacturers can dramatically reduce maintenance costs without downtime caused by connector and cable integrity and dramatically increase productivity. With the continuous release of new solutions and the increasing use of wireless technologies, using wireless devices to solve application problems will surely lead the new trend of factory automation technology.

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