
Rockwell Automation Publication 1756-RM001I-EN-P - May 2012
73
FLEX I/O Modules
Chapter 6
, a user-defined percentage of acceptable
deviation (that is, tolerance) is applied to the configured range of the
analog input and output (that is, range) and the result is stored (that is,
delta). This delta value is then added to and subtracted from the
monitoring analog input channel; the results define an acceptable High
and Low limit of deviation. The analog Output Feedback is then
compared to these limits to determine if the output are working properly.
The output’s OK bit preconditions a Timer run that is preset to
accommodate an acceptable fault response time and any communication
filtering, or output, lags in the system. If the monitoring input value and
the Output Feedback miscompare for longer than the preset value, a fault
is registered with a corresponding alarm.
Figure 43 - Monitoring an Analog Output with an Analog Input
The control, diagnostics and alarming functions must be performed in
sequence.
•
When wiring two analog output modules in the same application, make
sure:
–
Both modules use identical configuration.
–
The same controller owns both modules.
•
The two analog output modules must be on separate FLEX I/O rails.
They must not share the same FLEX adapter.
•
Monitor the network status bits for the associated module and make sure
that appropriate action is invoked via the application logic by these status
bits.
Timer Done
Timer
Outputs Faulted
Alarm to Operator
Outputs OK
ADD
Delta
Monitoring input
High Limit
MULT
Range
Tolerance %
Delta
Outputs Faulted
LIM
Low Limit
Output Echo
High Limit
Outputs OK
SUB
Delta
Monitoring input
Low Limit
Содержание 1756-L6 Series
Страница 24: ...24 Rockwell Automation Publication 1756 RM001I EN P May 2012 Chapter 1 SIL Policy Notes ...
Страница 60: ...60 Rockwell Automation Publication 1756 RM001I EN P May 2012 Chapter 5 ControlLogix I O Modules Notes ...
Страница 76: ...76 Rockwell Automation Publication 1756 RM001I EN P May 2012 Chapter 6 FLEX I O Modules Notes ...
Страница 120: ...120 Rockwell Automation Publication 1756 RM001I EN P May 2012 Appendix C PFD Calculations for a SIL 2 System Notes ...
Страница 126: ...126 Rockwell Automation Publication 1756 RM001I EN P May 2012 Appendix D Checklists Notes ...
Страница 133: ...Allen Bradley Motors ...