A reduced-pressure system comprising: a dressing ; a regulator comprising: a supply chamber adapted to be fluidly coupled to the dressing , a charging chamber fluidly coupled to the supply chamber through a port, and a regulator valve coupled to the charging chamber and operable to reciprocate to control fluid communication through the port based on a differential between an ambient pressure and a therapy pressure; and a feedback interface fluidly coupled to the regulator and adapted to signal an operating state of the reduced-pressure system in response to a pressure received through the fluid coupling between the feedback interface and the regulator, characterised in that the feedback interface comprises a visual feedback interface, wherein: the feedback interface comprises a window , a first indicator ring , and a second indicator ring ; the first indicator ring is configured to be visible through the window at a first pressure; and the second indicator ring is configured to be visible through the window at a second pressure, wherein the feedback interface further comprises: a housing comprising a chamber disposed between an end wall and an open end, and the window is proximate to the open end; a diaphragm disposed in the chamber, the diaphragm having a peripheral portion coupled to the housing; a stem coupled to the diaphragm and having a portion passing through the diaphragm ; a cap coupled to an end of the stem proximate to the open end of the housing, the cap having the first indicator ring and the second indicator ring; and a biasing member coupled between the diaphragm and the end wall, wherein the biasing member is adapted to exert a force urging the diaphragm toward the open end. a dressing ; a regulator comprising: a supply chamber adapted to be fluidly coupled to the dressing , a charging chamber fluidly coupled to the supply chamber through a port, and a supply chamber adapted to be fluidly coupled to the dressing , a charging chamber fluidly coupled to the supply chamber through a port, and a regulator valve coupled to the charging chamber and operable to reciprocate to control fluid communication through the port based on a differential between an ambient pressure and a therapy pressure; and a feedback interface fluidly coupled to the regulator and adapted to signal an operating state of the reduced-pressure system in response to a pressure received through the fluid coupling between the feedback interface and the regulator, characterised in that the feedback interface comprises a visual feedback interface, wherein: the feedback interface comprises a window , a first indicator ring , and a second indicator ring ; the first indicator ring is configured to be visible through the window at a first pressure; and the second indicator ring is configured to be visible through the window at a second pressure, wherein the feedback interface further comprises: a housing comprising a chamber disposed between an end wall and an open end, and the window is proximate to the open end; a diaphragm disposed in the chamber, the diaphragm having a peripheral portion coupled to the housing; a stem coupled to the diaphragm and having a portion passing through the diaphragm ; a cap coupled to an end of the stem proximate to the open end of the housing, the cap having the first indicator ring and the second indicator ring; and a biasing member coupled between the diaphragm and the end wall, wherein the biasing member is adapted to exert a force urging the diaphragm toward the open end. the feedback interface comprises a window , a first indicator ring , and a second indicator ring ; the first indicator ring is configured to be visible through the window at a first pressure; and the second indicator ring is configured to be visible through the window at a second pressure, wherein the feedback <EOS>