NRPE

How do i configure for NRPE.
Nagios now tells me “UNKNOWN: No health status line found”

But when i run the command like:
/usr/local/nagios/libexec/check_smart -i ata -d /dev/sda1
I get:
OK: no SMART errors detected|Raw_Read_Error_Rate=0 Spin_Up_Time=5258 Start_Stop_Count=58 Reallocated_Sector_Ct=0 Seek_Error_Rate=0 Power_On_Hours=31969 Spin_Retry_Count=0 Calibration_Retry_Count=0 Power_Cycle_Count=58 Temperature_Celsius=28 Reallocated_Event_Count=0 Current_Pending_Sector=0 Offline_Uncorrectable=0 UDMA_CRC_Error_Count=17 Multi_Zone_Error_Rate=0

NRPE config:
command[check_smart]=/usr/local/nagios/libexec/check_smart -i ata -d $ARG1$

Nagios Service:
define service{
use generic-service
host_name XXXX
service_description S.M.A.R.T. /dev/sda1
check_command check_nrpe!check_smart!/dev/sda1
}