Difference between process alarms and system alarms

Process alarms can be understood as alerts issued when process parameters exceed their limits, with different levels of severity. System alarms refer primarily to the alerts generated when there are faults in the DCS system, such as communication failures or the inability to access historical data.

Can it be understood that process alarms are abnormal alarms that occur when the set alarm thresholds are exceeded, while the rest are system alarms?

Process alarms are those that are triggered by process parameters, while system alarms refer to those generated by the control system itself, such as template communication issues.

Could you elaborate on what other types of alarms exist in a system besides communication alarms?

This post was last edited by ZhiGE on 2020-4-15 at 16:42. 1. Control and instrumentation system alarms (abbreviated as system alarms): Alarms resulting from hardware or software failures in the control and instrumentation system. This information is very useful, but it should be noted that it is related to the operator and should be easy for the operator to understand. These alarms are often misused. Note that it is best to separate the display of these system alarms from those of process alarms. Alarms from the control and instrumentation system: These are generated as a result of faults in the hardware or software of this system. They can be useful, but care must be taken to ensure that they are relevant to the operator and easy for him/her to understand. Such alarms are often misused. It may be advisable to be able to separate the display of these system alarms from those related to the process itself. 2. Process alarms: These are alarms related to process parameters and operations. EEMUA191 further classifies them into absolute alarms, deviation alarms, rate-of-change alarms, calculated alarms, inconsistency alarms, first-time occurrence alarms, and so on. 3. Let’s talk again about the importance of alarms. In the LOPA layer, alarms and human intervention are located in the third layer of this protection system. If operators respond promptly to the alarm alerts, the process will return to its normal operating state; however, ignoring the alarms or failing to manage them properly can lead to interlocks being activated. Therefore, it is necessary to implement alarm grading in order to prevent an overload of alarms; invalid alarms should be removed to reduce the workload on operators, and alarms can be handled prioritarily based on their severity level. Some control systems are equipped with an Advanced Alarm Management System (AAS) to evaluate the effectiveness of the alarm system and provide optimization recommendations. The following are the standards regarding alarm management: IEC 62682-2014 Management of alarm systems for the process industries; ANSI-ISA-18.2-2016 Management of Alarm Systems for the Process Industries; EEMUA 191 Alarm systems – a guide to design, management and procurement

Process alarms are classified under process control, while system alarms are classified under instrumentation.

I totally get it now, thanks! ! ! ! ! ! ! !