How to Configure OPC Expert to Send Email Alerts When a Value Drops Below a Threshold

OPC Expert supports automated email notifications triggered by OPC data conditions, including value threshold breaches. When a monitored tag drops below a defined limit, OPC Expert detects the condition and executes the configured action, which can include sending a timestamped email alert to one or more recipients. This capability requires no external scripting and no SCADA system. It is configured directly within OPC Expert using the Trigger OPC Events feature.

How Trigger Conditions Are Configured

Within OPC Expert, you define a trigger by selecting the OPC item to monitor and specifying the condition that must be met for the trigger to fire. For a threshold scenario, you configure the condition to detect when the value falls below a specific number. Multiple conditions can be combined in a single trigger, allowing you to build logic such as “value below threshold AND data quality is good,” which prevents false alerts caused by communication failures rather than actual process changes.

Email Notification Setup

When the trigger fires, OPC Expert can send an email that includes the item name, the timestamp of the event, the value that caused the trigger, and any custom message text you include. The email is sent using SMTP configuration defined within OPC Expert. The notification is generated automatically without user interaction and includes enough diagnostic context for a recipient to understand immediately what occurred and when. This is useful for operators or maintenance staff who need to be informed of abnormal conditions without being physically present at the control system.

Additional Actions Beyond Email

The same trigger configuration can execute additional actions alongside or instead of email. OPC Expert can play a sound alert, execute a batch file or PowerShell script, reconnect to an OPC server, or initiate a failover to a redundant system. These actions can be combined, so a single threshold event can simultaneously send an email, execute a corrective script, and log the event. This flexibility makes the trigger system applicable to a wide range of monitoring and response scenarios beyond simple alerting.

Relevant Tools

Trigger OPC Events is the OPC Expert feature that defines condition-based triggers on OPC data and executes automated responses including email notifications, sound alerts, script execution, and server failover. It monitors data in real time and requires no installation.

Monitor OPC Data is the OPC Expert module that provides continuous real-time monitoring of OPC components and can be configured with customizable alerts that notify users when issues are detected, complementing the threshold-based triggering in Trigger OPC Events.

Summary

OPC Expert can send email alerts automatically when an OPC tag value drops below a defined threshold using its Trigger OPC Events feature. Trigger conditions are configurable, can combine multiple logic criteria, and can execute multiple actions simultaneously. No external scripting or additional software is required to set up threshold-based alerting.