Alarm | AseptSoft Documentation

An Alarm defines a monitoring condition that triggers notifications when a process variable exceeds defined limits. Alarms are a key part of process safety and operator awareness, following ISA-18.2 alarm management principles.

💡 In pharmaceutical terms: Alarms protect your process by alerting operators when critical values go out of range — for example, when a CIP tank temperature exceeds the safe limit, or when WFI conductivity rises above specification. A well-configured alarm system is essential for GMP compliance and patient safety.

📋 Properties

Identity and Trigger

Property	Type	Description
Name	Text	Unique identifier for the alarm (e.g., "HighTemp_CIPTank")
Tag Name	Text	The associated tag or variable being monitored
Condition Expression	Text	The trigger condition expression

📏 Limit Configuration

Property	Type	Default	Description
Limit Type	Selection	High	The type of limit (see table below)
Setpoint HH	Decimal	—	High-High threshold value
Setpoint H	Decimal	—	High threshold value
Setpoint L	Decimal	—	Low threshold value
Setpoint LL	Decimal	—	Low-Low threshold value
Discrete State	Text	—	State name for discrete alarms
Deadband	Decimal	0	Deadband value to prevent alarm chattering
Delay On (seconds)	Decimal	0	Time the condition must persist before triggering
Delay Off (seconds)	Decimal	0	Time the condition must clear before returning to normal

🏷️ Classification

Property	Type	Default	Description
Priority	Selection	Medium	How urgently the operator should respond (see below)
Severity	Selection	Normal	How serious the consequence is (see below)
Classification	Selection	Process Deviation	Quality, Safety, Environment, Maintenance, Process Deviation, Equipment Protection, or Regulatory

💬 Messaging

Property	Type	Description
Alarm Message	Text	Message displayed when the alarm triggers
Engineering Units	Text	Unit description for the alarmed value
Operator Response	Text	Recommended response for the operator
Consequence If Ignored	Text	What happens if the alarm is not addressed

✅ Acknowledgement and Shelving

Property	Type	Default	Description
Acknowledgement Rule	Selection	Require operator acknowledgment	See table below
Shelving Rule	Selection	Allow timed shelving	See table below
Max Shelve Duration (min)	Integer	480	Maximum time an alarm can be shelved
Flood Protection Enabled	Yes/No	Yes	Whether flood protection is active
Flood Suppression (seconds)	Integer	10	Time window for flood suppression

📡 Routing and Return-to-Normal

Property	Type	Default	Description
Routing	Flags	HMI Popup + Historian Log	How the alarm is delivered (combinable): Horn, Light, HMI Popup, Email, SMS, Historian Log
Return-to-Normal	Selection	Auto-clear	How the alarm clears when the condition returns to normal

📊 Limit Types Explained

Limit Type	What It Means	Typical Use
High-High (HH)	Emergency high — the value is dangerously high	Immediate action required — possible equipment damage or safety risk
High (H)	Warning high — the value is above the normal operating range	Operator attention needed — take corrective action soon
Low (L)	Warning low — the value is below the normal operating range	Operator attention needed — take corrective action soon
Low-Low (LL)	Emergency low — the value is dangerously low	Immediate action required — possible equipment damage or safety risk
Discrete (on/off)	Triggers on a specific state change rather than an analog value	Equipment state change — e.g., a valve unexpectedly changing position

🏭 Example: A CIP tank temperature alarm might have: LL = 5 °C, L = 65 °C, H = 92 °C, HH = 98 °C — providing graduated warnings before reaching dangerous levels.

⚖️ Priority vs Severity

Concept	Question It Answers	Values
Priority	"How quickly must the operator respond?"	Critical > High > Medium > Low > Diagnostic
Severity	"How serious is the consequence?"	Emergency > Urgent > Normal > Advisory > Log Only

A Critical priority + Emergency severity alarm demands immediate operator action with maximum notification (horn, HMI popup, email, etc.). A Low priority + Log Only severity alarm is recorded for trending but does not interrupt the operator.

✅ Acknowledgement Rules

Rule	What It Means
Require operator acknowledgment	The operator must actively acknowledge the alarm before it clears from the active list
Auto-acknowledge	The alarm is automatically acknowledged when the condition returns to normal
No acknowledgment needed	The alarm is informational only — no operator action required
Acknowledge with mandatory comment	The operator must acknowledge AND provide a written comment explaining the response

📖 How To: Configure Alarms for a CIP Tank

Open Module Data — Navigate to the Data panel in the Module Ribbon and open the Module Data window.
Go to the Alarms tab — Select the Alarms section.
Create alarm definitions — For each critical variable (temperature, pressure, level, flow), create alarm entries with appropriate limit types and setpoints.
Set priorities and severities — Use Critical/Emergency for safety-related alarms, Medium/Normal for process deviations, and Low/Advisory for informational alerts.
Configure acknowledgement — Safety-critical alarms should "Require operator acknowledgment". Routine alarms can use "Auto-acknowledge".
Set routing — Ensure critical alarms trigger Horn + HMI Popup + Historian Log. Lower-priority alarms may only need HMI Popup + Historian Log.
Add operator guidance — Fill in the "Operator Response" and "Consequence If Ignored" fields to help operators respond correctly.

🏭 Example: CIP Tank Temperature Alarms

Alarm Name	Tag	Limit Type	Setpoint	Priority	Severity	Acknowledgement	Routing
HighHighTemp_CIPTank	TT-101	High-High	98 °C	Critical	Emergency	Require operator acknowledgment	Horn + HMI Popup + Historian Log
HighTemp_CIPWarn	TT-101	High	92 °C	Medium	Normal	Auto-acknowledge	HMI Popup + Historian Log
LowTemp_CIPWarn	TT-101	Low	65 °C	Medium	Normal	Auto-acknowledge	HMI Popup + Historian Log
LowLowTemp_CIPFail	TT-101	Low-Low	5 °C	High	Urgent	Require operator acknowledgment	Horn + HMI Popup + Email + Historian Log

🏭 Pharma context: During a CIP caustic wash, the solution must maintain a minimum temperature (typically 65-80 °C) for effective cleaning. The Low alarm warns operators when temperature drops below the minimum, while the Low-Low alarm indicates a failure that requires investigation and possible batch review.

🛠️ Common Operations

Operation	Description
Create	Add a new alarm from the Module Data window
Edit	Modify alarm properties
Duplicate	Create a deep copy of an alarm with all properties
Delete	Remove an alarm
Search	Filter by name, tag name, alarm message, operator response, or condition expression
Excel Export	Export alarms to Excel
Excel Import	Import alarms from Excel

📋 Module Data — All module data types
🛡️ Interlock — Safety interlocks that can trigger on alarm conditions
🔁 Control Loop — Control loops with alarm integration
🧠 Algorithm Design — Condition logic that references alarms
📏 Parameter — Parameters used as alarm setpoints