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Troubleshooting device connection 2: Software connection to the device


Software connection to the device

  • With the device connected, after verifiying that the OS can detect the device by following the procedure at the top of this document, open the software.
  • If the software shows "Connected" in the title bar, then the software has connected to the device, and you can skip this section. If this does not happen consitently, then stay in this section.

The software detects and connects to the hardware like this:

  1. The software detects the device is connected.
    • On Windows, the Saleae driver must be installed, as the software looks for devices using the Saleae driver.
    • On OSX and Linux, the software searches for USB devices attached that use Saleae USB Vendor and Product IDs. The device's USB VID & PID failed
  2. The software asks the OS for access to the device.
  3. The software downloads the firmware to the device. Before this point, the device is acting as a simple boot loader.
  4. The device resets, and the USB connection disconnects and reconnects.
    • Note: for USB 3.0 devices connected with a USB 3.0 cable to a USB 3.0 port, the device initially connects using USB 2.0, but then re-enumerates over USB 3.0. This is a failure point, and can usually be fixed, at least on Windows, with a driver update. On all platforms, it can also indicate a partial USB cable failure, even if the device is initially detected by the OS when the software is not running.
  5. The software sees that the device has disconnected normally, and then sees a new device is connected, this time running the Saleae firmware.
  6. The software asks the OS again for access to the device.
  7. The software finishes the device configuration (shown in the title bar) and once finished, the title bar will say "completed"

If the OS is able to see the device while the software is not running, as described in the section "PC detection of the device over USB", but the software does not complete the above process and say "connected", then the problem must lie with one of the steps shown above.

Possible problems:

After each test below, you will need to re-run the following procedure:

  1. Close the software if it is open.
  2. Disconnect the device if it is connected.
  3. Connect the device, and verify that the OS sees the device, by following the procedure at the top of this document.
  4. Open the software.

This is called the software connection procedure. It needs to be repeated in order to reset the state of the hardware and the software completely between tests.

Software does not have permissions to access the device.

  • On Windows, the software may show the message "A Logic device was found, but there was a problem connecting to it. Another application may be using it. Please let us know if the issue persists." this message is shown when the OS denies access to the device. In rare cases, this message could be shown from a false positive. If the software still connects after closing the warning, you can continue normally. Normally, this situation can be caused by two reasons. First, another instance of Logic is running and has already taken exclusive control of the device. Second, the software does not have permissions to access the device. This is extreemly rare, even in the presense of enterprise permissions environments. Try running the software as administrator to see if that works. Finally, this message can also be shown if there is a more serious USB issue. If this message is shown at the same time as the mesage "Please unplug, and then reconnect your device" this likely indicates a problem with either the USB cable or the USB host controller.
  • On Linux, if you see the message "A Logic device was found, but there there was a problem connecting to it. This is probably because we don't have permissions to access it. Take a look in the drivers folder for instructions, or run this program as root (i.e. use sudo from the command line). This could also be caused by having multiple instances of the Logic software running. Let us know if you still have any problems." Then this could by caused by one of several reasons. The software does not have permissions to access the device. Either install the udev rules file, or run the software as administrator. If the udev rules file is not working, it might be a compatibility issue with your specifc distro. For very old distros, the keyword "ATTR" might not be supported, and can be replaced with "SYSFS". On Arch, and possibly other distros, try removing the text 'ENV{DEVTYPE}=="usb_device",' from the rules file.
  • On OSX, if more than one instance of the software is running, only one instance will conenct. The other instance will simply stay disconnected, without displaying any error message.
  • Also keep in mind that some Virtual Machines can agressively attach to USB devices as they are connected. This is particularly complicated by the re-enumeration process that the device goes through when first connected to the software. It is possible that even when the logic analyzer is connected to the host, after the initial firmware download, the device re-enumerates and connects to the VM. If you have a VM running, and are having trouble getting the device to connect, please suspend or shut down the VM, and then re-test the connection.

The device fails to re-enumerate after firmware download.

If the device fails to re-enumerate after the firmware download completes, the software will not display any messages. To detect this situation, you need to monitor the device's appearence in device manager or similar before and after the software starts up. Please run the following procedure.

  • follow the procedure in the section "PC detection of the device over USB" and locate the device in device manager (windows), lsusb (linux) or system report (osx).
  • start the software. wait 10 seconds.
  • re-check to see if the device is still listed. On Windows, device manager should automatically refresh in a few seconds if the device state changed. On Linux, re-run lsusb. Is the device still listed? It's name may have changed. Check by VID & PID. On OSX, you must manually refresh system report from the menu, as it does not auto-refresh. Check to see if the device is still listed, missing, or if it's name has changed to "Saleae Logic..."
    • if the device is no longer listed, that means that the firmware download finished, and the device disconnected, but never reconnected. If connected to a USB 3.0 port, it could indicate a USB 3.0 host controller or driver issue. If conencted to a 3.0 port with a 3.0 cable, it could indicate a host controller issue, a host driver issue, or a USB 3.0 cable issue.
  • please re-test on both USB 3.0 and USB 2.0 ports, with USB 3.0 and USB 2.0 cables, if applicable. If the device only works over USB 2.0, then it is most likely a host controller driver issue or a USB cable issue. If the device only works over USB 3.0, or on one or more computers it does not work over USB 2.0, please contact support, as this may be a new issue.
  • Collect more information. Follow the instructions in the article The software has crashed, or I have discovered a bug. titled "Steps to collect additional data" to capture the console output of the software, which may contain more infromation of the issue preventing the device from reconnecting.

The device re-enumerates after firmware download, but an error imidiately occurs

Example: You connect the device, and then start the software. The software then shows the message "Please unplug, and then reconnect your device" and the software says "disconnected" in the title bar. After performing all of the tests above, including testing on multiple PCs, on different types of USB ports, with multiple cables, please contact support.

The device is able to connect some times, but it either randomly disconnects, or only successfully conencts some of the time

This could indicate a bad USB cable, a problem with the logic analyzer, a ground loop problem, or an issue with the host controller or host controller driver. If the logic analyzer is connected to a device under test, disconnect it. This will rule out the posibility of common mode ground current interfering with the device. More info here: What should I do to avoid accidental damage to the device?

The device successfully connects to the software, but there are capture problems

See this guide: The device is not successfully capturing data consistently

trello ID: 568ef458075c384cd36ac46d
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