same wheel to increase and decrease parametre?

You should take a look at the Show Control chapter in the Eos Manual as it is fairly extensive on describing what Eos can receive in terms of OSC: https://www.etcconnect.com/WebDocs/Controls/EosFamilyOnlineHelp/en-us/Default.htm#32_Show_Control/08_Open_Sound_Control_(OSC)/Supported_OSC_Input/OSC_Wheel.htm?TocPath=Show%2520Control%257COpen%2520Sound%2520Control%2520(OSC)%2520%257CSupported%2520OSC%2520Input%2520%257C_____4

If you make the Lower OSC Value -1 you should be able to decrease the value.

i keep on looking to that, to the forum and to the diag tab but it's not easy to get for my osc novice eyes.

i already tried to change lower for -1 higher for 0, didn't make no difference. if i change for -1/1, i reach full at 50% of fader fade. tried many things from the webdoc who didn't work and can't say where i'm wrong, what possibly fit nanokontrol or not, what i misconfigured. I'd love to see how a full osc eos working is config to see how every step is incremented, didn't succeed for now to read deep in some github file.

i keep on looking to that, to the forum and to the diag tab but it's not easy to get for my osc novice eyes.

i already tried to change lower for -1 higher for 0, didn't make no difference. if i change for -1/1, i reach full at 50% of fader fade. tried many things from the webdoc who didn't work and can't say where i'm wrong, what possibly fit nanokontrol or not, what i misconfigured. I'd love to see how a full osc eos working is config to see how every step is incremented, didn't succeed for now to read deep in some github file.

One of the best tools for understanding OSC in & out of Eos is OSC Widgets: https://github.com/etclabs/oscwidgets

It's a great unofficial tool provided by some ETC developers. You can use it to structure OSC messages and see how they interact with Eos. Many of the OSC messages in the documentation can be copied and pasted into OSCWidgets.

Part of the problem with this is not all OSC messages are structured the same, and other softwares have limitations. Have you confirmed that the software you're transmitting with can and is sending a value that's -1?

 Sammy also has a series of blog posts that explain a lot about OSC, if you haven't checked them out they're a good primer: https://blog.etcconnect.com/2017/08/exploring-the-network-osc-part-i

@skt : as 0/-1 work,  i guess we can use -1. the app is Midi to Osc COnverter, found on github.

thanks, just have to work now