<p>Seems like you are looking in the wrong place. I am pretty sure that this unnamed software of yours is what sends a homing command when opening connection. Best way to test is just connect to it from another control software like Pronterface, Arduino IDE or any USB serial software and it will not do that because they don't tell the printer to home Z.</p>

CC BY-SA 4.0
2022-12-23T23:36:57.527Z
Hello, Gerge! Glad to have you here. As you mentioned, without additional details it is difficult to offer a proper solution. After gaining enough reputation, you will be able to post comments that can ask for clarification from the original poster. I would also recommend that you take the [tour] to better understand how the site works.
agarza
CC BY-SA 4.0
2022-12-23T23:09:44.323Z
2022-12-24T16:09:25.340Z
2022-12-24T16:09:25.340Z
Gerge
<p>We have the problem that our machine automatically performs a Z-homing when our software connects to the Arduino, but only the Z-axis. We would like to disable it, but could not find the line in Marlin to do it.
Any idea?</p>
<hr />
<p>The software we developed is called <a href="https://github.com/OfficeChromatography/OC-Manager3" rel="nofollow noreferrer">OC-Manager3</a> and the machine is the <a href="https://github.com/OfficeChromatography/OCLab3" rel="nofollow noreferrer">OCLab3</a> which is working like a 3D printer but doing different jobs of analytical chemistry.</p>
<p>However, if we serially connect our Raspberry Pi either from Thonny or Visual Studio to the Arduino (booting the Arduino), the same Z-homing occurred. Thus, it is not related to our software but obviously to Marlin.</p>

CC BY-SA 4.0
2022-12-23T13:39:40.957Z
Maybe share which machine it is and what firmware version? And what is "our" software? Homing on connection is not normal, so this must be induced somehow.
0scar
CC BY-SA 4.0
2022-12-23T14:08:42.993Z
Welcome to 3D Printing! When you get a chance, please take the [tour] to understand how the site works and how it is different than others.
agarza
CC BY-SA 4.0
2022-12-24T16:09:30.227Z
Most probably it is related to your config setup, I see that you have a MAX Z endstop, it is more usual to have a MIN Z endstop, but that shouldn't be the problem. None of my Marlin version exhibits this issue, it must be the configuration causing this.
0scar
<firmware><z-axis>
Automatic Z-homing when connected
OCLab
# Automatic Z-homing when connected

(Asked by: username_0 on 2022-12-23)

We have the problem that our machine automatically performs a Z-homing when our software connects to the Arduino, but only the Z-axis. We would like to disable it, but could not find the line in Marlin to do it.
Any idea?

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The software we developed is called [OC-Manager3](https://github.com/OfficeChromatography/OC-Manager3) and the machine is the [OCLab3](https://github.com/OfficeChromatography/OCLab3) which is working like a 3D printer but doing different jobs of analytical chemistry.

However, if we serially connect our Raspberry Pi either from Thonny or Visual Studio to the Arduino (booting the Arduino), the same Z-homing occurred. Thus, it is not related to our software but obviously to Marlin.

**Tags:** firmware, z-axis
> **Comments:**
> **username_1**: Maybe share which machine it is and what firmware version? And what is "our" software? Homing on connection is not normal, so this must be induced somehow.  
> **username_2**: Welcome to 3D Printing! When you get a chance, please take the [tour] to understand how the site works and how it is different than others.  
> **username_1**: Most probably it is related to your config setup, I see that you have a MAX Z endstop, it is more usual to have a MIN Z endstop, but that shouldn't be the problem. None of my Marlin version exhibits this issue, it must be the configuration causing this.  

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## 1 answers

### Answer by username_3 on 2022-12-23. Score: 0

Seems like you are looking in the wrong place. I am pretty sure that this unnamed software of yours is what sends a homing command when opening connection. Best way to test is just connect to it from another control software like Pronterface, Arduino IDE or any USB serial software and it will not do that because they don't tell the printer to home Z.

> **Comments:**
> **username_2**: Hello, Gerge! Glad to have you here. As you mentioned, without additional details it is difficult to offer a proper solution. After gaining enough reputation, you will be able to post comments that can ask for clarification from the original poster. I would also recommend that you take the [tour] to better understand how the site works.  

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