6.1 Teken 'n volledig benoemde diagram van 'n PLB-skandersiklus - NSC Electrical Technology Power Systems - Question 6 - 2021 - Paper 1

1. Flexibility: PLCs are more flexible compared to fixed relay systems. Changes to the control program can be made without rewiring.

2. Space Efficiency: PLCs require fewer components (like relays and timers), which makes the control system more compact.

It is important to check the PLC configuration and connections for:

1. Preventing Errors: Ensures all connections are correct to avoid malfunction.

2. Safety: Guarantees that the system operates safely under various conditions.

A PLC system is safer during fault conditions because:

• Monitoring Capabilities: PLCs can continuously monitor their own performance and can provide diagnostics to identify faults.
• Automatic Safety Protocols: PLCs can implement safety protocols automatically, which may be more reliable than manual intervention in a hardwired system.

The central processing unit (CPU) in a PLC is responsible for executing the control program logic and processing inputs and outputs. It interprets input signals, processes them according to the program, and sends commands to output devices.

Soft PLCs are software-based solutions that run on standard computer hardware. They can perform similar functions to hardware PLCs, providing flexibility and ease of modification.

PLC software is used to create and simulate control programs before implementation. This software helps in debugging and allows for easier updates and changes to the control programs.

1. Analog Signal: Represents data in a continuous flow. It can take any value within a range, making it suitable for measurements like temperature or pressure.

2. Digital Signal: Represents data in discrete steps or levels, typically as binary values (0s and 1s). Digital signals are more resistant to noise and interference.

Markers (or flags) in PLC programming are used to store temporary states. They can easily be set or reset within the program to control flow.

Contactors are used in PLC programming to control high-power devices. They act as electrically operated switches to manage the connection of loads.

A sensor is a device that detects environmental conditions and converts this information into an electrical signal for processing. Sensors can monitor temperature, light, motion, etc.

1. Temperature Sensors: Measure temperature variations.
2. Light Sensors: Detect light intensity changes.

1. Object Detection: Used in automation to detect the presence or absence of an object.
2. Safety Applications: Implemented in safety interlock systems to prevent accidents.

The PLC ladder logic diagram should replicate the functionality of the hand sequencer shown in the figure. It would typically involve rungs representing the sequence of operations with conditions based on the state of inputs and outputs.

1. Timers: Used to delay operations or create time-based controls.
2. Counters: Count occurrences of input signals for control processes.

The working sequence involves:

1. Initial conditions being set.
2. The circuit checking the status of inputs.
3. Executing the defined logic based on input states.
4. Output being activated or deactivated accordingly.

1. Solid-State Relays: Used for rapid switching of inductive loads.
2. Contactors: Electromagnetic switches that control high-voltage or high-current loads.

Figure 6.14 illustrates a regenerative braking system with relevant components like the variable speed drive and braking resistor.

The braking resistor dissipates excess energy generated during braking, converting it into heat to prevent damage to the system and maintain control.

Regenerative energy is utilized by capturing the energy normally lost during braking and feeding it back into the power supply, enhancing overall energy efficiency.

Block A is typically referred to as the Drive Controller, which regulates the operation of the motor based on input commands.

The main component used in telemetry is the Data Acquisition System, which collects and processes data from various sensors.

The inverter converts DC power into AC power, allowing control of motor speed and direction, thus enabling variable frequency drive (VFD) applications.

1. Controlling Motor Speed: Adjusting speed based on operational requirements.
2. Energy Saving: Reducing energy consumption by optimizing motor operation.