Good evening, everyone. Here I'll continue sharing knowledge about MODBUS communication, specifically communication between touchscreens and frequency converters. Previously, I shared the two steps required to achieve communication between a touchscreen and a frequency converter :
(a) Selection of communication driver in touch screen
(ii) Establishment of variables in touch screen
Today we continue to share tips on touchscreen layout and configuration.
III. Touchscreen Layout and Tips
When configuring Siemens touchscreens, you can copy images directly to the touchscreen. For example, if you use text to write names on a Siemens touchscreen, the font options are limited. The same applies to buttons and numeric input/output displays; relying solely on the components provided in the touchscreen software is insufficient. In such cases, you can create the image externally, take a screenshot, and copy it to the touchscreen screen, such as by creating a screenshot from a PowerPoint presentation and copying it in. See the image below:
The entire screen content here was created in PowerPoint, and then a screenshot was uploaded. When taking the screenshot, pay attention to the consistency of the size.
After the screen is completed, configure the corresponding buttons, numbers, and status displays, as shown in the image above. Place a button on each externally created button, select "invisible" for the button, and then configure the button as shown in the image:
The same approach is used for numerical displays. When selecting a style, you can choose "No Style," which will prevent borders from appearing in the data display area. For motors, you can select motors of different colors and configure the display of different images based on the numerical value in the dialog properties. When images are superimposed, ensure they are set to the same size and position in the layout. As shown in the image, three motors of different colors are superimposed to represent different motor states.
IV. Variable Connections and Configuration in the Screen
In this screen, besides the status display configuration mentioned above, the most important thing we need to configure is the forward and reverse rotation of the motor, the stop button, the frequency input and output, and the display of voltage and current output.
(1) Button configuration
Controlling the inverter requires clicking a button. After clicking the button, the corresponding command code value needs to be written to the Modbus information register address of the inverter. Therefore, button operation is not a simple bit control. In this case, when selecting the event function, we cannot choose the bit editing function as in the bit control method of PLC. Instead, we should choose the function for inputting the value, as shown in the figure below:
Similarly, for reversal, the stop button simply requires writing different values into the control command.
(2) Frequency and voltage/current input display configuration.
Let's take input frequency as an example. In a previous article, we saw that the input frequency has two decimal places, meaning the frequency resolution is 0.01 Hz . That is, if you input a value of 3000, the input frequency is 30.00 Hz. But do we need to perform any calculations on the touchscreen? Do we divide the input number by 100? Here, we don't need to do any calculations; we just need to move the decimal point. As shown in the image:
