Welcome to the third part of our series on how to control a Variable Frequency Drive (VFD) with a Programmable Logic Controller (PLC). In this installment, we will focus on configuring a Siemens VFD to communicate with a Rockwell ControlLogix PLC. If you haven’t already, make sure to check out parts 1 and 2 for a complete understanding of the process.
Setting up the Siemens VFD
To begin, we will connect a laptop to the Ethernet port on the Siemens VFD using a non-crossover Ethernet cable. Once connected, we’ll ping the IP address of the VFD to ensure a successful connection.
Next, we’ll launch the Siemens SINAMICS STARTER program by double-clicking on its icon. This program allows us to configure and control the VFD.
Configuring the VFD
After launching the program, a pop-up display will appear. Select the “STARTER Project Wizard” to begin the configuration process.
In the Project Wizard, choose the option to arrange drive units offline. Enter a name for the project, such as “RealPars_VFD,” and proceed to the next step.
In the PG/PC set interface tab, select the USB interface. This interface allows the program to communicate with the VFD. Continue to the next step.
In the Insert drive units tab, choose “Sinamics” as the device type. From the drop-down menu, select “S120 CU320-2 DP” as the specific type of drive. Enter the target device address as 3, which is the PROFIBUS device address assigned in part 2 of this series. You can also provide a name for the drive, such as “Pump.” Add the drive to the project.
Once the drive is added, we need to include input/output components and a drive device to control the motor. Expand the “Pump” folder and double-click on the “Insert input/output components” folder. In this window, name it “RealPars_IO” and select “TM31” as the drive objects type. The TM31 is a terminal expansion board that increases the number of available digital and analog inputs/outputs within the drive system.
Next, double-click on the “Insert drive” folder under the Drives section. Enter the name “RealPars_Drive_1” for the drive under the General tab. Choose “Vector” as the drive objects type. Assign the drive object number as 3 and click OK.
In the Control structure configuration display, leave the control type as “encoderless speed control.” Continue to the next step.
In the next display window, change the component name to “Motor_Module” and select “Cabinet modules” as the type. Choose the appropriate power unit from the list. Leave the other fields as they are and proceed.
Configure the drive properties by selecting the NEMA motor and setting the connection voltage to 700 volts. Choose the appropriate power unit application based on the load duty cycle. Click Next to continue.
With this, we conclude the VFD configuration using the Siemens STARTER software. In the next part of this series, we will delve into configuring the type of motor and its nameplate data.
FAQs
Q: Can I use a different type of drive with the ControlLogix PLC?
A: Yes, you can use different types of drives with the ControlLogix PLC. However, the configuration and setup process may vary.
Q: How do I know if the VFD is successfully communicating with the PLC?
A: You can monitor the communication status and check for any error codes or messages in the Siemens STARTER program.
Q: Is it necessary to use the HMS gateway for communication between the PLC and VFD?
A: Yes, the HMS gateway is used to convert the ControlLogix CIP protocol to the Siemens PROFIBUS protocol, enabling communication between the devices.
Conclusion
Configuring a Siemens VFD to work seamlessly with a Rockwell ControlLogix PLC is an essential step in building a reliable and efficient control system. By following the steps outlined in this article, you can successfully establish communication between the devices and control the VFD from the PLC.
Remember, if you need more information or assistance with Rockwell processors, HMS gateways, or Siemens Robicon VFDs, feel free to reach out to us at Techal. Stay tuned for the final part of this series, where we will delve into motor configuration and nameplate data.
