How To Trigger Robotic Arm Trough Plc?

Setting up a robotic arm with a PLC might sound complex, but it’s easier than you think. From configuring IP addresses to wiring digital inputs and outputs, every step plays a role in creating seamless control. Ready to explore how to make your robotic arm respond flawlessly to your commands? Keep reading!

Robot Arm Hardware Setup and Configuration

Network Setup

• Ensure the robotic arm and PLC are connected to the same network. Use a wireless router if the robotic arm supports Wi-Fi and the PLC uses Ethernet.
• Assign a static IP address to the PLC through router settings or a network administrator. Limit the DHCP range to secure static addresses.

Robotic Arm Wi-Fi Configuration

• Connect the robotic arm to a PC via USB. Open the Configure App, select USB as the communication mode, and click “Go” to set up Wi-Fi.
• Use the Robot Arm V2 Control Apps to confirm the robotic arm is on the same network as the PLC.

PLC IP Address Assignment

• Open the project framework in Siemens TIA Portal. In the Devices tree, find the PLC, select Online and diagnostics, and scan for the PLC using the Accessible Devices option.
• Assign an IP address to the PLC and confirm the connection using the Flash LED option to identify the correct device.

Digital I/O Configuration

• Assign rack, slot, and channel numbers to Input/Output (I/O) points. For instance, map a 16-channel input card and a 16-channel output card to specific rack slots.
• Connect the PLC’s digital inputs to the robotic arm‘s digital outputs, and vice versa. Test the setup by toggling PLC output bits while observing the teach pendant’s Digital Input (DI) page.

Ethernet/IP Communication

• Configure Ethernet/IP communication between the PLC and the robot. For a FANUC robot and a Rockwell PLC, go to the host communication setup page, set the IP address, and initialize the connection. Ensure assembly instance details match (e.g., Input: 101, Output: 151, Configuration: 100).

Verification and Testing

• Use the PING command to check the connection between the PLC and the robotic arm.
• Restart the robotic arm’s controller and verify I/O functionality on the Monitor page by testing input and output operations.

Power Supply and Safety of Robot Arm

• Ensure a stable power supply to the PLC and robotic arm without voltage fluctuations.
• Implement safety measures, including emergency stop buttons, safety interlocks, and light curtains, to ensure secure operation.

Robot Arm Programming and Logic

Understanding PLC Programming Languages

PLC programming for robotics arm often uses ladder logic, function block diagrams, and structured text. These languages help programmers efficiently define a robotic arm’s behavior.

Ladder Logic Basics of Robot Arm

• Ladder logic is based on digital logic gates like AND, OR, and NOT:
  • AND Gate: Both inputs must be active for the output to work.
  • OR Gate: Uses branches to activate the output if either input is active.

The Program Scan Cycle

• In a Program Scan Cycle, the PLC continuously performs these steps:
  1. Reads inputs.
  2. Processes the ladder logic.
  3. Updates outputs.
• The scan time usually ranges from 1 to 20 milliseconds, depending on processor speed and program size.

Connecting PLC to Robotic Arm I/O Devices

The PLC interacts with the robotic arm’s input/output (I/O) devices, such as sensors, actuators, motors, and push buttons.
– Example: In a pick-and-place robotic arm, sensors and buttons guide the arm’s movements.

Programming for Various Operational Modes

Programs should support different modes, such as:
– Manual Control: Direct user input.
– Automatic Operation: Actions based on predefined logic.
– Example: A pick-and-place robotic arm can move objects from a conveyor belt to specific locations.

Input Logic with Switches of Robot Arm

• Normally Open (NO) Switches: Output 0V when idle and 24V when activated.
• Normally Closed (NC) Switches: Work oppositely, staying closed when idle.

Communication Protocols for Integration

Efficient communication between the PLC and the robotic arm uses protocols like:
– Ethernet/IP
– Modbus TCP
– Profinet
These protocols allow precise control and smooth integration.

Robot Arms Operation and Control

Signal Reception and Processing

• The PLC collects input from sensors like position, force, and temperature sensors. These inputs provide real-time data on the robotic arm’s condition.
• Logical algorithms process the signals to accurately understand the robotic arm‘s current and desired states.

Output Signal Generation

• The processed data enables the PLC to create precise output signals. These signals control components such as motors and cylinders, ensuring the robotic arm functions correctly.
• These signals are sent to the robot hand, allowing it to perform programmed tasks effectively.

Robot Arm Modes of Operation

Auto Mode

• In auto mode, the robotic arm operates independently, following pre-set instructions. It performs tasks without manual input.

