Hello, I will be working on a project involving the CPU 315 series which will be connecting to various slave devices like ABB drives, power meters, and soft starters via the Modbus master RTU protocol. I am in need of a sample project or template for this type of project. Specifically, I am facing difficulties with write function codes such as FC06 in terms of configuring the data structure of the related DB and creating logic for FC06 to periodically write on the slave devices. Please provide me with a sample project and a detailed document explaining this process. I am using Simatic Manager v5.6 and my issue lies within Simatic, not TIA PORTAL. It seems that modbus RTU300 master programming can be complex compared to TIA PORTAL. Thank you for your assistance.
Unfortunately, the Siemens S7 300 does not have direct support for Modbus RTU communication protocols.
If you're looking to install MODBUS RTU libraries, this guide could be a valuable resource. You can access the manual for setting up these libraries at https://cache.industry.siemens.com/dl/files/141/47756141/att_949029/v1/47756141_Description.pdf.
Utilizing Modbus RTU Protocol for Master-Slave Communication on Siemens S7-300 PLCshttps://support.industry.siemens.com/cs/attachments/109474714/109474714_S7300_ModbusRTU_DOC_v1d1_en.pdf Improved Version: Maximizing Siemens S7-300 PLC Efficiency with Modbus RTU Protocol for Master-Slave Communicationhttps://support.industry.siemens.com/cs/attachments/109474714/109474714_S7300_ModbusRTU_DOC_v1d1_en.pdf
A Modbus RTU connection using a CP series serial card requires a separate license. However, utilizing the newer ET200SP Profinet cards on a separate IM-island eliminates the need for a Modbus license. Additionally, you have the option to use a 1200CPU in between devices and program them with TIA Portal, but S7 data exchange is necessary between the 300 and 1200 series.
I am using a CPU 315 2PN/DP with a CP341 card to communicate with ABB drives. Unfortunately, Siemens S7 300 does not directly support Modbus RTU. However, with the CP341 and a dongle, I am able to establish communication.
Hi there, I understand your struggle with Modbus RTU300 master programming in Simatic Manager. It can indeed get complex. Unfortunately, I don't have a direct sample project with me right now. However, I do suggest that you check out the Siemens Industry Online Support website. They have various application examples that explain how to define and configure function codes in detail. If you dig around a bit, you might find something that could help you with FC06 configurations. Additionally, utilizing the Simatic S7-300 CPU manual can give a comprehensive understanding on data structure configurations. If you still need specific details, please let me know. I'd be keen to help you brainstorm solutions to overcome your hurdles.
Hey there, it sounds like you've got quite a task ahead of you. Unfortunately, I don't have a sample project I can share offhand. However, a general approach in handling FC06 would be to assemble a data structure in your DB that mirrors the Modbus request (device address, function code, register address, and data), and then call an FC to transmit this request over the communication network at a fixed interval. This manual process confers better control, which is sometimes needed when working in Simatic manager environment because of its inherent complexity. For a more hands-on guide, training materials from Siemens could be beneficial, if you haven't already tried them. Also, there are plenty of valuable resources, tutorials, and even forums online dedicated to Simatic that you might find helpful. Keep digging and don't lose hope, you'll get there!
I understand that configuring the data structure for FC06 and creating the logic to periodically write on the slave devices can be a bit challenging in Simatic Manager v5.6. Unfortunately, I don't have a sample project on hand, but I can certainly guide you through some steps. Firstly, the DB for FC06 would contain the starting address, the number of registers, and the actual holding register data. Regarding the routine for periodic writing, you'd typically create an OB (e.g. OB35) that is triggered based on your cycle time. This OB should call an FC that encapsulates the Modbus write mechanism. Although I agree that programming Modbus RTU300 master in Simatic Manager can be more complex than TIA Portal, it offers a higher degree of versatility. If time permits, I recommend going through Siemens' manuals for the Modbus RTU protocol, specifically focusing on Function Code 06 for starters. They're comprehensive and can provide insights into how data structure is interpreted within this system. Good luck with your project!
✅ Work Order Management
✅ Asset Tracking
✅ Preventive Maintenance
✅ Inspection Report
We have received your information. We will share Schedule Demo details on your Mail Id.
Answer: Answer: The CPU 315 series can connect to various slave devices like ABB drives, power meters, and soft starters using the Modbus RTU protocol.
Answer: Answer: The specific difficulty mentioned is related to configuring the data structure of the related DB and creating logic for FC06 to periodically write on the slave devices.
Answer: Answer: The project is using Simatic Manager v5.6, and the issue lies within Simatic, not TIA PORTAL.
Answer: Answer: It seems that Modbus RTU300 master programming can be complex compared to TIA PORTAL, as per the user's experience mentioned in the thread.
Join hundreds of satisfied customers who have transformed their maintenance processes.
Sign up today and start optimizing your workflow.