Well I'm not sure if it an application that you are able to change the code-base for or not, but I'm almost fairly certain this would have to be something done on the web page / web-view that you're using.

If its a WebView inside an app you can do the following:
- (Android / Xamarin.Android) android - Disable SoftKeyboard inside a WebView - Stack Overflow

Since the only code you need to change is in the UI Layout, this SO post covers both Android and Xamarin.Android.

Like I said though, I'm not sure you can disable it through just a normal settings change although I could be wrong.

I'm trying to reproduce your issue, but using the DWDemo application the keyboard does not auto show on TC70x. What Android App are you trying to scan data into.

If this is an application you're designing:
- In the OnCreate / OnStart Activity lifecycle methods insert this:
    - (Xamarin.Android) Window.SetSoftInputMode(SoftInput.StateAlwaysHidden);
    - (Android) Close/hide the Android Soft Keyboard - Stack Overflow

Android takes a little bit more effort and I've included a link to a(n) SO post that covers it very well.

*** Be aware StateAlwaysHidden is misleading it's more like IgnoreInitialAutoFocus event lol