The project does not come with PLC, how to convert the analog quantity in WinCC and give an alarm

Thank you for your reply, the method of the friend upstairs is undoubtedly very suitable for the range is a fixed variable, but I forgot to say here that the range of my variables needs to be set on the screen, that is to say, to make it a general type, the customer needs to modify the range on the screen according to the actual type of analog quantity. The purpose of this project is to be general-purpose, not a dedicated project, so the addresses of variables are required to be very flexible, and user permissions are required to change.

Use a script to calculate the final output value, and similarly, use a script to determine whether the output value exceeds the set value, that is, whether there is an alarm (alarm variable, bit type), so that the analog alarm becomes a bit alarm. It's easier to handle.

Thank you for your guidance, at present, this function has been implemented in the global script, ** shared as follows: inti; char*ctagname[8]=;char*chrange[8]=;char*clrange[8]=;char*ctagconverted[8]=;floatai[8],hirange[8],lorange[8],aiconverted[8];for(i=0;i<=7;i++)return0;

This project does not have a PLC, and communicates directly with the data collector through DDE, and then needs to convert the range of more than 100 analog quantities collected in WinCC, and trigger an alarm after comparing with the high and low limits. I haven't done this way, I don't have a clue, and there are more than 100 ways, please show me the way.

Operator analogue alarm notifications, such as the current temperature or pressure is too low, too high or at a dangerous level, can be configured with a single variable configuration. The actions taken by the operator in response to the alarm message can also be defined and described here. Step1 In the WinCC Project Manager, right-click on the "Alarm Logging" device and open it.

Very simple. Delay 1 second, assign the current value to an address, such as md100 and delay Dansen for 1 second, assign the current value to another address, such as md104 and calculate the difference between md104 and md100.

When the difference is greater than a certain value, jump to the alarm program.

If the difference is within the allowable range, jump to the first step of the mold matching mu and repeat the above procedure.

Be careful not to write an endless loop, that's going to be a problem.

Then set up a variable at the output point of the alarm program at wincc.

Use the "true" or "false" of this variable to trigger the WinCC sound alarm C action.

Note: The program section can be written in the Time Interrupt Tissue block.

Whether the communication between PLC and WinCC is normal can be detected from the following aspects:

2. Use WinCC's built-in channel diagnosis and communication detection plug-in.

How to use it is as follows:

Open WinCC and find Variable Management. Right-click the menu, insert the new driver, and find the file that starts with S7.

And then there are channels that connect 300,400. In there there are corresponding (you use dp, you make a connection there in dp) connections and variables.

When selecting the location of the variable, just write the address corresponding to the plc. This one is very intuitive.

All right. Just use it directly on the screen. It will automatically refresh according to the change of the value in the PLC.

Of course, if you change it from the picture, it will change in the PLC. As for what is the final variable? It's up to you.

If the program doesn't change that variable (such as MD100 in PLC), just use this address, then it can change the cool from the screen, which is commonly known as setting control parameters.

For the new connection, you need to set the address of the PLC or something. No, you can do it again**. Otherwise, how can a lot of PLCs and an industrial computer be connected. I don't know what kind of net you use, ether, dp, mpi can be.

If you connect 200, you need to insert the OPC channel. Then you also need the OPC server software. There are two to choose from:

PC Access, or SIMATIC NET. The first one is much simpler, and the second one is very difficult.

When creating a new one, select the correct HMI model, and the Project Wizard will automatically generate the selected HMI screen. Analog quantities can be found in the WinCC Flexible software.

1. Open the simulation window of Siemens S7-200 PLC, and select Load Program in Program.

2. A new dialog box will pop up in the next step, which needs to be determined according to the settings shown in the figure.

3. If there is no problem at this time, just click the run button.

4. In this way, after obtaining the relevant renderings, the collected analog quantity can be converted.

Take 4-20mA as an example, first convert the taken signal into real numbers, the input is the address of the analog input point of the plc, and then customize an output point, for example, VD300, and then subtract 6400 from the block of sub di, which refers to the definition of 4mA as 6400, the output remains unchanged, and then use the Di r block to convert it, the input and output are all VD300, and then use the div r block to divide VD300 by a 25600, and finally use the mul The R block multiplies the range of your sensor by VD300 to output VD300, which shows the value that the sensor corresponding to 12mA should display.

You can access it directly at the AI point. Then you need to pid or other instructions to do it, and write the address of the corresponding point to OK