Module Data Quality Reporting
The I/O modules indicate the quality of channel data that is returned to the
owner-controller. Levels of data quality are reported via module input tags.
IMPORTANT:
Once the condition that causes the Fault or Uncertain tag to change to 1 is removed,
the tag automatically resets to 0. You cannot change the status of the tags. These
tags are not always reset immediately after the condition is removed and typically
resets after a small delay.
The following input tags indicate the level of data quality:
- I.Chxx.Fault- When the fault bit is set, this tag indicates that the reported channel data is inaccurate and cannot be trusted for use in your application. Do not use the reported channel data for control.If the tag is set to 1, you must troubleshoot the module to correct the cause of the inaccuracy.Example causes of inaccurate data include the following:
- Channel is disabled
- Connection fault is detected
- Open Wire condition
- Underrange/Overrange condition
- Field Power Loss condition
TIP:You must troubleshoot the module for the typical causes first. - I.Chxx.Uncertain- This tag indicates that the reported channel data can be inaccurate but the degree of inaccuracy is unknown. Do not use the reported channel data for control.If the tag is set to 1, you know that the data can be inaccurate. You must troubleshoot the module to discover what degree of inaccuracy exists.Example causes of uncertain data include the following:
- Data signal outside the channel operating range
- Sensor Offset data is not a number
- Calibration fault on the channel
- Calibration is in process on the current channel or another channel in the module. See Calibration Causes Uncertain Data Quality Indication for more information.
TIP:
You must monitor the tags in your program to make sure that the application is
operating as expected with accurate channel input data.
Calibration Causes Uncertain Data Quality Indication
When a channel on the analog input module is being calibrated, the Notch Filter
setting for that channel changes to 10 Hz. This results in the
I.Chxx.Uncertain
tag being set to 1 for that channel until calibration is
completed.The Notch Filter settings for the other input channels in the module are unchanged.
However, since multiple input channels share an Analog to Digital converter in
5034-IF4IH module, all input channels in the same group slows during the calibration
process. As a result,
I.Chxx.Uncertain
tag is set to 1 for the other input
channels in that group as well.See Connection section under chapter 5034-IF4IH Details for the grouping information
of the input channels.
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