I'm having several issues on the ZQ520 only.
Whenever I checked the printer status I get an exception: Malformed status response - unable to determine printer status. My first thought was maybe my implementation is wrong so I downloaded the Xamarin Demo to see it works with the demo's implementation. Ran the demo and got the same exception.
Found a work around to the exception error, which is to always return true when checking the status; however, in the demo and on my app using the demo's formatted string, the ZQ520 prints the incorrect format (correct format on ZD410). Using my formatted string it prints nothing to the ZQ520 (prints on ZD410) even though the following statement is run:
Problem with ZQ520
1) without the workaround I received "unable to determine printer status" exception
2) with workaround it prints incorrect format
3) using my formatted string it prints nothing.
My sample formatted string:
",45^ADN,18,10^FDSome Label: " + "AAA" + "^FS" ... "^XZ";