<p>The <a href="https://www.simplify3d.com/support/faq/#faq-4630" rel="nofollow noreferrer">Simplify3D support site</a> mentions to disable the "wait for startup command" option in the firmware configuration for S3D.</p>

<p>This allows me to make a rudimentary connection to control the printer, however e.g. during the bed levelling wizard of S3D, the connection still breaks off.</p>

<p>It works reliably with Octoprint. I'll consider that good enough.</p>

CC BY-SA 3.0
2017-02-01T06:12:59.283Z
2017-04-21T17:10:24.293Z
2017-04-21T17:10:24.293Z
brandstaetter
<p>If you are using a USB 3 port to connect the printer to your PC, try connecting via a USB 2 hub.  </p>

<p>My Vector 3 will not work on a USB 3 port, only on a USB 2 or lower.  The device correctly mounts and presents but serial communication fails.  One of my laptops only has USB 3 ports on it, so to work around the limitation I connect via a cheap USB 2 hub. </p>

<p>I have heard that many 3D printers use a similar USB to UART / serial connector chip and that they suffer from similar limitations as a result.  </p>

CC BY-SA 3.0
2017-02-01T15:23:25.077Z
already tried that, did not change anything :(
brandstaetter
CC BY-SA 3.0
2017-02-01T16:18:11.260Z
The cheapest, and common, USB to Serial IC (i.e. an FTDI clone) in use, seems to be the CH340g
Greenonline
CC BY-SA 3.0
2017-03-12T13:00:40.960Z
@Greenonline The CH340 is *not* an FTDI clone. Not every USB to Serial IC needs to be an FTDI clone. The CH340 happens to be an independent design.
Tom van der Zanden
CC BY-SA 3.0
2017-03-12T13:05:56.347Z
@TomvanderZanden - OK, understood. :-) I guess I should have said _substitute_ rather than _clone_.
Greenonline
CC BY-SA 3.0
2017-02-01T14:02:10.757Z
2017-02-01T14:02:10.757Z
TafT
<p>Try changing your port in the control menu. By default, mine is set to <code>COM 1</code> and I have to change it to <code>COM 3</code>.</p>

CC BY-SA 3.0
2017-05-05T12:07:06.170Z
I get a response from the printer: READ: T:24.44 /0 B:23.33 /0 B@:0 @:0. It just aborts the connection due to some timeouts. Looks like S3D is very strict when it comes to bad connections or slow boards
brandstaetter
CC BY-SA 3.0
2017-05-05T04:48:41.920Z
2017-05-05T22:12:12.350Z
2017-05-05T22:12:12.350Z
3d noob
<p>I have a Tronxy P802M (very similar to the Anet A8, but using a Melzi2.0V5 board) that seems to work fine (I just finished building, and axes movement and the integrated display work) but when I try to connect to the printer from my Simplify3D on Windows 10, I get the following:</p>

<pre><code>[...]
  Connected to machine!
SENT: T0
READ: ok 0
READ: wait
SENT: M105
READ: ok 0
READ: T:24.44 /0 B:23.33 /0 B@:0 @:0
  Connection failed.
</code></pre>

<p>My other printers all connect fine.</p>

CC BY-SA 3.0
2017-01-26T15:10:20.297Z
Try doing this in Simplify3d and see if it works - Go to Tools --> Firmware Configuration and then click the Communication tab. Set the flow control to "Hardware flow control".
tjb1
CC BY-SA 3.0
2017-01-27T08:46:59.633Z
Nope, did not change much, except now the initial connect does not work. I also tried a different USB cable and using a direct USB port as well as suing a USB2 hub...
brandstaetter
CC BY-SA 3.0
2017-01-27T10:28:09.793Z
Operating system?
Sean Houlihane
CC BY-SA 3.0
2017-01-27T14:30:36.003Z
Windows 10 - sorry, forgot the details
brandstaetter
CC BY-SA 3.0
2017-01-27T17:22:51.083Z
Okay have you set the Baud rate? I know thats an issue with slic3r. Can you see the printer under devices?
MakerModder
CC BY-SA 3.0
2017-01-28T20:42:04.650Z
Yes, Baud rate is set the same on both sides (otherwise there are different errors). The COM port shows up under devices.
brandstaetter
CC BY-SA 3.0
2017-01-29T08:49:56.043Z
This is more suited as a comment. Moreover, the fact that he's receiving something legible (like the "T:24.44" line), means the baud rate must be correct.
Tom van der Zanden
<software><electronics><simplify3d><usb><tronxy-p802>
I can not really connect successfully to my printer via USB
brandstaetter
# I can not really connect successfully to my printer via USB

