The choice of domestic oyesplc communication proto

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Selection of domestic oyes PLC communication protocol

man machine interface is used for information exchange between operators and PLC. The small digital quantity control system using a single PLC generally uses indicator lights, alarms, buttons and operation switches as the man-machine interface. The digital input and display functions of PLC are poor. The digital input and display can be realized by using the digital i/o points, dial switches and led seven segment display of yes PLC. However, it takes up a lot of i/o points and may require user-made hardware

human machine interface (HMI) generally uses special equipment for dialogue and interaction between operators and control system. Next, we will introduce the selection of oyes communication:

when selecting the communication mode, we should consider the maximum number of nodes allowed in the communication network, the maximum communication distance and whether the communication interface needs photoelectric isolation. When selecting the communication rate, the possible maximum amount of information of the yes PLC module in the network unit time shall be considered, and a certain margin shall be reserved. The communication rate is related to the length of the communication line. When the communication distance increases, the maximum communication rate decreases

the communication between computer and PLC is common in the actual system. If users use VB and VC to write the communication program of computer, it is much simpler and more convenient to use MODBUS slave protocol than to use free port, and users do not need to write the communication program of PLC. The response frame is automatically generated by the PLC operating system

if the upper computer uses configuration software, neither the upper computer nor the PLC need to program gb/t 14800 ⑴ 993 test method for bursting strength of Geotextiles (equivalent to ASTM D 3787) gb/t 13763 ⑴ 992 test method for bursting strength of Geotextiles by trapezoidal method. If the communication is completed automatically, the system development time can be reduced, but the cost of purchasing configuration software is increased

The free port mode of

s can be used for communication between PLC and computer or other RS485 devices. This communication mode is the most flexible, and the user-defined communication protocol can be used. However, the programming workload of PLC is large and the requirements for programmers are high

it has a very wide speed regulation range and beam shifting. 3. Technical training: moving distance during equipment commissioning tags: domestic PLC yes PLC

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