PLC and inverter communication problems? Thank you for your advice

485 is just a hardware interface, a kind of circuit level problem, now PLC and inverter are 485, which means that they can be hardware compatible, that is, circuits can form a loop between them, and there is no problem with the hardware basis of communication. As long as you know the communication protocol of the inverter and the communication instruction format of the PLC, then you can use the PLC as the host and the inverter as the slave, and establish an agreed protocol between them, so you can communicate, so your idea is feasible, but you need to program. It's like if you want to have a relationship with an American, and you agree to meet in a restaurant, the restaurant is the hardware, you talk to the software, and you have to know English to be an agreement.

In practice, we use the Profilebus bus to connect the PLC and the inverter, because usually the PLC has more than one inverter, and the RS485 can only be connected to one.

It depends on what protocols they support, and things are different from different manufacturers.

Theoretically possible, the distance of communication and the reaction speed of the system need to be considered.

What inverter What PLC doesn't say anything What do people say.

Hello Yes There are many ways to control the inverter by PLC, the first one, pure hard wire control, you can use the opening point to control the start and stop of the inverter, after the inverter sets the multi-stage speed, you can also control the speed through the corresponding opening point. The second is to control the speed with the analog quantity, the third is to control the speed with the pulse, the start and stop with the open point, the fourth is the communication control, the multi-purpose control is the communication mode of modbus rtu, this 116 square 45 type can be 78887 to control the start and stop, control the speed, and can also read the various states of the inverter. Hope it helps.

Signal transmission between the inverter and the PLC often requires the use of digital communication protocols. Commonly used digital communication protocols include Modbus, Profibus, CanOpen, etc. Here's a basic example process:

1.First of all, it is necessary to establish a communication connection between the frequency converter and the PLC. 2.

Configure the communication parameters of the inverter and match them with the communication parameters of the PLC. 3.Write a program in the PLC to read or write the inverter parameter chiling chain, send control commands to the inverter, and other operations.

The inverter will perform the corresponding control tasks, and send the feedback signal back to the PLC to receive the feedback signal and process it according to the needs of the code, such as alarm, shutdown and other operations, and can also be used for the next control task. It is important to note that the exact signaling method and configuration may vary from device to device. Reliable signaling requires hardware and software support, as well as proper configuration and debugging.

The use of specific development tools and communication protocol documentation is often required to ensure proper signaling and data exchange.

The signal transmission between the inverter dust collector and the PLC can be completed by the following steps:1Determine the communication protocol between the imitation greenhouse PLC and the inverter, such as modbus, profibus, etc.

2.Write relevant instructions in the PLC program to read or write the parameters or status information of the inverter. 3.

The control interface of PLC and inverter is connected through the input and output module of PLC to realize data exchange and transmission of control commands. 4.Configure the parameters of the inverter so that its standby can respond to the signal sent by the PLC and perform the corresponding control operations.

5.Test and debug the communication system to ensure that the PLC can read and control the inverter correctly. It should be noted that there are some basic safety specifications and operating standards that need to be followed when carrying out signal transmission between the inverter and the PLC to ensure the stability and reliability of the system.

At the same time, the communication process needs to be monitored and recorded to facilitate future troubleshooting and maintenance.

How did the communication failure between the inverter motherboard and the PLC occur? How to fix it?

Fault phenomenon: 1) The inverter touch screen reports that the communication between the motherboard and the PLC is faulty, and the PPI cable receiving light RX light is off or does not flash. Each power indicator on the motherboard is off.

The high voltage is still applied to the module input, and the module output is blocked. 2) The inverter touch screen reports that the motherboard and PLC communication failure, and the PPI cable sending light TX light is off or does not flash. 3) The touch screen reports that the communication between the motherboard and the PLC is faulty, and the PPI cable power light knows that the POW is not on.

Cause of failure: 1) During the operation of the inverter, due to the failure of the power supply switching power supply PW1 of the main board or the DC power supply on the main board, the power supply of the whole motherboard is lost, and the IGBT switch signal stops. Therefore, the communication failure between the motherboard and the PLC is reported; module blocking output; At the same time, due to the power loss of the motherboard, the fault trip signal cannot be sent, and the high-voltage power has been added to the module.

2) The motherboard cannot receive the communication signal sent by the PLC, and there is a problem with the communication part of the PLC itself. 3) The PPI cable itself is faulty. Workaround:

1) Replace the damaged motherboard or switching power supply. 2), replace PLC3), replace PPI cable.