Hi All,

I am very new to the Logo! and recently posted about using it for some stepper motor drives. For this program I need to turn on the stepper motors for 180 degrees then stop the motor for 20 seconds before it repeats the process. I had originally tried using this through counting the pulses through the PWM but could not find a way to only send 100 pulses so I have tried to pivot to using an Automation Direct normally closed proximity sensor (DW-AS-614-M18-002) and SureStep Motor and Driver (STP-MTRAC-34156andSTP-DRVAC-24025).

I have gotten the Logo! to turn on and off the motors using the C1 a pulse relay and a PWM to Q1 (Which can be seen in the 2 modified versions, but it will only let me upload 1 image). I tried modifying this program in 2 ways (The C2 and I2 should be C1 and I1 it just shows my two modifications in one image) to get the sensor to act as a trigger to turn off the motor, but neither of these methods worked.

I was hoping someone could help me as I believe it is an issue with how I have the sensor setup. Whenever the sensor is triggered, the lights on the sensor housing are acting as they should (off when metal is present) but I am not sure how to tell if the Logo! is receiving the signal from the sensor to turn off the motor.

I may also have a programming error which could be easily fixed and I apologize for the simple questions. I am very new to electrical work in any capacity as my background is completely mechanical.

Thank you for all your help

ixo65

You use the PWM block without knowing of the function of the block ...

 Thank you for that. I am just going based off of the research I have done on how to do this.

Maybe you would be willing to actually help?

ixo65

First, please check whether you have wired the proximity switch correctly.

The brown wire (1) must be connected to 24VDC.
The blue wire (3) must be connected to 0VDC (or M of the LOGO!).
The black wire (4) must be connected to the input of the LOGO!, e.g. with I1.

There are various options to check that the LOGO! recognizes that I1 is assigned a 1 signal.

1.) The display of the digital inputs in the start menu.
Go to the start screen (Date + time). Then press 1x the cursor right button.

If I1 has 1 signal, then the number 1 in the top row is marked with a black rectangle.

2.) Use the Online Test of the software LSC.
Start the LSC and run the program. Click on the "Online Test" button.

If I1 has 1 signal then is I1 in the diagram red marked.

 I do have the proximity switch wired correctly. However whenever the sensor is sensing, the light on the housing turns off but the 1 is not being shown with a black rectangle around it. How would I go about fixing this?

ixo65

It may be that the LOGO! input alone is not enough load for the sensor (input impedance too high).
Wire for test an additional 10 kΩ resistor parallel to the LOGO! input.

 Thank you for all of your help I got the wiring sorted and now am able to use the proximity to trigger the motors to switch. 

I was now wondering if you knew of anyway of sending the pulses faster than the .01s available on the PWM block. With the PWM block, I am able to get a full rotation in 2 seconds (200 pulses at .01s), but according to the manual it says that the maximum switching rate is dependent on the program cycle time. My goal would be to double the output signal speed so I could do a 1 second revolution.

I was wondering if you would be able to help me with that. I have tried finding in other forum posts how people have accomplished this but cannot find anything on it. 

ixo65

Here a example for the highest speed.

 Is there any possibility of using the stopwatch? I know that it can read in milliseconds, but am having a hard time figuring out how I could potentially use that to create shorter pulses.