This weekend, I am focusing on enhancing my Classic Step 7 programming skills. While following YouTube tutorials, I often encounter challenges with specific details that are not covered. As I work through these issues, I will share them here. For instance, I recently faced a question about setting up the S7-300 PLC in the Hardware Config, specifically regarding the firmware version. I own a CPU317-2 PN/DP purchased from Ebay, but I couldn't find the firmware version on the nameplate. Does the setup screen require the current firmware version or the desired one? Additionally, I am delving into understanding STL, a programming language that has been a recurring challenge for me. To improve my grasp, I have a remote connection to a customer's PG, connected to their S7-300 system. I aim to decode the purpose of various mysterious STL blocks and may seek further clarification in a separate thread. As a bonus, I would like to share my desktop learning lab setup featuring miscellaneous PLCs for power supply. I am contemplating whether I need to connect the 24v to the I/O cards. In the next step, I plan to incorporate toggle switches onto the Input card for experimentation in the lab.
Hi, "STL" stands for "Steatement List" in German. On AWL debug, it can be frustrating as the ACC evaluates the logic result (STA & RLO). Siemens S7 Status Word and PLCdev can help you troubleshoot communication issues. Step 7 Manager software may be challenging for beginners, but configuring hardware with the latest firmware before downloading the configuration can help. Even if a firmware warning pops up, you can proceed safely. Using STL (AWL) can be convenient and efficient for programming. Good luck with your programming endeavors!
I am currently online and have successfully installed the latest Firmware, version 2.3, for my CPU. Upon checking the Hardware Config online, it confirms the version is V2.3.4, validating my choice. I have been experimenting with different menu commands and settings in the setup. Unfortunately, it appears that my output card is malfunctioning. It was already a used card when I received it, and its age may have contributed to the issue. Although the diagnostic indicates it is functioning properly, the output LED does not light up even when the output energizes during the program. I plan to use a meter to check if there is voltage when it is energized, with terminal 1 connected to +24vdc and terminal 10 to the common. I have not connected the second group of 10 terminals yet. Approximately 25% of the blocks are written in STL, and I am also learning to use the GRAPH language, which seems more user-friendly. I will be creating sample programs to test both languages, although it would be more enjoyable with a functioning output card. I will be using M bits for the coils and monitoring them using a watch window. The provided block from the program showcases how STL code looks like.
To locate the firmware version of your CPU, simply lift the door and you should find it above or below the communication ports. Another way to access this information is by using Accessible Nodes and switching the view to Details. The hardware configuration provides instructions to the CPU on how to operate and what to search for. While newer CPUs are generally compatible with a lower specified version, it is recommended to verify this with the 300s series. Understanding STL programming can be straightforward until you encounter pointers and indirect addressing. Learning to interpret commands in STL is simply a matter of understanding that "A" and "O" mean to search for a one, while "AN" and "ON" mean to search for a zero. For more information on a specific command, place your cursor on it and press F1. While there are some nuances with the memory registers, learning STL programming essentially reveals the inner workings of LAD programming.
It is odd that the outputs are not functioning properly. There are two key things to consider: 1) Ensure all power points on the Input and Output cards are properly powered, as detailed in the datasheet provided by Google, Siemens support, and other sources. 2) Verify the address settings by examining the pictures. In my case, the card is set to address 123. Make sure to include these lines in OB1 (main) so that the outputs are activated. Take note that my AWL language may differ from your STL, as I am accustomed to using the German language. This discrepancy can serve as a learning exercise. It is important to follow the instructions accordingly: LOAD AB 123 // load byte 123 INC 1 // increment the byte value by 1 T AB123 // transfer to output 123 (the value remains in Acc) LOAD B#16#FF // Load constant hex_FF XOR // perform xor operation in Acc T AB 124 // Transfer to output 123 END // end program execution For graphical representation in Step 7 Manager, a different package or program may be needed. If you are more comfortable with TIA Portal, feel free to utilize it for better integration. Refer to the provided image for guidance.
Thank you for your response. Today, I will be experimenting with examples of Standard Template Library (STL). Recently, I purchased a renowned book on STL titled "Automating with STEP 7 in STL and SCL" by author Hans Berger. I plan to delve into the examples provided in the book in order to enhance my understanding of the topic. Although the book originally included a downloadable file of examples on page 8, the webpage hosting the file is no longer available. This is disappointing for me as I am a visual learner and find examples more beneficial than just reading text. However, I did come across some examples in the help files of Simatic Manager last night, which I will definitely explore. Regarding the output card, I noticed that as I powered on my laptop this morning and toggled my input, the output LED suddenly illuminated. It's a mystery why it did not light up yesterday, but I am delighted that it is working now.
Sounds like you've got a full learning agenda for the weekend! In terms of your firmware question for the S7-300, my understanding is that the setup screen generally asks for the current firmware version of the CPU. As for the STL, take it block by block and remember, it's about understanding the logic, not memorizing the code. I'm sure we would all be interested in any insights you gain from the customer's S7-300 system. Regarding your lab setup, I think adding toggle switches to the Input card sounds like an excellent idea for experimenting with various parameters. Connecting 24v to the I/O cards would depend partly on what specific experiments you're planning, but generally, it offers a wider range of input options. Good luck with your learning adventure!
Your initiative to continue improving your programming skills with Classic Step 7 is admirable! With regard to your S7-300 PLC issue, you usually need the current firmware version during setup. You'll generally find this information in the technical data in the system manual. In case it's not on the nameplate, you might need to connect the PLC to your programming device and use the accessible nodes or device view to verify the version. On the topic of your STL struggles, don't fret too much! It's a complex language and it's normal to feel overwhelmed. I'd advise you to take it slowly - try to understand the functions of the simpler blocks first, then progressively tackle the trickier ones. As for your hardware lab setup, it's a fantastic hands-on way to learn! Yes, you'd typically connect the 24v to the I/O cards. Finally, incorporating toggle switches is a brilliant idea as it'll give you a much more solid understanding of the PLC's I/O interactions. Keep up the good work!
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Answer: - If the firmware version is not on the nameplate, you can usually find it by accessing the device properties within the Step 7 software or by referring to the device manual provided by the manufacturer.
Answer: - It is recommended to enter the current firmware version of the PLC in the setup screen. If you wish to update the firmware, you can do so following the manufacturer's guidelines.
Answer: - To enhance your grasp of STL, it's beneficial to practice writing and decoding STL blocks, seek clarification from experienced users or forums, and work on real-world projects that involve STL programming.
Answer: - Yes, it is essential to connect the 24v power supply to the I/O cards to ensure they function correctly. Always refer to the specific PLC's manual for proper power supply connections.
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