前四篇文章讲述的是TCP/IP 模型中的网络接口层、网络层、传输层、应用层一，这里到了第四层应用层二。由于协议比较多，就分开篇来介绍。这篇讲Modbus 协议,后面再讲 MQTT协议、CoAP 协议、OPC 框架。都是物联网常用的应用层协议。 第四层：应用层协议之二-物 ...

“Not being overcomplicated is Modbus TCP/IP’s biggest draw, not only for PLCs, but especially for PC-based applications,” said Jason Haldeman, senior product specialist for I/O and networking at ...