MasterTool IEC XE - 6 - Uso de entradas analógicas

Summary

This video guides viewers through the process of configuring analog inputs in a PLC system, covering three types of input signals (0-10V, 0-20mA, and 4-20mA). It demonstrates how to set up these inputs, including the option to apply digital filtering to reduce noise. The tutorial explains how to use these analog signals in PLC programming, utilizing functions like 'Moving' to store values and perform comparisons. The video also covers mathematical operations for scaling the analog values, followed by running simulations to visualize the input-output relationships, ultimately showcasing the practical use of analog signals in automation.

Takeaways

• 😀 The script explains how to configure analog input signals in a PLC system, including voltage and current ranges like 0-10V, 0-20mA, and 4-20mA.
• 😀 It emphasizes the importance of selecting the correct input nature for analog signals, such as voltage or current, to match specific sensor outputs.
• 😀 Digital filtering is introduced as a way to reduce noise in analog signals, with options for different filtering durations (e.g., 100ms, 1s, 10s).
• 😀 Analog inputs are converted into digital values that the PLC can process, with specific calculations for voltage-to-digital conversions based on the input range.
• 😀 The script illustrates how to create and use variables in the PLC program to store analog input values and apply mathematical comparisons (e.g., greater than or less than).
• 😀 A practical example shows how to set up a threshold voltage (e.g., 1.5V) and use it in the program to trigger actions based on the comparison results.
• 😀 The script demonstrates how to continuously move or copy data between variables using the 'Moving' block to ensure real-time processing.
• 😀 Users are guided through the process of running simulations to test the program logic and verify that the configured inputs work as expected.
• 😀 The simulation interface is highlighted, allowing users to monitor real-time input changes and observe the corresponding behavior of the program.
• 😀 It is explained that different types of analog inputs (voltage and current) might have different scaling behaviors, and users need to adjust logic accordingly (e.g., for current signals, using a linear relationship).

Q & A

What is the main purpose of the video?

The main purpose of the video is to demonstrate how to capture and process analog signals in a control system, specifically using a CLP (Programmable Logic Controller) and configuring its analog input parameters.

What types of analog inputs can the specific CLP model handle?

The specific CLP model can handle three different types of analog inputs: voltage (0-10 volts), current (0-20 mA), and current (4-20 mA).

What does configuring the analog input involve?

Configuring the analog input involves setting the nature of the signal, such as the voltage or current range, and enabling options like digital filtering to smooth out noise or interference from the signal.

Why might digital filtering be necessary when working with analog signals?

Digital filtering is necessary to remove noise or interference (referred to as 'signal noise') from the analog signal. It smooths out the signal, making it more stable and reliable for processing.

What is the trade-off when enabling digital filtering on the signal?

The trade-off when enabling digital filtering is that while the signal becomes less noisy and more stable, it also responds more slowly due to the filtering process. Fast-moving variables like sensor positions may need to be read without filtering.

How are the analog signal values transformed in the CLP?

When analog signals are read by the CLP, they are converted into digital values. For example, a voltage input of 0-10 volts is represented as a range of values from 0 to 30,000, corresponding to the voltage levels.

How does the logic for comparing an analog input value work?

To compare an analog input, you convert the signal value (e.g., from 0-10 volts) into a digital integer. Then, using comparison operators, you can check if the converted value is less than, greater than, or equal to a specified threshold.

What is the role of the 'move' function in the program?

The 'move' function in the program is used to continuously transfer the value from the analog input (e.g., voltage or current) into a variable for further processing or comparison in the program.

What happens if the input value is less than or greater than the threshold in the logic?

If the input value is less than the threshold, the comparison is false, and the output remains inactive. If the input value exceeds the threshold, the comparison becomes true, activating the corresponding output (e.g., a coil or event).

How is the value for the comparison calculated in the example with voltage?

In the example, the comparison value is calculated using a simple rule of three. For a sensor reading of 1.5 volts, the corresponding digital value is calculated as 1.5 multiplied by 30,000, divided by 10 volts, resulting in 4,500.