JLS Designs Advanced Wireless Interfacing Units

这个项目的概念是应Draeger向我们表达的需求而发展的。对使用有毒或窒息气体的大气进行全面监测需要一些连接到中央控制和警报单元的传感器。通常，传感器通过支持4 mA到20 mA模拟信号的2线接口连接到控制单元；控制单元将测量的电流解析为气体水平，并相应地启动任何报警程序。开发和销售气体传感器的公司面临的关键问题是安装问题。控制单元通常必须位于办公室或走廊中，与传感器保持一定距离(S)，因此必须安装广泛且侵入性强的电缆。这对最终用户来说是一笔巨大的成本，而且在安装过程中也会造成相当大的干扰。构成该项目基础的解决方案是一套插接式数字无线接口。将实现一种设备，能够测量来自气体传感器的输出电流信号，并通过无线网状网络以数字方式传输该信息。将设计和制造一个类似的设备，从无线接口收集数据，并在控制单元再现测量的电流。这样，控制单元和传感器不需要改变来适应无线技术带来的好处，即部署的简单性和灵活性。这一新颖的解决方案特别有利，原因有三。首先，气体传感系统的最终用户在安装该系统时经历的成本和中断要少得多。第二个优点是无线接口对它们的应用是不可知的，因此它们可以在各种不同的应用中同样成功地使用。也就是说，无线接口本身不执行警报或控制；它们只是捕获并镜像控制单元中传感器的输出。这一过程可以很容易地被采用，例如，使用温度/湿度传感器的环境监测，或使用水流计和电力/煤气表的企业公用事业监测。第三个关键优势是，由于无线网状网络的原理，可以在应用程序中构建额外的监测设备，例如，可以独立地进行各种气体水平的数据记录，而不需要参考或中断控制和报警单元。该项目的重点是概念电子设备和固件的开发，这些设备将使无线电流测量和复制成为可能。该系统的每个核心组件(即电流感应、电流源和无线接口)已经以芯片组的形式在商业上提供，这样可以将项目风险降至最低，因为各个部件都经过了验证。该项目的挑战和新颖性在于将这些组件整合到一个可靠的、具有成本效益的一揽子计划中。

The concept of this project developed in response to a need expressed to us by Draeger.Adequate monitoring of atmosphere where toxic or asphyxiating gasses are used requires anumber of sensors linked to a central control and alarms unit. Frequently, the sensors arelinked to the control unit by a 2-wire interface supporting a 4mA to 20mA analogue signal;the control unit resolves the measured currents into gas levels and initiates any alarmprocedures accordingly.A key issue faced by companies developing and selling gas sensors is one of installation. Thecontrol unit must often be located in an office or corridor some distance from the sensor(s), sothat extensive and intrusive cabling has to be installed. This represents a significant cost to theend-user, as well as being a considerable disruption during installation.The solution, which forms the basis for this project, is a set of bolt-on digital wirelessinterfaces. A device will be realised capable of measuring the output current signal from a gassensor, and transmitting this information digitally through a wireless mesh network. A similardevice will be designed and built to collect the data from the wireless interfaces, andreproduce the measured currents at the control unit. In this way, the control unit and sensorsneed not be altered to accommodate the benefits that wireless technology brings; namely easeand flexibility of deployment.This novel solution is particularly advantageous for three reasons. The first is that the end-userof the gas sensing system experiences significantly less cost and disruption when the system isinstalled. The second advantage is that the wireless interfaces are agnostic as to theirapplication, so that they can be employed with equal success in a variety of differentapplications. That is, the wireless interfaces perform no alarm or control of their own; theysimply capture and then mirror the output of a sensor at the control unit. This process couldeasily be adopted, for example, with environmental monitoring using temperature/humiditysensors, or corporate utility monitoring using water flow meters and electricity/gas meters.The third key advantage is that, because of the principles of wireless mesh networks, it will bepossible to build additional monitoring devices into an application so that, for example, datalogging of the various gas levels can take place independently and without reference orinterruption to the control and alarms unit.The focus of this project is the development of concept electronics and firmware which willenable the wireless current measurement and replication. Each core component of the system(i.e. current sensing, current sourcing and wireless interface) is already commerciallyavailable in the form of chipsets which minimises project risk since individual parts areproven. The challenge and novelty for the project is the bringing together of these componentsinto a reliable, cost-effective package.