Day: December 18, 2023 (page 105)

What is DB9 interface 2020-08-14 10:57:29 Zongheng Intelligent Control 1 DB9 interface introduction (1) The DB9 interface is a standardized interface commonly used in the early days of serial communication. (2) Serial communication was the main means for computers to…

What is simplex and full-duplex communication? 2020-08-14 10:30:48 Zongheng Intelligent Control 3 What is simplex and full-duplex communication? Simplex means one direction, and duplex means both parties send and receive at the same time. They can only send and receive…

The difference between serial port and parallel port 2020-08-13 14:12: 14Zongheng Intelligent Control 6 serial port The serial port is also called a serial port. Compared with the transmission speed of the parallel port, the transmission speed of the serial…

What is GPRS? The full name of GPRS DTU is GPRS data transmission unit. Currently, there is no specific name in China, and there is no clear agreement. Some people also call it data transmission terminal, data collection terminal, etc.…

What is a serial port communication protocol? There are several common ones. 2020-08-11 17:55:30 Zongheng Intelligent Control 5 What is a serial communication protocol? In layman’s terms: it is the protocol transmission method used in serial communication. The explanation in…

What is serial port parallel, serial port connection 2020-08-10 18:19: 13Zongheng Intelligent Control 4 Parallel and serial interfaces (1) Serial and parallel mainly consider the number of communication lines, which is the amount of information that the sender and receiver…

The development history of communications 2020-08-06 18:10:10Zongheng Intelligent Control 3 The development history of communications (1) The earliest communication: beacon tower, beacon; letter: electronic communication (telegraph, telephone, network signal) (2) The two most important aspects of communication are information representation…

Detailed explanation of Modbus RTU protocol 2020-08-05 17:31: 44Zongheng Intelligent Control 5 MODBUS_RTU communication protocol MODBUS_RTU communication protocol (this agreement adopts master-slave question and answer method) PDM series meters/transmitters: PDM series meters/transmitters adopt a brand-new design, which revolutionizes the concept…

What are link addresses and running addresses Link address and running address: may be the same or different. For position-related code, the running address during final execution and the link address given during compilation and linking must be the same,…

what is cache Cache is a kind of memory, called cache. In terms of capacity: CPU《Register》Cache《DDR In terms of speed: CPU 》Register 》cache 》DDR The cache exists because the speed difference between registers and DDR is too large. The speed…

“C Runtime” requires certain conditions, which are provided by assembly. The c language mainly requires a stack when running The relationship between C language and stack: Local variables in C language are all implemented using the stack. If our assembly…

What is a watchdog Watchdog (watch dog timer watchdog timer). What is a watchdog ? Let’s imagine this scenario: There is a dog at the door of your house. This dog will be hungry at regular intervals (for example, every…