Minor Things

For example, lets say the San Francisco giants called up a catcher from the minor leagues. He plays for a month, then they send him back down to the minor leagues. How much does he get payed for that month that he played in the Major leagues.

Players get called up from the minor leagues and sent back down just like in baseball. However, some of the minor leagues in hockey are actually considered semi-professional leagues. Were leagues such as the AHL and ECHL established independently of the NHL and they have some sort of transfer agreement for players? How exactly does it work?