Thank you Anne. I thick I would know more about the usage of submaster.
The fader can be selected as submaster, playback or grandmaster at fader configuration page. If a fader is operated as a submaster with opening up the virtual fader page by typing the "Alt 1" on external keyboard. For example, Sub 1 contains channel 1 at full ,however the "Assert" and "Bump" buttons of Sub 1 virtual fader seem not working fine while I was clicking each of them. Apart from that the bump button of physical Sub 1 fader can bump up the "intensity of Channel 1 and "what is the function of second buttons which located at the top of bump button?" Does it work as a solo?
How to implement this second bottons when assigned fader as a submaster?
Thanks
Kelvin Leung