How does the PLC exchange data with the operating software on the computer?

The equipment that can exchange data with the PLC needs to have the following characteristics: it has its own data processing and data exchange mechanism and address; It supports 485, Ethernet and different brands of PLC-specific communication protocols. If the above two conditions are met, you can communicate with the PLC.

As shown in the figure, 1 in the device window, 2 add a serial port parent device and Mitsubishi's driver file, and set the serial port parameters, communication parameters, 3 add channels, 4 set the added channels, 5 link the variables set in the configuration. Finish.

I find this stuff difficult. I've been working on this thing for about 1 year. gnawed c, c, and finally gave up.

The main thing is that it is too troublesome to collect various PLC function libraries. Now you can directly use other people's configuration software, modify and modify, and you can almost achieve that effect. It's just not that freewheeling.

Of course. If you are going to develop a similar software thoroughly. It is difficult to estimate the ability of one person.

Outsourcing it. It's easy.

This can be done, you can PLC directly to PC data, or PLC to HMI to PC. This only needs to use the serial port or network port to communicate. If you want to install the configuration software on the PC easily, but the PC configuration software requires an electronic dog, and the electronic dog has a cost.

If you want to save money, you can use your own software such as vb, vs, c++, etc., but this is very troublesome.

Through the way of communication, the data on the computer is transmitted to the PLC, and the common communication modes are RS232, 485, 422, modbus, profibus, etc., but professional software is generally required.

It can be communicated with third-party software using configuration software, through ODBC or OPC, etc. The configuration software is then used to write it into the PLC.

Hehe, make one up yourself, according to the communication protocol of the PLC.

This belongs to the communication and application of PLC and host computer, which is the so-called data acquisition and monitoring SCADA. Different brands or models of PLCs use different software, for example, AB's 5000 series requires RSLINX to be installed in the computer

class, the OPC function in RSLINX, can be configured to connect the computer to the communication module of the PLC, and all the tags can be seen through RSLINX! All that's left is how the computer application you write yourself to exchange data with rslinx! The same goes for other PLCs!

To add, between the computer and the PLC, it is generally possible to connect with Ethernet, and the PLC side needs to install the ENBT module of the Ethernet, and the specific configuration is in RS

studio. The general network card on the computer side is sufficient, and the IP address of the Ethernet network is configured. Then RS on the computer side

Linx uses the Ethernet configuration, and then you can find the electronic data in the OPC DDE menu, and then pour it into the tags in the configured PLC module and you will see all the data formed electron**, and then you can use it, in specific, I can only recommend looking up RS

LINX's OPC reference manual is available at Rockwell

Automation is available on the official website, and there is a Chinese version, carefully refer to it, just configuration, no programming required!

I don't know the specific situation of the water treatment machine, whether it is reverse osmosis or something else, if you need to start the pump, then do you need to adjust the speed, or just the AC contactor. In addition, does the water treatment machine need pressure control, flow control, valve breaking and so on! This set is also a PLC project!

However, what you are asking about is the data exchange between the water treatment machine and the computer, which is generally understood to be the data exchange between the PLC and the computer in the water treatment machine!

If it is not a PLC, but other systems, such as DCS, MCU system, this is different from PLC, and needs to be considered separately!

To write the driver first, read the data, and then write the data to the database regularly, quite troublesome, the driver is enough for you to write, generally buy ready-made configuration programs, such as configuration king, wincc, etc.

This is achieved by the wincc configuration software.

WinCC is the SQL database in the background.

1) Establish the connection between S7-300 and WinCC through the host computer software Step 7;

2) Access to SQL database via WinCC.

If you want to communicate with a computer, you need to do a communication program (with VB or others) from PC to Siemens PLC. For details, please take a look at the relevant information. If you don't want to be so troublesome, you can establish a connection with the database through configuration software (such as MCGS, Configurator, etc.), and then exchange data with Siemens PLC.

Here's a relatively quick and easy solution:

There are gateways that support MySQL databases, and most PLC protocols are supported;

Project examples.

1. There must be a communication interface;

2. There must be a communication protocol.

If the above two conditions are met, the data exchange between the VC application and the PLC can be realized.

Need to know the communication protocol of the PLC.