EPOS4 / IDX: Étapes d'action en cas d'échec de la connexion USB

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Topic:

• What can be checked in case an EPOS4 or IDX does not connect to EPOS Studio by USB?

Solution:

Scope of information:

All information is valid for EPOS4 and IDX. There is just EPOS4 mentioned in the following but this also includes IDX (which are all based on EPOS4 technology). The older EPOS2 uses different USB drivers instead. All hints about "Human Interfaces Devices" and USB driver just apply for EPOS4 and IDX but not for the EPOS2.

Precondition:

If an USB connection cannot be established, it has to be checked initially if the USB cable, an USB hub, or the USB port of the PC might be possible root causes. It also has to be checked if the EPOS4 is alive and powered on. Please take care of the following preconditions:

Important:

• Just plug / unplug the USB cable in EPOS4 power-off state!
  Please note the corresponding remark present in any EPOS4 "Hardware Reference":
  
• If the EPOS4 is powered off, it will not(!) be recognized by the USB driver and not by "EPOS Studio".
  Finally the EPOS4 has to be connected by USB and powered on to establish USB communication.

Recommendations:

• Please take care that an up-to-date EPOS Studio version is installed. The required "EPOS Setup" package is available within the "Downloads" section of each EPOS4 product website and the  "http://epos.maxongroup.com".
• Please check that at least one EPOS4 LED is on or blinking when the USB cable is disconnected and the EPOS4 is powered on. A LED in "on" or "blinking" state indicates that the internal logic and processor is probably o.k.
• Please just use USB cables with a maximum length of 3 m and just plug / unplug the USB cable in power-off(!) state.
• Do not(!!) put the USB cable in parallel to unshielded power cables of motors, relays or other inductive or switching loads. Do not put the USB cable in the same wire harness and cable channels like power cables.
• Please avoid USB hubs (at least during testing), i.e. connect the EPOS4 directly to an USB port of the PC.
• Please check the functionality of your PC's USB port with some other USB device too. This should clarify if the PC's USB is damaged and has been the root cause of the failing communication. Even use another PC for testing in addition. If the PC / EPOS4 communication works by another PC, the problem might be caused by one's PC's hardware, Windows installation, or USB assignment (USB0, USB1, ...).

If all of these mentioned points are o.k. but the USB communication still fails, please check if the EPOS4 is detected by Windows "Device Manager" and the USB drivers.

EPOS4: USB Driver

Technical background:

The EPOS4 uses Windows so-called "Human Interface Device" (HID) driver for USB data exchange.
Remark:
The EPOS2 (instead of an EPOS4) demands for specific USB drivers (of FTDI). Finally this means that the drivers in use by EPOS2 and EPOS4 are different and do not have the same representaton by Windows device manager. The EPOS4 uses Windows own USB driver directly.

Checking the driver using Windows "Device Manager":

The question if the EPOS4 is detected by the USB port can be answered by checking the "Human Interface Device" branch of the Device Manager.

Line of action:
Please switch the EPOS4 on / off like stated by the different test steps but do not(!!) plug / unplug the USB cable in power-on state!

1. Connect the EPOS4 by USB, but not(!) switch EPOS4 power on.
   
   
2. Open Windows "Device Manager" and check the "Interface Devices" branch
   ​
   -> Count how many entries are present within the "Human Interface Device" branch.
   
   
3. Switch EPOS4 on
   => The list of "Human Interface Devices" is updates, i.e. there is one additional entry like "HID-compliant device" or "USB Input Device" appearing after the EPOS4 has been switched on and it is detected by the Windows drivers. The new entry might be somewhere in the list, i.e. it is typically not appended at its end.
   
   -> Count how many entries are present within the "Human Interface Device" branch now.
   => There must be one entry more present after the EPOS4 has been switched on and EPOS4's USB works fine.
   ​
4. Right-click on the additional entry (or check some of these) and select "Properties" of the pop-up menu. Select the property "Hardware-IDs" by the "Details" tab. The EPOS4 device can be identified by maxon's manufacturer hardware virtual ID "HID\VID_24E7..."
   
   
   
5. Additional test: Switch EPOS4 off again
   => The EPOS4 entry disappears in the list.

The test steps described above state clearly if the "Device Manager" and Windows USB drivers have been able to detect the EPOS4 connected to the PC's USB port.

If no HID entry is created at EPOS4 power-on, there is possibly the USB port of the EPOS4 or PC damaged. If you are not sure about it, please return the EPOS4 for further investigation and testing to your local maoxn representative (or the global Service Center located at maxon's headquarter in Switzerland).

If there is an HID entry (triggered by EPOS4 power-on) present, please process the following steps by EPOS Studio:

• Start EPOS Studio.
  
• Delete the complete "USB" main branch of the Communication Tree.
  
  
  
• Open the menu "Extras / Device Catalog" and add "USB" (-> "Add Communication") again:
  ​
  
  
• Right-click on the top-level general "USB" (not USB0, ...) and select "Scanning Devices":
  ​
  
  
• ​"Start Scanning"
  ​
  => The EPOS4 (in power-on state) is detected and assigned to its USB port (USB0, USB1, ...).
  
  
• You can connect to the EPOS4 now.
  ​
  =>
  

Cross reference:

• Erreurs de communication USB sporadiques
• Conseils en cas de problèmes de mise à jour USB ou firmware
• EPOS2 / EPOS4: Messages d'erreur de trame de données série (USB / RS232)

Next actions?

If all for these hints do not succeed or might be not fully clear, please contact your local maxon sales and support team and discuss next recommended action steps.