(Asked by: username_0 on 2017-01-26)

I have a Tronxy P802M (very similar to the Anet A8, but using a Melzi2.0V5 board) that seems to work fine (I just finished building, and axes movement and the integrated display work) but when I try to connect to the printer from my Simplify3D on Windows 10, I get the following:

```
[...]
  Connected to machine!
SENT: T0
READ: ok 0
READ: wait
SENT: M105
READ: ok 0
READ: T:24.44 /0 B:23.33 /0 B@:0 @:0
  Connection failed.

```

My other printers all connect fine.

**Tags:** software, electronics, simplify3d, usb, tronxy-p802

> **Comments:**
> **username_1**: Try doing this in Simplify3d and see if it works - Go to Tools --> Firmware Configuration and then click the Communication tab. Set the flow control to "Hardware flow control".  
> **username_0**: Nope, did not change much, except now the initial connect does not work. I also tried a different USB cable and using a direct USB port as well as suing a USB2 hub...  
> **username_2**: Operating system?  
> **username_0**: Windows 10 - sorry, forgot the details  
> **username_3**: Okay have you set the Baud rate? I know thats an issue with slic3r. Can you see the printer under devices?  
> **username_0**: Yes, Baud rate is set the same on both sides (otherwise there are different errors). The COM port shows up under devices.  
> **username_4**: This is more suited as a comment. Moreover, the fact that he's receiving something legible (like the "T:24.44" line), means the baud rate must be correct.  

---

## 3 answers

### Answer by username_0 on 2017-02-01. Score: 1 | Accepted answer

The [Simplify3D support site](https://www.simplify3d.com/support/faq/#faq-4630) mentions to disable the "wait for startup command" option in the firmware configuration for S3D.

This allows me to make a rudimentary connection to control the printer, however e.g. during the bed levelling wizard of S3D, the connection still breaks off.

It works reliably with Octoprint. I'll consider that good enough.


---

### Answer by username_5 on 2017-02-01. Score: 1

If you are using a USB 3 port to connect the printer to your PC, try connecting via a USB 2 hub.

My Vector 3 will not work on a USB 3 port, only on a USB 2 or lower. The device correctly mounts and presents but serial communication fails. One of my laptops only has USB 3 ports on it, so to work around the limitation I connect via a cheap USB 2 hub.

I have heard that many 3D printers use a similar USB to UART / serial connector chip and that they suffer from similar limitations as a result.

> **Comments:**
> **username_0**: already tried that, did not change anything :(  
> **username_6**: The cheapest, and common, USB to Serial IC (i.e. an FTDI clone) in use, seems to be the CH340g  
> **username_4**: @username_6 The CH340 is *not* an FTDI clone. Not every USB to Serial IC needs to be an FTDI clone. The CH340 happens to be an independent design.  
> **username_6**: @username_4 - OK, understood. :-) I guess I should have said _substitute_ rather than _clone_.  

---

### Answer by username_7 on 2017-05-05. Score: -1

Try changing your port in the control menu. By default, mine is set to `COM 1` and I have to change it to `COM 3`.

> **Comments:**
> **username_0**: I get a response from the printer: READ: T:24.44 /0 B:23.33 /0 B@:0 @:0. It just aborts the connection due to some timeouts. Looks like S3D is very strict when it comes to bad connections or slow boards  

---

