Item Frame Detector

/entitydata @e[r=1] {}

BELOW COMMAND IS ONLY INDICATIVE, HERE FOR SHOWING STRUCTURE. MANY TAGS OF YOURS MAY BE DIFFERENT

/testfor @e[type=ItemFrame,x=-650,y=57,z=321] {Motion:[0:0.0d,1:0.0d,2:0.0d],Facing:0b,UUIDLeast:-4936593859520216930L,ItemRotation:0b,Invulnerable:0b,Air:300s,OnGround:0b,Dimension:0,PortalCooldown:0,Rotation:[0:0.0f,1:0.0f],FallDistance:0.0f,Item:{id:"minecraft:comparator",Count:1b,Damage:0s},ItemDropChance:1.0f,UUIDMost:-5558676685809041275L,Pos:[0:-649.5d,1:57.5d,2:321.03125d],Fire:0s,TileY:57,TileX:-650,TileZ:321}