Steps to Add CP 343-1 Lean to Your Existing PLC

Adding a CP 343-1 Lean to your existing Siemens S7-300 PLC system (with CPU 314) requires careful configuration and setup. Below is a step-by-step guide to help you integrate the CP 343-1 Lean module successfully:


Steps to Add CP 343-1 Lean to Your Existing PLC:

1. Prepare Your Hardware:

  • Power Down the System: Turn off the power to the PLC rack before installing the CP 343-1 Lean module.
  • Install the CP 343-1 Lean: Insert the CP 343-1 Lean into an available slot in the S7-300 rack (slots 3–11). Ensure it is properly seated and connected to the backplane bus.
  • Connect Ethernet Cable: Connect an Ethernet cable to the CP 343-1 Lean module for communication with other devices (e.g., PC, HMI, or other PLCs).

2. Configure the Hardware in STEP 7:

  • Open your STEP 7 project in SIMATIC Manager.
  • Navigate to Hardware Configuration (HW Config).
  • Drag and drop the CP 343-1 Lean module from the hardware catalog into the appropriate slot in your rack configuration.
  • Double-click the CP 343-1 Lean module to open its properties.

3. Set the MPI Address and Parameters:

  • In the CP 343-1 Lean properties, configure the following:
    • MPI Address: Ensure the MPI address is unique and does not conflict with other devices on the MPI network (e.g., set it to 3, as you mentioned earlier).
    • Transmission Rate: Set the transmission rate to match the CPU and other devices on the MPI network (e.g., 187.5 kbps).
    • Ethernet Parameters: Configure the IP address, subnet mask, and gateway for the CP 343-1 Lean. Ensure the IP address is unique on your network.

4. Configure the Ethernet Interface:

  • In the CP 343-1 Lean properties, go to the Ethernet Interface settings.
  • Assign a static IP address or configure it to obtain an IP address automatically via DHCP (if supported).
  • Enable Industrial Ethernet (ISO protocol) or TCP/IP communication, depending on your requirements.

5. Compile and Download the Hardware Configuration:

  • Save and compile the hardware configuration.
  • Connect your programming device (PC) to the CPU via the MPI interface.
  • Download the updated hardware configuration to the CPU.

6. Test Communication via MPI:

  • After downloading the configuration, power on the system.
  • Verify that the CPU and CP 343-1 Lean are operating correctly (check LED indicators: RUN, DC5V, and Ethernet link).
  • Use STEP 7 to go online with the CPU via the MPI interface and check the diagnostic buffer for any errors.

7. Test Communication via Ethernet:

  • Connect your PC to the CP 343-1 Lean via Ethernet.
  • Use STEP 7 to go online with the CPU via the Ethernet interface.
  • Verify that you can access the CPU and monitor the program.

8. Adjust Startup Time (if necessary):

  • If the CPU goes to STOP mode during startup, increase the Startup Time parameter in the CPU properties.
  • Set it to a higher value (e.g., 1000 or 1200) to allow more time for parameter transfer to the CP 343-1 Lean.

9. Configure Communication Blocks (if needed):

  • If you plan to use the CP 343-1 Lean for data exchange with other devices (e.g., HMI, SCADA, or other PLCs), you may need to configure communication blocks (e.g., FB12/FB13 for TCP/IP communication).
  • Add the necessary logic to your program to handle communication tasks.

10. Verify System Operation:

  • Test the entire system to ensure that the CP 343-1 Lean is functioning as expected.
  • Monitor the diagnostic buffer and LED indicators for any issues.
  • Perform a test communication with an external device (e.g., ping the CP 343-1 Lean from your PC).

Troubleshooting Tips:

  1. CPU Goes to STOP Mode:
  • Check the diagnostic buffer for errors related to the CP 343-1 Lean.
  • Verify that the hardware configuration matches the actual setup.
  • Ensure the MPI address and transmission rate are correct.
  1. Communication Issues:
  • Verify the Ethernet cable and connection.
  • Check the IP address and subnet mask settings.
  • Ensure the CP 343-1 Lean is properly seated in the rack.
  1. LED Indicators:
  • RUN Green: Indicates the module is operating correctly.
  • SF Red: Indicates a system fault (check the diagnostic buffer).
  • Ethernet Link Green: Indicates a valid Ethernet connection.

Summary of Steps:

  1. Install the CP 343-1 Lean in the rack.
  2. Configure the module in STEP 7 (HW Config).
  3. Set MPI address, transmission rate, and Ethernet parameters.
  4. Compile and download the hardware configuration.
  5. Test communication via MPI and Ethernet.
  6. Adjust startup time if necessary.
  7. Configure communication blocks (if needed).
  8. Verify system operation and troubleshoot if required.

By following these steps, you should be able to successfully integrate the CP 343-1 Lean into your existing PLC system.