On your Mac, the Brother ControlCenter software that let's you scan an image from your Brother MFC to your computer is started at boot by launchd. Therefore, it can be restarted from the command line.

For example, here is a list of processes controlled by launchd:

$ launchctl list | grep brother
286	-	[0x0-0x17017].com.brother.ControlCenter
282	-	[0x0-0x16016].com.brother.utility.NETserver
281	-	[0x0-0x15015].com.brother.utility.USBserver
266	-	com.brother.LOGINserver

I found that stopping LOGINserver caused all the other services to restart:

$ launchctl stop com.brother.LOGINserver
$ launchctl list | grep brother
36825	-	[0x0-0x258a588].com.brother.ControlCenter
36824	-	[0x0-0x2589587].com.brother.utility.NETserver
36823	-	[0x0-0x2588586].com.brother.utility.USBserver
36818	-	com.brother.LOGINserver

Good luck!