The players on the inside move to different players on the outside to either receive or pass to that player. Calling for ball is a good thing. I also recommend that the player put out an open hand to the foot side he prefers the pass. This is also a signal to keep the ball on the carpet. The outside players should constantly be bouncing and ready to play at the first show from the inside player.
Eye contact is important.
The checking player may have to stop his run as the other player is beginning to pass. That way, the checking player can adjust to the direction the ball is played. The two inside players work a 3-man combo with the outside player. Or the second inside player acts as a defender marking the other inside player as he checks to ball. Around the Barn Passing I had seen this basic setup before and didn't think much about it.