I am currently working on implementing a linear motion guide using a ball screw shaft driven by a stepper motor and controlled by a PLC system. The PLC model I am using is Omron CP1E-N30DT-A, and the stepper motor is a Nema 34. The main objective is to move the stepper motor in both clockwise and anti-clockwise directions. However, I am facing an issue where the stepper motor driver is not receiving any pulses from the PLC despite using the PLS2 instruction to generate pulses. Although the output lights on 100.00 and 100.02 are on, indicating that the outputs are active, the driver is not registering any pulses. I have connected the PUL- to 100.00 and DIR- to 100.02, with PUL+ and DIR+ connected to a positive 24V with a 2k resistor. The common port for 100.00, 100.01, and 100.02 is connected to a negative 24V. Any assistance or advice on resolving this issue would be greatly appreciated. Thank you.
Before purchasing a PWM driver module, it's essential to ensure it is a source and operates at 24v. Many available modules are typically 5v and function as sink, so be certain to confirm the specifications before making a purchase.
I believe the PLC output is sinking due to the common ground being negative.
Certainly, the power is supplied to a pin on the drive module, with the PLC common being 0V. The compatibility can vary depending on the drive in use. For instance, I encountered issues with a PWM drive module where the input is 5V sinking and the PLC is normally 24V sinking. This caused intermittent functionality as the sinking outputs were only pulling down to around 2.4V instead of 0V. It is important to note that the inputs are effectively being pulled down in this setup. A useful tip is to try reducing the PWM to a slow, long pulse to accurately measure the output pulse from the PLC.
Upon analyzing the pulse output of the PLC, I noticed that the voltage remains steady at 24V when the output is off. However, when the pulse output is activated, the voltage drops to 12V and remains constant. Ideally, it should fluctuate between 24V and close to 0V. I believe this discrepancy is the main issue at hand, but I am unsure of the proper solution. How can I rectify this issue with the fluctuating voltage output from the PLC?
To ensure proper functioning of PLC's transistor outputs, it is necessary to address the issue of heavy loads. I encountered the same issue and resolved it by adding resistors in the supply to the PWM card for the inputs and in the PLC output to 0v. This tactic successfully created a load, allowing the inputs on the PWM card to operate effectively. It is essential to note that the inputs on a PWM card have high impedance and require minimal current draw to function optimally.
It seems like you've got your wiring in order, but the problem might be in your PLC or Motor Driver settings. Since the output lights on 100.00 and 100.02 are on, it indicates that your PLC is working. I suggest you check the settings of your motor driver too, specifically, the pulse signal receiver setting. Make sure it aligns with the pulse output from the Omron PLC. Furthermore, you might want to ensure that the PLC is set to give "pulse train output" since you are using a stepper motor. If the problem still prevails, try communicating with your PLC through CX programmer and see if it gives any error or not. It's also good to scan through the Omron CP1E-N30DT-A manual to see if there's anything you missed out. Remember, the devil is often in the details.
Given your setup, it sounds like there might be an issue related to the way you're setting your pulse conditions on the PLC system. For instance, confirm whether you're correctly using the leading edge or lagging edge for pulse capturing. Also, you might want to check if you’re using a correct pulse rate suitable for your driver. Another potential issue could be related to noise interference affecting the signal transmission from the PLC to the stepper motor driver. In this case, shielded twisted pair wires might help to reduce the noise. Lastly, you could also try testing the voltage level on the PUL- and DIR- outputs when they're active to ensure they are correctly producing a 24V signal.
It sounds like you've done a thorough job of checking the wiring and ensuring everything is powered correctly, but this does sound like a signal issue. It's possible that the PLC isn't sending out the right kind of pulses for your driver. If the PLC is pulse output is compatible with the input of the stepper driver, it should work. However, sometimes the communication between them can drop due to noise or voltage inconsistencies. I'd recommend checking the pulse output signal from the PLC with an oscilloscope if possible, it may help you to confirm whether your PLC output is functioning correctly. Also, ensure your PLC programming is set correctly for the stepper motor you are using. If nothing works, it may be necessary to try a different PLC model or stepper driver.
I would first suggest verifying that both stepper motor driver and PLC are configured correctly and are compatible. Also, ensure the actual wiring connections match the planned configuration. Flickering or continuous lights could indicate that the outputs are stuck in an active mode, which might explain why the pulses aren't being registered. Additionally, verify the 24V power source for faults, as a fluctuating power supply could lead to issues. Last but least, check your 2k resistor - if it's not adequately dropping voltage to the desired level, the system may not work as intended. For specific instructions and personalized guidance, I recommend reaching out to Omron support, especially if the PLC is in warranty. They generally provide helpful and quick assistance.
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Answer: Answer: The issue could be related to the wiring configuration or the programming of the PLS2 instruction. Double-check the wiring connections and ensure that the PLS2 instruction is correctly programmed to generate the required pulses.
Answer: Answer: You can start by verifying the wiring connections between the PLC outputs (100.00 and 100.02) and the stepper motor driver (PUL- and DIR-). Ensure that the connections are secure and correct, and check if the voltage levels are suitable for the driver's input requirements.
Answer: Answer: The problem might be related to the compatibility of the PLC output signals with the stepper motor driver's input requirements. Check the voltage levels, wiring polarity, and signal types to ensure they match the specifications of both the PLC and the stepper motor driver.
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