Manual Mode

• In manual mode, operators control the arm using push buttons and DPDT switches. Limit switches prevent the arm from exceeding predefined movement boundaries, protecting the system from damage.

Control Mechanisms of Robot Arm

• Relays and Motors: Relays control the arm’s motions, such as moving up, down, left, or right.
• Input/Output Ports: Input ports handle actions like start, stop, and jaw open/close, while output ports directly control motor functions and other robotic systems.

System Integration and Advanced Algorithms

• The PLC works seamlessly with devices like conveyor belts and auxiliary machines to streamline production.
• Advanced algorithms, based on position and images, ensure accurate path planning, obstacle avoidance, and smooth motion control—key for high-performance operations.

Monitoring and User Interface

• A Human Machine Interface (HMI) simplifies system management. It includes features like alarms, fault recording, and data monitoring to enhance control and efficiency.

Power Supply and Wiring of Robot Arm

Shared Grounding

To ensure proper function and avoid voltage issues, connect the 0V/GND of the robot arm and PLC. Sharing the same ground creates a stable connection.

External Power Supply

If the robotic arm’s or PLC’s internal power supply is insufficient, use an external 24V power supply. For instance, Universal Robots controllers support this option. The external power supply can also power other components like PLCs and solenoids.

Current Management

Verify that the power supply can support the total current required by all components. When controlling solenoids, ensure the cable gauge matches the current demands.

Robot Arm Wire Separation

Keep power and signal wires separate to reduce interference. Twist power wires together to lower electromagnetic interference (EMI) and improve signal quality.

Digital I/O Connections

Connect the PLC’s digital outputs to the robot arm‘s digital inputs, ensuring both devices share the same 0V/GND. This allows seamless communication.

Modbus Configuration

Use the Modbus protocol for efficient communication. It reduces physical wiring by enabling multiple devices to connect over a single network.

Robot Arm Emergency Stop

Install an emergency stop mechanism using a relay or contactor. This system can cut power to motor controllers during emergencies, enhancing safety.

Fuses and Circuit Breakers

Protect the system from overcurrent by using fuses or circuit breakers rated for your system’s current requirements.

Connecting a Push Button

To set up a push button for starting a program: 1. Connect a wire from the +24V terminal in the digital input block to the button’s contact. 2. Connect another wire from the button’s other contact to the DI0 terminal.

Connecting an Indicator Lamp

To connect an indicator lamp: 1. Link the 0V terminal of the digital outputs to the lamp’s negative (0V) terminal. 2. Connect the DO4 terminal to the lamp’s positive (+24VDC).

Following these guidelines ensures a safe, reliable, and efficient wiring setup for your PLC-controlled robotic arm.

Specific PLC Configurations of Robot Arm

To control a robotic arm using a Programmable Logic Controller (PLC), proper setup is essential. Here’s a clear breakdown:

Mapping Input/Output (I/O) Connections

• Configure the PLC to map digital I/O connections to the robotic arm.
• Example: An Allen-Bradley MicroLogix 1100 PLC connects via a digital I/O connector bus.

Implementing Control Logic of Robot Arm

• Use ladder logic programs to control the robotic arm’s movements.
• These programs manage up/down and left/right motions with relays and limit switches.

Mode Selection: Manual and Automatic

• Switch between manual and automatic modes using configured switches in the PLC program.
• Normally closed switches make mode switching straightforward.

Precise Positioning with Potentiometers

• Potentiometers on the arm’s joints provide feedback for precise positioning.
• Example: A constant +10Vdc applied to each potentiometer provides analog voltage feedback, converted to digital by the PLC.

Robot Arm Motor Control via Relays

• Relays manage the robot arm‘s motor movements.
• Example: Two relays control up/down motion, while another two manage left/right motion with 12V motors.

Integration of Limit Switches

• Limit switches ensure the robotic arm stays within safe limits.
• The PLC stops the motor when the arm reaches predefined positions based on feedback.

Communication and Advanced Configurations

• PLCs communicate with robotic arms via Ethernet or digital I/O connections.
• Example: A Fanuc LR Mate 200iD robot connects to an Allen-Bradley MicroLogix 1100 PLC using digital I/O if Ethernet is unavailable.

Triggering Actions Based on Input Signals

• PLC programs trigger robotic arm actions based on input signals.
• Example: A vision system detects a part, activating a “good part” program to move the arm. The program resets after the action completes.

By mastering these setup and integration steps, you unlock the full potential of PLC-controlled robotic arms. With precise programming and careful configuration, seamless automation becomes a reality, empowering your projects to achieve efficiency, accuracy, and reliability. For more details or to get a quote, contact us today!