Rockwell Automation 1746-NR8 SLC 500 RTD/Resistance Input Module User Manual - Manual (Page 71)

Publication 1746-UM003A-EN-P
Channel Configuration, Data, and Status 4-23
Channel Filter Frequency (Bits 9 and 10)
The channel filter frequency bit field reflects the filter frequency you selected
in bits 9 and 10 of the configuration word when the channel is enabled. This
feature is active for all input types. If the channel is disabled, these bits are
cleared (0).
Channel Enable Status (Bit 11)
The channel enable status bit indicates whether the channel is enabled or
disabled. This bit is set (1) when the channel enable bit is set in the
configuration word (bit 11) and there is valid data in the channel’s data word.
The channel status bit is cleared (0) if the channel is disabled.
Calibration Error (Bit 12)
If a calibration error occurs this flag is set. A calibration error is a fatal error. It
indicates that the module was not able to complete its on board calibration
process. A calibration error could effect individual channels, but may get set on
all channels at the same time if the ADC has a hardware fault.
Broken Input Error (Bit 13)
This bit is set (1) whenever an enabled channel detects a broken input
condition. A broken input error is declared for the following reasons:
•
Open-circuit - excitation current is less than 50% of the selected current.
•
Short-circuit - calculated lead wire compensated RTD resistance is less than 3
ohms.
The open-circuit error is active for all RTD and resistance inputs, while the
short-circuit error is valid only for RTD inputs. If a broken input is detected,
the module sends either zero, upscale, or downscale data to the channel data
word for that channel, depending on your channel configuration bits 6 and 7.
A broken input error takes precedence over an out-of-range error states. There
is not an out-of-range error when an open-circuit or short circuit is detected.
This bit is cleared if the channel is disabled or if the channel operation is
normal.