COGNEX DMR-8700DQ-USB Barcode Scanner Not Connecting

I have been unsuccessful getting a COGNEX DMR-8700DQ-USB Barcode Scanner to connect as a custom barcode scanner in Tulip Player.

I was able to find the VID/PID information in Device Manager, and tried entering it with and without the “0x” prefix, and the device doesn’t connect:


When I hit save, I see a message flash in red down by the buttons saying
“Error saving custom barcode scanners”
and the three fields for the new barcode scanner details disappear.

The device is definitely connected, as it can output as a keyboard wedge, I just cant get it to connect to Tulip such that it will register as barcode scanner output to initiate device triggers.

Any and all suggestions appreciated.

On a whim I tried connecting on a new laptop with a fresh install of Tulip Player and it worked.

Went back to my laptop, and still having issues there. I can’t even remove one of my existing connected custom barcode scanners, nor can I replace its data with the new scanner data.

Loathe though I am to do it, I might uninstall Player from my computer and start over…have to redo all my server connections though, which is a pain…

Any alternatives to the aforementioned are welcome!

Hey @jmlowden, looks like you got it working (good!) after some difficulty (not good!). Just adding some 2¢ here -

I had a similar issue happen to me before with a Zebra printer; it had been plugged into PC 1 for a while, and Tulip was having issues connecting to it. However, plugging it into PC 2 it worked just fine.

The issue was that sometime within the printer’s lifetime being plugged into PC1, the PC had installed a driver for it. So, the printer was no longer a generic device, but actually a Printer using the Printer Driver.
PC 2 lacked whatever driver let PC 1 recognize the printer, so it just defaulted to a generic driver.

I have an inkling that might be happening here; I would wonder if sometime, you used a program or installed a package that recognizes the scanner, changing it from a “generic HID” device to something more specific. This suspicion is stronger when, in your screenshot, you see the device is called a USB Composite Device. I normally see them as a HID Compliant Device.

To fix this, I would expect you could either:

  1. Uninstall the device entirely, plug cycle it, and see if it shows up as a HID device in Device Manager
  2. Change the driver being used for this device in Device Manager (Right-Click >> Update Driver >> Browse my Computer >> Pick from list of available drivers, find HID-Compliant Device)

Not a 100% solution, but definitely similar to what stuck me for a while. let me know if this helps.

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The same device VID1447/PID8130 actually shows in multiple categories in Device Manager





I did uninstall and reinstall the device, and attempted to update the driver but it ended up with the same driver/version installed as before.

Here is the log info for the device.
Device USB\VID_1447&PID_8130\1A2320PP376745 was configured.

Driver Name: usb.inf
Class Guid: {36fc9e60-c465-11cf-8056-444553540000}
Driver Date: 06/21/2006
Driver Version: 10.0.19041.4474
Driver Provider: Microsoft
Driver Section: Composite.Dev.NT
Driver Rank: 0xFF2003
Matching Device Id: USB\COMPOSITE
Outranked Drivers:
Device Updated: false
Parent Device: USB\ROOT_HUB30\4&25b7d121&0&0

That brought me back to Tulip Player.

After reconfirming that the same connection error persisted, I tried a “Developer>Clear All Data” without the “Clear global data” checked. This did not resolve the issue.

I then tried the same with the “Clear global data” checked and was able to add back all my scanners, including the new one, and confirmed that it does output to Tulip Player as a barcode scanner device, with all triggers firing!

After going through this excercise, I had a vague recollection that we experienced a related issue back in 2023 having something to do with duplicate barcode scan trigger fires and it was related to having used the same custom barcode scanner device connection with our DEV instance and then later our PROD instance after go-live (both are private-hosted).

I don’t recall the specific resolution steps for this, but I think it might have been the same as what I did above. Before I invoked the “Clear global data” nuclear option, Tulip player did “remember” all the instances/servers I was connected to, evidenced by listing them on the login screen (but they did not show up in the “Developer>Change Server” list).

Does adding custom barcode scanners work from an instance/server level or just at the Tulip Player level where it is installed on a specific PC?

My experience suggests the former.

It would be good if there was a fix to prevent whatever precipitated this issue, or at least a less tedious way to remediate (I need to redo all my display device connections for all the servers I was using that were lost with the global clear).