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