Split/Dual/Layers on A-800pro & Logic Express

Hello, At the beginning, sorry for my english, I'm not native english speaker ;) I've bought A-800pro several months ago. It's fine for me, even though I can't set up many things, but on the other hand, I don't need to do that. I'm used to stage pianos, such us Roland RD-600, where I choose sound and that's all, everything works without playing with midi settings etc. But I needed something lightweight, to connect to my Mac and take with me on smaller gigs, and because of that I've decided to buy A-800pro. But suddenly I found huge problem. I can't set layers on it. On my Roland RD-600 i used to click "Upper", choose sound, then click "Lower" and choose sound for lower part, and then, if both buttons were pushed together then it was Dual, and when I clicked "Split" they were splitted, and that was all. Now I use Logic Express, and to choose a sound I have to create New Software Track, eg. Electric Piano, and it works fine. Then, when I create second Software Track, eg. Pad, the sound of that pad comes only when I click with my mouse on that track. Manual for A-800pro says that to set upper/lower parts of keyboard you have to simply press "Upper" button, use arrows to "Pgm change" and change the sound with the value knob. Then, after setting both upper and lower parts, normally after pushing "Dual" button they should be heared together, while when in "Split"mode, they should be splitted. But when I'm changing the "Value" parameter whith the knob, nothing happens, I still hear the sound selected in Logic, eg. Electric Piano. On A-800pro Editor program on my computer, I set up in the Keyboard Set Windows, due to manual, the upper part to be sent on 1 Midi channel, and lower at 2. Nothing happend. I also tried to do that in Logic. In the inspector menu there's an option "Midi channel". So I tried to do something like that: I created a new software track, choose electric piano, then set midi channel parameter as 1. Then create second track for pad, and on that track choose midi channel 2. Then on A-800pro I pushed "Upper" button and set "pgm change" and "Midi channel" parameters to 1, and after pushing "Lower" button i set both of this parameters to 2. Nothing happened, I still have to choose what I want to hear in Logic by clicking on the one from prepared tracks. What can I do? Can anyone help me? I think this is probably very simple, and maybe I'm doing very small and stupid mistake but after spending hours and hours on lookin for that on the internet I decided to ask for help. Greetings from Poland and thanks for Your help :)