Rockwell Automation 1756-OF8H ControlLogix HART Analog I/O Modules - Manual (Page 66)

66 Rockwell Automation Publication 1756-UM533C-EN-P - February 2011
Chapter 4 1756-IF8H HART Analog Input Module
1756-IF8H Channel Status Tags
Table 9 describes the channel status tags.
Specifications and
Certifications See the 1756 ControlLogix I/O Modules Specifications Technical Data,
publication
1756-TD002 , for specific module specifications and certifications.
Table 9 - Tags That Show Channel Status
Tag Bit Description
ChxCalFault 7 This bit is set if an error occurs during calibration for Channel x, causing a bad calibration. Also sets CalFault in the
Module Faults.
ChxUnderrange 6 This bit is set when the analog signal is less than or equal to the minimum detectable signal. Because the signal cannot
be measured, it may be significantly below the minimum value. Also sets ChxFault in the Channel Faults.
ChxOverrange 5 This bit is set when the analog signal is greater than or equal to the maximum detectable signal. Because the signal
cannot be measured, it may be significantly above the maximum value. Also sets ChxFault in the Channel Faults.
ChxRateAlarm
(1)
4 This bit is set when the rate of change between input samples for each channel exceeds the specified rate-alarm trigger
point for the channel. Both positive and negative changes can cause this alarm.
ChxLAlarm 3 This bit is set when the requested input value is less than the configured low limit value. It remains set until the
requested input is greater than the low limit. If the bit is latched, it remains set until it is unlatched.
ChxHAlarm 2 This bit is set when the requested input value is greater than the configured high limit value. It remains set until the
requested input is less than the high limit. If the bit is latched, it remains set until it is unlatched.
ChxLLAlarm 1 This bit is set when the requested input value is less than the configured low low limit value. It remains set until the
requested input is greater than the low low limit. If the bit is latched, it remains set until it is unlatched.
ChxHHAlarm 0 This bit is set when the requested input value is greater than the configured high high limit value. It remains set until the
requested input is less than the high high limit. If the bit is latched, it remains set until it is unlatched.
(1) Alarm bits 0…4 in the Channel Status word do not set additional bits at any higher level.