Rockwell Automation 1756-XXXX ControlLogix Analog I/O Modules - Manual (Page 88)

88 Publication 1756-UM0009C-EN-P - December 2010
Chapter 4 Non-isolated Analog Voltage/Current Input Modules (1756-IF16, 1756-IF8)
1756-IF8 Channel Status Word Bits – Floating Point Mode
Any of the Channel Status words, one for each channel, will display a non-zero
condition if that particular channel has faulted for the conditions listed below.
Some of these bits set bits in other Fault words. When the Underrange and
Overrange bits (bits 6…5) in any of the words are set, the appropriate bit is set
in the Channel Fault word.
When the Calibration Fault bit (bit 7) is set in any of the words, the Calibration
Fault bit (bit 9) is set in the Module Fault word. The table lists the conditions
that set each of the word bits.
Tag (Status
word) Bit Event that sets this tag
ChxCalFault 7 This bit is set if an error occurs during calibration for that channel, causing a
bad calibration. This bit also sets bit 9 in the Module Fault word.
Underrange 6 This bit is set when the input signal at the channel is less than or equal to the
minimum detectable signal. For more information on the minimum detectable
signal for each module, see
page 61 . This bit also sets the appropriate bit in
the Channel Fault word.
Overrange 5 This bit is set when the input signal at the channel is greater than or equal to
the maximum detectable signal. For more information on the maximum
detectable signal for each module, see
page 61 . This bit also sets the
appropriate bit in the Channel Fault word.
ChxRateAlarm 4 This bit is set when the input channel’s rate of change exceeds the configured
Rate Alarm parameter. It remains set until the rate of change drops below the
configured rate. If latched, the alarm will remain set until it is unlatched.
ChxLAlarm 3 This bit is set when the input signal moves beneath the configured Low Alarm
limit. It remains set until the signal moves above the configured trigger point.
If latched, the alarm will remain set until it is unlatched. If a deadband is
specified, the alarm will also remain set as long as the signal remains within
the configured deadband.
ChxHAlarm 2 This bit is set when the input signal moves above the configured High Alarm
limit. It remains set until the signal moves below the configured trigger point.
If latched, the alarm will remain set until it is unlatched. If a deadband is
specified, the alarm will also remain set as long as the signal remains within
the configured deadband.
ChxLLAlarm 1 This bit is set when the input signal moves beneath the configured Low-Low
Alarm limit. It remains set until the signal moves above the configured trigger
point. If latched, the alarm will remain set until it is unlatched. If a deadband
is specified, the alarm will also remain latched as long as the signal remains
within the configured deadband.
ChxHHAlarm 0 This bit is set when the input signal moves above the configured High-High
Alarm limit. It remains set until the signal moves below the configured trigger
point. If latched, the alarm will remain set until it is unlatched. If a deadband
is specified, the alarm will also remain latched as long as the signal remains
within the configured deadband.