#ifndef _CRC_H_ #define _CRC_H static const unsigned char aucCRCHi[] = { 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, … Read more
In the field of industrial automation, the Modbus protocol has become the core standard for communication between devices due to its simplicity and wide compatibility. The Modbus function codes serve as the “instruction set” of the protocol, defining the types of commands between master and slave devices and determining the specific operations performed by the … Read more
-Begin-Hello everyone! I am Engineer Fu. Whether learning about host computers or PLCs, one topic seems unavoidable—communication. PLC communication focuses more on application; it only requires calling the corresponding function blocks and filling in the correct parameters, without needing to understand the underlying implementation principles. Host computer communication emphasizes the underlying principles, requiring knowledge of … Read more
1. Introduction Modbus, as a widely used general communication protocol, is extensively applied in frequency converters, smart instruments, and various intelligent devices. Previous articles have shared application cases based on the development of custom Modbus communication block instructions, specifically including the communication program implementation between S7-200SMART and Siemens V20 frequency converter, as well as Omron … Read more
Overview:The implementation method involves connecting field thermocouples to the temperature acquisition module, which connects via RS-485 to a serial server. The serial server converts the RS-485 signal to Modbus TCP protocol, allowing the DCS to collect data from the serial server. Main Tasks: Configuration of the multi-point temperature acquisition module; configuration of the serial server; … Read more
【Introduction】Starting from version V15 of TIA Portal, the Modbus (RTU) instruction set has been updated to version V4.0 and above. The S7-1200 firmware must be at least version V4.2. This article mainly discusses the new features of Modbus RTU version 4 and above. S7-1200 Motion Control Example Download S7-1500 Analog Module Wiring Diagram PLC Manual … Read more
Modbus TCP to HART – ADFWEB Gateway Converter– Guangzhou Xinyu IoT Author:www.adfweb.com.cn Zou Wuyi Mobile185-020-77899 Email: [email protected] 1、Features: HD67909-A1 is a Modbus TCP slave /HART master converter. It has the following features: Triple isolation between Ethernet and power, Ethernet and HART, and HART and power; Bidirectional information transmission between the Ethernet bus and HART bus; … Read more
To understand the communication processes of Modbus TCP and Modbus RTU, we need to consider their frame structures, transmission mechanisms, and master-slave interaction logic. The former relies on the TCP/IP protocol stack for “reliable transmission,” while the latter transmits “binary data” directly over serial ports. The core differences lie in the “data encapsulation” and “link … Read more
RS485 is Not a Language, But a ‘Highway’ Let’s use a vivid analogy to understand: RS485: It is like building atwo-way, two-lane highway. It specifies how wide this road is (transmission distance, up to 1200 meters), how many vehicles can run simultaneously (load capacity, up to 128 devices), and the basic rules for vehicle operation … Read more
Hello, good evening everyone~ Today we have another technical article about Siemens communication! Siemens Modbus RTU Communication: S7-200 Smart Modbus RTU Master Station Communication (√) S7-200 Smart Modbus RTU Slave Station Communication (√) RS485/232 Communication Ports and DP Connector Connection Methods (√) S7-1200 Modbus (RTU) Instruction V3 Basic Functions S7-1200 Modbus (RTU) Instruction V4 New … Read more