一個(gè)工業(yè)物聯(lián)網(wǎng)的架構(gòu)（IIoT）應(yīng)用程序使用了大量的網(wǎng)絡(luò)傳感器和執(zhí)行器來監(jiān)視和控制工業(yè)過程。在工業(yè)互聯(lián)網(wǎng)參考架構(gòu)中，這種智能連接元素的集合被稱為邊緣層，一個(gè)典型的邊緣層節(jié)點(diǎn)位于或接近它所服務(wù)的機(jī)器。

　　邊緣層節(jié)點(diǎn)的設(shè)計(jì)對(duì)設(shè)計(jì)者提出了一些挑戰(zhàn)。隨著傳感器和執(zhí)行器，每個(gè)節(jié)點(diǎn)還包括一個(gè)微控制器，電源電路，并與網(wǎng)絡(luò)中的其他節(jié)點(diǎn)的串行通信鏈路接口。由于有數(shù)百或數(shù)千個(gè)節(jié)點(diǎn)，重要的是要保持成本和功耗最低。對(duì)于EMC產(chǎn)業(yè)環(huán)境是無情的，所以強(qiáng)大的防電磁威脅也是優(yōu)先。

　　IO-Link overview

　　IO-Link （IEC 61131-9） is a point-to-point serial communication protocol optimized for intelligent Edge Tier nodes that contain sensors， actuators， and low-power microcontrollers. In its basic form it is a three-wire connection that can switch both analog and digital signals （8， 12 and 16 bits）。 It has wide industry support due to its simplicity， intelligence， efficiency， configurability and ability to provide more information and control.

　　For example， it uses standard connectors and cables， eliminating custom connections. Using IO-Link， developers can identify devices and perform automated re-parameterization on the fly. Its Service Protocol Data Units （SPDUs） give access to detailed sensor and actuator status， from device type and ID numbers， to full diagnostics.

　　In a typical industrial installation， multiple IO-Link Masters operate actuators and collect data from sensors; they can also dynamically reconfigure sensors and actuators， known as “devices” in IO-Link terminology （Figure 1）.