This part of document only provides brief definitions of the key terms and concepts that is just a part of the complete document. You may download the complete document from our website just by clicking on at bottom of this document.
Symbol if it is a PDF file.
Symbol if it is a ZIP file.
What is a “Human Machine Interface (HMI)” device?
HMI stands for Human Machine Interface. This is the interface between the operator and the controller. The HMI is the controller operating panel. The panel comprises a numeric keypad and a LCD screen that displays text. The keypad is used to input data into the application, such as Timer values. The PLC’s Display screen can show operator messages, variable information from the program and system information….
Typical HMI screen design software allows us to perform different functions to design different control screens. HMI messages are created in the Display Editor.
Variable information fields are created in the Variable Editor.
In general, most typical HMI screen design software allows us to perform following function easily:
Creating and Naming a Display, Creating a fixed text Display, Creating Variables
In this document, we are going to design 2 HMI sample screens to demonstrate how we may take advantage of PM Designer software to design simple yet beautiful screens for our PLC projects.
How to start designing with PM Designer software
PanelMaster Company has developed a software name PM Designer which is free and can be downloaded from internet to be used to designer screen application programs for their HMI device.
As a programming example, let’s see how to RUN PM Designer to edit a simple program with few elements such as the START, STOP pushbuttons and of course later we will interface it to a PLC.
We can connect the device to a PC using either COM1/COM3 or USB ports seen on the figure 1. In doing this example, I used USB port to program it.
After the software is RUN, click on FILE >NEW and do the following settings. See figure 2
When the New Project dialog box appears, type in Project Name and “Location” where you want the file to be saved. See figure 3.
Click on Next > icon to go to the next dialog box. Type in your Application Name, Display Size in our case it is 7.0, and other information as seen in figure 4. At the end when clicked on “Next >”, you will be directed to the next dialog box as shown in figure 4.
In New Link dialog box, fill out the information as shown in figure 5 and at the end click on Finish icon. See figure 5.
See figure 6. In figure 6, “Screen 1 (#1) is the area where we can start editing our first HMI file.
Now, should we decide to change some setting such as Baud Rate, PLC and Panel address, we can do so by clicking on “Link 1” as shown in figure 7.
Figure 8, shows that some data which has been used to establish communication between “device” and the PLC has been selected.
When you Run PM Designer setup software for the first time, it installs related software that is needed to establish communication between device and PC automatically and you do not need to be worry about these communication parameters anymore.
Based on brand and model of our PLC which we are going to use in this project, we select “parameters” that in “Link Properties” dialog box as shown in figure 8 and at the end, click on “OK” icon.
To select and bring out any device image, you can click on Draw > Picture. See figure 9.
At of bottom of the figure 9, notice you have two options:
1- To import from Library.
2- To import from file.
PM Designer has lots of different symbols for pushbuttons, sensors, motors etc that we can use them in our design. See figure 10 for the list of the devices.
To select a picture as a background, simply, from the PM Designer dialog box, click on Screen and then from Screen Properties dialog box, click on Background tab, to select the “color” or “picture” you want to use in your design. See figures 11 and 12. Figure 11 displays how a motor “symbol” is chosen and placed on the design edit area.
Developing our first sample “HMI” program
Solution to the Sample exercises in this section can be found from the following folder and subdirectories provided that you have purchased any of my PLC based project titles. BUT don’t be worry; codes developed for all of the application programs are also included in this document or the download file.
As of our second sample program, let’s write a PLC control program which accepts 4 inputs signals from different pushbuttons to control a 3 phase motor to function as following: When S2 is depressed; motor starts running (STAR connection) and clockwise (CW) direction. When S4 pushbutton is depressed, STAR connection changes to DELTA. To change the connection, motor must be stopped first using S1 pushbutton and then when S3 is depressed, the direction changes from CW to CCW. Depressing S4, changes the connection configuration from STAR to DELTA.
Figures 13 and 14 display the control circuit diagram and Ladder Logic program of the problem respectively.
Now we need to write an HMI program to show all pushbuttons and also select an image as our “background” one on its screen.
To select S1 to S4 pushbuttons, we can use “Bit Button” symbols. See figures 14 and 15.
From PM Designer > Bit Button to open Bit Button dialog box to choose 4 buttons and to set their properties.
4 pushbuttons are placed on the designed area to simulate S1 to S4 as shown on figure 16.
From Bit Button dialog box, we can click on “Shape” icon to specify the shape of the buttons. See figure 17.
Also from Bit Button dialog box, we can specify parameters such as BG Color, Border Color, Pattern and FG Color for any of the buttons we need to use in our design. See figure 18.
Since we need to use S1 to S4 symbols as pushbuttons, on Bit Button dialog box, click on “Set ON Pulse” option in “Operation” section.
In the “Write Address” section, address related to S1 is typed which would be “M 0.0”. See figure 18.
From Bit Button dialog box > Label tab, we can chose a suitable name and image for the any of the button we have. See figure 19.
By repeating the same steps, we can choose how our other pushbuttons need to be supposed to look, or named or function etc. See figure 20.
To display to show any messages on our HMI screen when it is operating, we can use Message Display dialog box to specify the messages. See figure 21.
From the Message Display dialog box click on Visibility tab to specify address of the message you want to be displayed. On figure 22, notice that Controlled by Bit is clicked and is set to q3.1 which means any time output bit q3.1= 1, Motor Turn Left message will be displayed as long as K2 (from figure 13) = q3.1 is high or = 1.
Figure 23 displays our design screen so far.
To show if motor is revolving CW or CCW, I used two animate pictures to serve the purpose. As an example, to show CCW direction, I can select to place a small image by taking following steps. See figures 24, 25, and 26.
Figure 27 shows what we got so far.
And in the end of the process, we need to save and compile the program. In figure 28, by clicking on icon number 1, you can compile your file and number 2 download it to the HMI’s memory and it would executed automatically.
Figure 29, displays the final HMI screen design would be shown when you download and executed software developed V1.1 software.
To be continued in the download file!
Click below icon to download the whole document