I am currently working on a project involving linear motion control using a ballscrew shaft driven by a stepper motor and controlled by a PLC system. The PLC model I am using is the Omron CP1E-N30DT-A. The stepper motor in use is a Nema 34. The main objective is to enable the stepper motor to move in both clockwise and anti-clockwise directions. However, I am encountering an issue where the stepper motor driver does not seem to be receiving any pulses from the PLC. I have utilized the PLS2 instruction to generate and control the pulses. Despite observing the indicator lights on in outputs 100.00 and 100.02, which I have designated for this purpose, the driver does not register any pulse signals. I have connected the PUL- to 100.00 and DIR- to 100.02, with PUL+ and DIR+ linked to the positive 24V through a 2k resistor. The common terminals for 100.00, 100.01, and 100.02 are all connected to the negative 24V. Any advice or assistance on this matter would be greatly appreciated.
Have you verified that your PWM driver module sources at 24v? Many of the ones I've come across typically operate at 5v and sink.
I believe the PLC output is sinking, which is why the common ground is negative. This can have an impact on the overall circuit performance.
Certainly! The power is supplied to a pin on the drive module, with the PLC's common being at 0V. Depending on the type of drive you're using, there may be issues to watch out for. For example, I encountered a problem with a PWM drive module where the input is 5V sinking, while the PLC is normally 24V sinking. It sometimes worked and sometimes didn't, as the sinking outputs were only pulling down to around 2.4V instead of 0V. A typical connection involves the inputs being pulled down. It's also advisable to reduce the PWM to a slow, long pulse to accurately measure the pulse coming out of the PLC.
Upon reviewing the PLC's pulse output, I noticed that the voltage remains steady at 24V when the output is off. However, when the output pulse is activated, the voltage drops to 12V and remains steady. Ideally, the voltage should fluctuate between 24V and close to 0V. This issue seems to be the underlying cause of the problem, but I am unsure of how to resolve it.
PLC transistor outputs require a higher load capacity for optimal performance. To address this issue, a resistor was added to the power supply of the PWM card (for the inputs) and another resistor was connected from the PLC output to ground to provide additional load. This modification successfully resolved the issue, as PWM card inputs have high impedance and minimal current draw.
Hey, your setup sounds pretty solid, but here's one thing you might want to look into. It's possible your issue might lie with the current across the 2k resistor being too low for the driver to detect it. This could explain the lack of pulse signals. You could test this hypothesis by adjusting the resistor value to increase the current, but be mindful not to exceed the driver’s permissible input range. Alternatively, check the correlation between the PLC's output pulse characteristics and the driver's input pulse sensitivity. Remember, the finer details in the communication between these two components are crucial for such systems to work. Hope this helps!
It seems like you've taken meticulous steps in your assembly, kudos to you! I wonder though, if the issue might be with the voltage drop across your resistor. The stepper driver could be failing to register the signals because the voltage is not high enough, given that PLC outputs tend to be 'sourcing'. My suggestion would be to try and connect the PUL+ and DIR+ directly to the positive 24V without a resistor. Of course be cautious doing this. Alternatively check the voltage at the PUL- and DIR- while the PLC is outputting to ensure it's at correct levels. Also, be sure to check the wiring again. It's surprising how often overlooked wiring errors can be the culprit.
It sounds like you've covered all bases with your setup, but here are two things that could be causing the issue. One possibility could be that the voltage difference between PLC output and stepper motor driver input is not sufficient. Try to verify the output pulse voltage from the PLC; it should match that of the stepper driver's input tolerance as Nema 34 has higher voltage requirements. Secondly, you may want to double-check your wiring configuration, particularly your Terminal Block settings. Sometimes, a little wiring oversight can make things go haywire. It could be that the PLC’s output terminals are not properly grounded or that there's weak contact between the connectors. Make sure all those connections are secure. Just a few suggestions from my side, but you also might want to refer to the Omron PLC and stepper driver's manual for more detailed troubleshooting guides. Good luck!
From your explanation, it seems like you've set up your PLC system and stepper motor correctly. However, if the stepper motor driver isn't receiving pulses from the PLC, it might be an issue with either the PLC outputs, the stepper motor driver input, or the connection between the two. I'd suggest you start by validating the output from the PLC's side. Use an oscilloscope to confirm that it's generating the expected pulse duty cycle and amplitude. Also, double-check if your PLC model (Omron CP1E-N30DT-A) requires any specific configuration for pulse output. On the stepper motor driver side, ensure that it's capable of receiving the pulse rate outputted by the PLC. Lastly, inspect your circuit connections to ascertain if the signal is rightly transmitted from the PLC to the driver.
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Answer: - This issue could be due to incorrect wiring connections or configuration settings in the PLC program. Double-check the wiring connections and ensure that the PLS2 instruction is set up correctly to generate the pulses.
Answer: - To troubleshoot pulse output problems, verify the wiring connections between the PLC outputs and the stepper motor driver. Check the programming logic for any errors in generating the pulses. You may also want to confirm the compatibility between the PLC model (CP1E-N30DT-A) and the stepper motor driver.
Answer: - The lack of pulse signals reaching the stepper motor driver could indicate issues with the wiring, programming errors, or compatibility problems between the PLC and the driver. Ensure that the PUL- and DIR- connections are correctly linked to the PLC outputs and that the driver is configured to receive pulses in the correct format.
Answer: - When setting up the Omron PLC outputs for controlling a stepper motor, make sure to assign the correct output channels for generating pulses (PUL+) and direction signals (DIR+). Check the wiring connections and verify that the PLC program
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