fixed get_heartbeat
fixed get_heartbeat

NMGRL/pychron,NMGRL/pychron,USGSDenverPychron/pychron,UManPychron/pychron,NMGRL/pychron,UManPychron/pychron,UManPychron/pychron,NMGRL/pychron,USGSDenverPychron/pychron,USGSDenverPychron/pychron,UManPychron/pychron,USGSDenverPychron/pychron