Gree XK86 Owner's Manual page 8

 System mode priority defaults to master-slave mode, and only certain units have
other system mode priorities.
 When two wired controllers control one (or more) indoor unit(s), the address of
wired controller should be different.
 Functions with "*" are optional for indoor units. If a function is not included in an
indoor unit, wired controller can't set the function, or setting of this function is
invalid to the indoor unit.
Wired Controller (XK86 and XE76-33/H)
3