Industrial Alarm Systems: DTMs Enable Access to the Advanced Diagnostics

Introduction

Author

Amit Ajmeri, Yokogawa Corporation of America

As plant operations become more complex, proper alarm monitoring becomes very critical to manage the correct operation of the plant. Nowadays digital field devices are increasingly used due to their advanced diagnostic capabilities. With an increased volume of information created by the growing number of parameters from field devices, event and alarm functions issue more detailed information. Today a new standard, NE107, provides standardized alarm functions, allowing end users to take control of setting alarms based on their application needs to eliminate unnecessary alarm flooding. This article introduces the NE107 standard and provides insight into how a Frame Application (FieldMate) and NE107-compliant device DTMs enable access to the advanced diagnostics and delivery of alarm status information to the right people at the right time in one standardized interface.

NE 107 Field Diagnostics Function

Figure 1: Flow of Alarm Information of Field Diafnostics function

NE 107NAMUR NE 107 is a standard for preventing alarm flooding and offering appropriate diagnosis information to the relevant people when necessary. It was developed as a specification for self-diagnosing field devices and yields reliable results, categorizes alarms into four standardized statuses (F: failure, C: function check, S: out of specification, and M: maintenance required). This enables users to configure diagnostics and provides detailed information for experts.

NE 107 Field Diagnostics Function of Yokogawa DTM and Flow of Alarm Information
To enhance the setting and checking of field devices in accordance with NE 107, Yokogawa has incorporated the Field Diagnostics function in its device DTMs for FOUNDATION Fieldbus and PROFIBUS. This function conforms to the FOUNDATION Fieldbus Diagnostics Profile Specification (FF-912 FS1.0) and PROFIBUS Profile for Process Control Devices Version 3.02. This section outlines the NE 107-compliant alarm setting function for the FOUNDATION Fieldbus. Figure 1 shows the flow of alarm information through this function.

Figure 2: Aggregated Field Diagnostic Alarm

The flow starts at the Extended Field Diagnostic Alarm (the bottom of Figure 1). Alarms are defined by vendors for each device, and 32 alarms are grouped each into several blocks. Yokogawa specifies 256 alarms in eight blocks. Users can select or deselect these alarms at Escalation Enable, and the selected alarms are sent to the upper layer of Manufacturer-Specific Condition, which is called Aggregated Field Diagnostic Alarms in DTM.

The selected alarms are aggregated in 32 alarms (see Figure 2). These alarms are common to transmitters, flow meters, operational devices, displays and analyzers, and they are arranged in order of priority. For each status signal, device-specific alarm bits are set.

Recommended Action

Figure 3: Configuration Windows for NE107 Diagnostics Function

To help users respond quickly and appropriately to alarms, Yokogawa provides the status window in the device DTM based on the priority of 32 aggregated field diagnostic alarms (Figure 4). The recommended action is displayed to prompt users to deal with the alarms. In addition, the status (F, C, S, or M) of each aggregated field diagnostic alarm is displayed in the tree view. By unfolding each alarm, users can check detailed alarm information (status of respective extended field diagnostic alarms).

Conclusion

Figure 4: Field Diagnostics Status Window

As digital field devices become more diverse and offer greater functionality, it’s important for vendors to incorporate newer standards within their smart instrumentation and advanced control systems. When coupling NE107 field diagnostics functions and the delivery method enabled with FDT Technology, both of which are incorporated in Yokogawa’s FieldMate R2.06, users have created peace of mind, ensuring their assets and available intelligent information are being used to their full potential for improved operations and maintenance.

* FieldMate and EJX are registered trademarks of Yokogawa Electric Corporation.

*FOUNDATION Fieldbus, HART, and PROFIBUS are registered trademarks of the Fieldbus Foundation, HART Communication Foundation, and PROFIBUS User Organization, respectively.