How do you classify and grade alarms in DCS systems? Those with proven experience are welcome to share it

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This post was last edited by 328104062 on 2016-6-29 00:07. As the title indicates, the issue that needs to be resolved is: taking the CS3000R system as an example, implementing classification of alarms within a DCS system (different HIS for different types of alarms) as well as hierarchical organization (different sound levels, sounds, frequencies, screen flashing, pop-up windows, etc., for different alarm levels). The current situation is that alarms are not organized hierarchically nor by operation station; whenever an alarm occurs in a certain domain, it is displayed on all operation stations within that domain, regardless of which device or position is involved. For example, in the FAR03 domain, there are devices such as reformers, hydrogenation units, hydrogen production units, and benzene extraction units. Each of these devices has its own HIS, and different personnel operate these HISs, but the alarms are identical – the personnel working in the hydrogen production unit receive the same alarms as those working in the hydrogenation unit, etc.). The consequences of this are that alarms become ineffective; if the alarms are set to sound continuously, it creates noise that interferes with work. Additionally, there are too many alarms, which can lead to complacency among operators. In the FAR03 domain, each person receives alarms from multiple devices, far beyond what the human mind can handle. Moreover, since alarms are not categorized by position, it’s difficult to determine which operator should pay attention to a given alarm or who should handle it； 3. There is no attention paid to this issue; the alarm system does not take into account the importance of actual operational parameters, as there is no classification system at all. As a result, less important alarm messages are sent to operators frequently, causing them to become indifferent to them. For example, the liquid level alarm thresholds for underground oil tanks are set at LL30% and HH70%, which are identical to those for important alarms such as those related to the liquid levels in the high-pressure tanks of hydrogenation units and the liquid separation tanks at the compressor inlet. The alerts provided after an alarm occurs (via sound and light signals) lead operators to ignore the more important alarms. 4. There is no distinction between system alarms and process alarms: in the operator’s HIS, system alarms are displayed, but ordinary operators usually do not understand the system, while process alarms appear on the DCS engineer’s station; DCS engineers, on the other hand, do not understand production processes. When all information is sent to everyone, it leads to ambiguity in job responsibilities, and it is necessary to make distinctions (for example, a DCS engineer might be responsible for inspections but fails to do so properly, then shifts responsibility by claiming that the operator failed to report system alarms). The issues that need to be addressed are: 1. Alarms within the same domain should be categorized by device. For example, in the FAR03 domain, there are devices such as reformers, hydrogenation units, hydrogen production units, and benzene extraction units. The reformer unit has 9 HIS units, numbered HIS0121 to HIS0129; these 9 HIS units should only receive alarms from the reformer unit itself. 2. Alarms within the same domain should be categorized by job role. For example, if HIS0121 belongs to the operation station for the reaction unit, then it should only receive alarms related to that specific job role, although it can also be adjusted manually to display alarms from the entire reformer unit. 3. Alarms should be classified by severity: for instance, the liquid level in the compressor inlet liquid separation tank could be classified as a level 1 alarm, with the screen parameters flashing and a buzzer sounding at a high frequency and volume ； The liquid level of the high-pressure tank is considered the second level of alarm: the screen flashes and a low-frequency, loud beep is emitted…… The temperature of the underground sludge tank constitutes the highest level of alarm; the screen flashes but no sound is produced. Additionally, the latest alarm records should be displayed below the HIS screen (3–7 items, 4 items are recommended). Of course, process engineers need to be involved in this. 4. System alarms and process alarms should be completely separate; system alarms should not appear on the operator’s HIS screen. Request for assistance: 1. How can these requirements listed in points 1, 2, 3, and 4 be implemented? Does anyone have experience in implementing such solutions? 2. How are alarms generated in DCS? Is it the controller that sends the signal or HIS? And how is the signal transmitted to the buzzer? 3. What is the difference between system alarms and process alarms in the CS3000? Which parameters are included in system alarms? (To my knowledge, these include communication between redundant optical fibers and cards, the CPU usage of the controller, the status of downloads, system time, etc.; please add any other parameters you know.) What information are recorded in system alarms?