Possible errors are displayed via the four status signals: 'malfunction‘, 'function control‘, 'maintenance requirement‘ and 'beyond specification‘. It is important to note that these only apply to the specific device, and not the entire installation.
Within the confines of an expert roundtable, users and field device producers discussed the current state of NE 107. One positive aspect mentioned was the fact that, by now, current field devices recognize NE 107.
Additionally, users avowed themselves to use more diagnostics in their field devices since the standardized and producer-independent status signals ease handling and, in case of a problem, enable users to forward information to the people depending on it.
It is a preference of users that alongside the error message the specific cause of error is displayed. However, to do so one has to continue to rely on the expertise of operators. Since the issue at hand, however, is too complex, it seems more reasonable to display a simple error message without specification, rather than taking the risk of displaying a false signal.
Especially in times of shrinking numbers of experts in the field of engineering and maintenance, it is becoming more and more important that diagnosis tools are implemented at the construction stage, are easy to handle and are comprehensive.
At the moment only a small percentage of field devices have a fieldbus connection. The majority of devices are still equipped with 4-20mA or Hart. Therefore, users also ask to employ the already existing Hart information for diagnostic purposes. These would be sufficient if one simply wants to detect the state of vibrancy or health of the device, but it fails to deliver information within 100 msec. Additionally, one would easily need an entire day to browse the status of a large-scale installation without a fieldbus, since one would have to move from one device to another to read their current state.
Users also identified development potential in the integration of NE 107 into guidance systems. At this point, it would be technically impossible to integrate diagnostic data from several producers in one guidance system. Therefore, users bargained for standardized access in order to directly read diagnostic data, independent of asset management or engineering systems used by the guidance system. Much of the relevant information is then deducible via the data history, which can be monitored and compared to others. The OPC- UA gateway as it is intended by the FDI could be a solution to this problem.
At the end of the discussion, both sides concluded that they are on the right path and they will continue to collaborate in the future.
>> Peter Ebert, [email protected], is the new editor for sensors, industrial vision and measurement for SPS Magazin in Germany. He was chief editor for an automation and measurement magazine for 14 years.
