Looking for help with integrating Eztouch HMI EZ3-T6C-EE, Allen Bradley 5/03 PLC, 1746-NIO4V Analog in/out, and Altivar 31 VFD? As a newcomer to this field, I have the necessary software like Rslogix 500, Rslogix5000, Studio5000, and RSlinx. However, I am facing a challenge in controlling the VFD speeds using the HMI. The original program used to control the speeds, but now they are set directly on the VFDs. My task is to use the HMI to regulate the speeds effectively. I am seeking guidance on how to set up the HMI for speed control. My idea is to have a numeric input on the HMI screen to adjust the speed within the range of 0-60 Hz. However, I am unsure about where to write this value to the PLC - B file or N file. Additionally, I have been exploring the SCP instruction on the PLC, but I am not fully confident in my understanding. I created a test program using the SCP instruction, but encountered issues when inputting values beyond a certain range. If anyone can provide assistance or guidance on how to establish the communication between the HMI and the PLC for speed control, I would greatly appreciate it. Thank you for your help in advance!
I encountered a challenge while implementing an idea involving automatic and manual speed control on a system similar to AB, but with minor variations. The concept revolved around setting a speed reference using a tag named DRIVE_1_Speed for a scaling block. Two additional tags, DRIVE_1_Auto_Speed and DRIVE_1_Man_Speed, were used to store the automatic and manual speed values, respectively. On the HMI interface, there was a button for toggling between auto and manual modes. The programming logic involved moving the values from either DRIVE_1_Auto_Speed or DRIVE_1_Man_Speed to DRIVE_1_Speed based on the status of the auto button. Essentially, the system would transfer the speed value from a predefined recipe when the auto mode was active, or input the manual speed set on the HMI when the auto mode was inactive. If you are experiencing issues with the value, ensure that the HMI tag is configured correctly as an integer type to prevent potential errors.
The HMI setpoint is used to update multiple files in the PLC, such as N7:0. The SCP instruction is responsible for adjusting this setpoint to a range of 0-32767 to control the analog card's output voltage from 0-10v to the VFD. With six parameters, the SCP instruction includes the following: Input (HMI setpoint - N7:0), Input Min (N7:1 - 0), Input Max (N7:2 - 60), Output Min (N7:3 - 0), Output Max (N7:4 - 32767), and Output (analog output card address for VFD control - O:4.0 for slot 4, channel 0).
I believe you're on the right track with wanting to use the SCP instruction, especially since it's such a powerful tool for handling analog outputs. As for where to write the value, this all depends on your PLC set up and software. Normally, it could go into an N file corresponding to the analog output address in your PLC to regulate the VFD speeds. What you should do is map the HMI's numeric input to this address. Be sure you properly scale your output in the SCP instruction to match the 0-60 Hz speed range you're aiming for on your VFD. If you're still encountering issues beyond a certain speed, you might need to debug your program by evaluating your analog output scaling and checking if your speed control on the VFD is configured correctly. Keep persisting, as these tasks always come with a learning curve!
Hey there! It's great to see you working hands-on with these systems. The key to your problem lies in understanding how data is communicated between your HMI and PLC. You can indeed use the N or B file, but since you're dealing with speed (which is a numeric value), utilizing the N file would be more suitable in your case. As for the SCP instruction, think of it as a proportion scaling mechanism - it's used to scale the input value into a range suitable for your output device, the VFD in this case. You might want to look into adjusting the SCP instruction's parameters if you're encountering range issues. However, do make sure that your VFD is configured to accept speed control commands as an analog input from PLC. Keep experimenting, you're on the right track!
The first thing that comes to mind is to ensure that your HMI and PLC are communicating accurately. In order to control the VFD speed using the HMI, you need to write the desired speed value to the respective tag or register in the PLC that communicates with the VFD. Regarding where to write this value, typically N file could be used for storing this data. You can make the HMI numeric input to write a value within the required Hz range into the selected register. For the SCP instruction, think of it as a simple scaling solution that allows a large range of values to be converted into a small range, preventing input overflows. Your range of input "Raw Min to Max" should be coming from your HMI (0-60Hz) and the "Scaled Min to Max" would be what the VFD understands. Just ensure your input values match the range defined in SCP. Misdefinition of the ranges could be causing the issues you mentioned. This is a high-level way to approach your problem, but specifics could vary based on exact setup details, so experimentation might be a part of the process. Good luck!
It sounds like you're facing a classic integration challenge! For controlling the VFD speed via the HMI, you’re on the right track with the numeric input. You’ll want to map that value from the HMI to the correct data file in the PLC—typically, you could use an N file for analog values like frequency since it deals with integers. The SCP instruction is great for scaling your input from the HMI to the appropriate range for the VFD, but make sure you set your MIN and MAX values correctly based on your requirements (remember to consider the possible output limits of the VFD). If you’re running into issues with values outside a certain range, double-check the scaling parameters and ensure your HMI is sending the decimal or integer format expected by the PLC. Debugging with the Monitor function in RSLogix can really help you see what values are being read. Good luck, and feel free to share updates or further questions as you go along!
It sounds like you're on the right track with your approach! For controlling the VFD speed through the HMI, you’ll want to focus on writing the speed value into the appropriate data file in your PLC. Typically, numeric values would go into the N file (like N7 or N15, depending on your system setup) since that's where your analog data typically resides. For the SCP (Scale with Parameters) instruction, ensure that the input values are within the expected range for both the source (HMI) and the destination (VFD), as that’s often where issues arise. Also, double-check that your HMI is correctly set up to send the values to the PLC in real-time. You might need to adjust your communication settings in RSlinx to facilitate proper data flow. Don't hesitate to utilize forums or resources specific to Allen Bradley and Schneider Electric for additional tips on your VFD configuration as well!
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Answer: - To integrate these components for speed control, you will need to establish communication between the HMI, PLC, and VFD. Ensure you have the necessary software like Rslogix 500, Rslogix 5000, Studio 5000, and RSlinx. You can use numeric input on the HMI screen to adjust the speed within the desired range.
Answer: - The speed value from the HMI can be written to either the B file or N file in the PLC, depending on your programming preferences and the structure of your PLC program.
Answer: - To set up the HMI for speed control, you can create a numeric input on the HMI screen to adjust the speed within the range of 0-60 Hz. Ensure that the HMI is properly configured to communicate with the PLC and VFD.
Answer: - The SCP (Set Control Parameter) instruction on the PLC can be used for setting control parameters such as speed values. It is important to understand how to properly use this instruction to ensure effective speed control between the HMI
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