If you've installed CUPS and are getting filter errors, it may be that the filter was compiled for the wrong system. For your convenience, these are the compiled filters for Hoin POS rastertopos (80mm paper) and ratertopos58 (58mm paper). The 32 bit folder is the one which came from the factory, and the 64 bit folder are the ones I recompiled so it'll work on 64 bit systems like Raspberry Pi 3. The source is also in this repository, so you could try building it yourself instead.