ZQ520 not printing images in CPCL mode

We have a large amount of existing CPCL code used in iOS applications that works properly when printing to the rw420 printer.

 

This same code also works with the ZQ520 except for the images. They do not print using this command even though the printer shows they are in permanent memory. This is the command used to print that also works on the rw420.

 

PCX 11 8 !<ERSLOGO.PCX

 

I tried a number of workarounds found on this blog and the web and nothing works except using this ZPL code to print the image:

 

^XA^FO0,0^IME:ERSLOGO.GRF^XZ

 

I have tried the following:

 

remove the extension

 

changed the extension to GRF

 

followed instructions in this knowledge based article to upload as PCX: https://km.zebra.com/resources/sites/ZEBRA/content/live/SOLUTIONS/8000/SO8519/en_US/Command_Line_Converting_PCX_Files.pd…

 

nothing worked. in fact, the above didn't work properly in ZPL either, it printed something but it was not the image we expected and seemed that the colors were inverted.

 

Any help with this is very appreciated. We really don't want to rewrite all the CPCL code into ZPL just to print images. This seems to be a bug in the ZQ520 firmware as it should be backward compatible.