Rockwell Automation Allen-Bradley POINT Guard - Analog I;O Status Data

Rockwell Automation Publication 1734-UM013J-EN-P - July 2014 43
Safety Inputs, Safety Outputs, and Safety Data Chapter 2
Analog I/O Status Data
Individual input status indicates whether each analog input point is normal
(ON) or faulted (OFF). In addition, the following diagnostic data is monitored:
• User 24V Supply Overrange or Underrange
• Sensor Power Overcurrent or Undercurrent
• Channel Signal Overrange or Underrange
• Broken Wire Detected (4…20 mA current mode)
• Single-channel Discrepancy Error (channel fault)
In SIL 2 or SIL 3 operation, a single-channel discrepancy error occurs
when both measurements (internal to the module) of the same input signal
are not within tolerance. If a single-channel discrepancy occurs, indicating
a problem with the module, input status is set to zero and a zero input
value is reported for that channel.
• SIL 3 Dual-channel Discrepancy Error (channel fault)
• Alarms
– High High and Low Low Alarm Overrange or Underrange
– High and Low Alarms Overrange or Underrange
– Dual-channel Tachometer Dual Low Inputs Detected
– Tachometer Frequency Overrange or Underrange
The alarm status is reported in the Alarm Status attribute for each channel.