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 ...
寄存器数值是0x1234,先传输0x12,再传输0x34。 在Modbus寄存器中,对于一个由2字节组成的16数,在内存中存储这两个字节有两种方法:一种是将低序字节存储在起始地址为小端(Little-Endian)字节序;另一种方法是将高序字节存储在起始地称为大端(Big-Endian)字节序。
校验码:校验码通常是一组数字的最后一位,由前面的数字通过某种运算得出,用以检验该组数据的正确性。代码作为数据在向计算机或其它设备进行输入时,容易产生输入错误,为了减少这种输入错误,编码专家发明了各种校验检错方法,并依据这些方法设置了 ...
Modbus协议采用主从式通信,日常使用较多的是Modbus RTU和Modbus TCP/IP两种。 比较常用的Modbus通信调试软件有ModScan32和ModSim32。 ModScan32主要用来模拟主设备,它可以发送指令到从设备(使用Modbus协议的智能仪表等设备终端),从机响应之后,就可以在界面上返回相应 ...
Modbus TCP connections pose many benefits over RTU RS-485 alternatives. Image: PV Tech. In the last couple of years, the market has seen a few commercial and industrial (C&I) inverter models and ...
Open communication protocolsModbus TCP/IP is an open industrial protocol based on standard Ethernet. Modbus provides connectivity to programmable automation controllers (PACs), PLCs, and legacy ...
A MiMiC Simulation Driver allows I/O and process simulation for devices that support the Modbus TCP/IP protocol. The driver provides high-speed simulation for Modbus controllers; quick and easy set up ...
ProSoft Technology, Inc. has released the Modbus TCP/IP to IEC 61850 Gateway. The gateway provides an efficient method for integrating smart grid-compliant IEDs with the Schneider Electric Unity ...
The Modbus TCP/IP to IEC 61850 gateway provides a distributed solution for interfacing smart-grid-compliant IEC 61850 Intelligent Electronic Devices (IEDs) at the process and bay levels with Schneider ...