If your local system has been rebanded the original version of the Pro 92 cannot be programmed for it because the firmware cannot be upgraded. Two later versions (they look identical but have a different firmware protocol) can be upgraded with a download. If you read the RR Wiki for Pro 92 it's explained in the rebanding section and you can find out how to tell what version you have.
I don't think it has been rebanded and from what I read it's the opposite the original can be upgraded and the new cant, but I really don't think portland has been rebanded. Maybe someone can shed some light on that.
the pro 92 will work with Portland Public Safety Radio System , BUT you will have to program all the freqs listed in the Simulcast Backbone . This scanner IT NOT a control channel only scanner , need em all.