Spectrum Controls 1746sc-NI8u - Manual (Page 61)

Chapter 4: Channel Configuration, Data, and Status 49
Under-Range Error (Bit 13)
This bit is set (1) whenever a configured channel detects an under-range
condition for the channel data. An under-range condition exists when the
input value is equal to or below the specified lower limit of the particular
sensor connected to that channel.
Over-Range Error (Bit 14)
This bit is set (1) whenever a configured channel detects an over-range
condition for the channel data. An over-range condition exists when the
input value is equal to or above the specified upper limit of the particular
sensor connected to that channel.
Channel Error (Bit 15)
This bit is set (1) whenever a configured channel detects an error in the
configuration word, or an error has occurred while acquiring the ADC
data value. If during the auto-calibration process, the module detects an
out-of-range condition for the filter frequency selected for the channel, the
channel error bit will be set. An out-of-range condition occurring during
auto-calibration would be the result of an overly noisy environment,
whereby the module cannot maintain accuracy specifications, thus flagging
an error. The error bit is cleared when the error condition is resolved.
The channel data word is still updated during a period of auto-calibration
filter frequency tolerance errors, but accuracy may be degraded.