Western Digital Ultrastar DC HC310 Specifications page 193

State shall contain a value indicating the state of the device when the command was issued to the device or the reset
occurred as described below.
Value State
x0h Unknown
x1h Sleep
x2h Standby (If the EPC feature set is enabled, Standby is standby_y or standby_z)
x3h Active/Idle
(If the EPC feature set is enabled, Active/Idle is idle_a or idle_b or idle_c)
x4h SMART Off-line or Self-test
x5h-xAh Reserved
xBh-xFh Vendor specific
Note: The value of x is vendor specific.
Device error count
11.23.2.4
This field shall contain the total number of errors attributable to the device that have been reported by the device
during the life of the device. This count shall not include errors attributed to the receipt of faulty commands such as
commands codes not implemented by the device or requests with invalid parameters or invalid addresses. If the
maximum value for this field is reached the count shall remain at the maximum value when additional errors are
encountered and logged.
Western Digital Hard Disk Drive OEM Specification
179