Rockwell Automation 1746-NR4 SLC RTD/Resistance Input Module User Manual - Manual (Page 85)

Publication 1746-UM008B-EN-P - December 2006
Channel Configuration, Data, and Status 85
Channel Filter Frequency (Bits 9 and 10)
The channel filter frequency bit field reflects the filter frequency you
selected in bits 9…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.
Excitation Current (Bit 12)
This bit indicates the excitation current setting made to bit 12 of the
channel’s configuration word when the channel is enabled. If the
channel is disabled, this bit is cleared (0).
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 reasons that include:
• open-circuit - excitation current is less than 50% of the selected
current.
• short-circuit - calculated lead wire compensated RTD resistance
is less than 3
Ω.
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 will not be 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.