Data Forwarders

The Data Forwarders feature allows ENVISION to continuously push historical data, alarms, and events to an external database in real time. This is useful for integrating ENVISION with third-party reporting tools, data lakes, ERP systems, or any external SQL database.

Each Data Forwarder runs as an independent background thread, connecting to a remote database on a configurable interval and forwarding records in batches using a watermark-based mechanism — ensuring no records are skipped or duplicated across restarts.

Supported Databases

Database	Connection Type
SQL Server	Remote TCP/IP with username & password
MySQL	Remote TCP/IP with username & password
SQLite	Local file path

Managing Data Forwarders

Adding a Data Forwarder

1. Enter a Name and select a Database Type in the add row at the top of the list.

2. Optionally enter a Description.

3. Click Add.

Enabling / Disabling

Use the toggle switch on each row to enable or disable an individual forwarder.

Use the Enable All toggle in the header to enable or disable all forwarders at once. A confirmation dialog will appear.

Selecting & Bulk Actions

Use the checkbox on each row to select individual forwarders.

Use the Select All checkbox in the header to select all visible forwarders.

Export — exports the selected forwarders to a JSON file.

Delete — deletes the selected forwarders after confirmation.

Settings

Click the gear icon on a row to open the Settings modal for that forwarder.

Settings

Connection

Field	Description
Verbose	0 = silent, 1 = connection events, 2 = record counts.
Connection String	The database connection string. Use the clipboard icon to load a template based on the selected Database Type.
Mode	Direct Insert — executes a SQL INSERT. Stored Procedure — calls a stored procedure. Not supported for SQLite.

Connection String Templates

Database Type	Template
SQL Server	Server=myserver;Database=mydb;User Id=myuser;Password=mypassword;
MySQL	Server=myserver;Database=mydb;Uid=myuser;Pwd=mypassword;
SQLite	Data Source=C:\path\to\database.db;

💡 Connection strings are stored in the ENVISION SQLite configuration database, protected by Windows file system access rights (admin-only).

Forward Data

Forwards records from the HistoricData table.

Parameter	Description
@TimeStamp	Timestamp of the data record
@Device	Device name
@Variable	Variable name
@Value	Scaled value
@Raw	Raw value
@Status	Quality status

Direct Insert example:

INSERT INTO MyData (ts, dev, var, val, raw, status)

VALUES (@TimeStamp, @Device, @Variable, @Value, @Raw, @Status)

Stored Procedure example (SQL Server):

EXEC sp_InsertData @TimeStamp, @Device, @Variable, @Value, @Raw, @Status

Stored Procedure example (MySQL):

CALL sp_InsertData(@TimeStamp, @Device, @Variable, @Value, @Raw, @Status)

Forward Alarms

Forwards records from the HistoricAlarms table.

Parameter	Description
@AlarmId	Unique alarm identifier
@OnTime	Time the alarm became active
@OffTime	Time the alarm was cleared (nullable)
@Severity	Alarm severity level
@Asset	Asset name
@Message	Alarm message
@Args	Additional arguments (nullable)

Direct Insert example:

INSERT INTO MyAlarms (alarmid, ontime, offtime, severity, asset, message, args)

VALUES (@AlarmId, @OnTime, @OffTime, @Severity, @Asset, @Message, @Args)

Forward Events

Forwards records from the HistoricEvents table.

Parameter	Description
@OnTime	Time of the event
@Asset	Asset name
@Identity	Event identity
@Message	Event message
@Args	Additional arguments (nullable)

Direct Insert example:

INSERT INTO MyEvents (ontime, asset, identity, message, args)

VALUES (@OnTime, @Asset, @Identity, @Message, @Args)

Performance

Field	Description
Interval (ms)	How often the forwarder runs in milliseconds. Default: 5000 (5 seconds).
Batch Size	Maximum number of records forwarded per cycle. Default: 100.

Watermarks

ENVISION uses a watermark mechanism to track which records have been forwarded. The last forwarded ID for each data type is stored persistently and survives restarts.

Field	Description
Last Forwarded Data ID	ID of the last successfully forwarded data record.
Last Forwarded Alarm ID	ID of the last successfully forwarded alarm record.
Last Forwarded Event ID	ID of the last successfully forwarded event record.

💡 You can manually reset a watermark to 0 to re-forward all records, or set it to a specific ID to resume from a known point.

Runtime Status

Each forwarder row displays its current runtime status and last successful forward timestamp.

State	Description
Stopped	The forwarder thread is not running.
Starting	The thread has started and is initializing.
Disabled	The forwarder is disabled via the Enable toggle.
Connected	Successfully connected to the remote database.
Forwarding	Actively sending records to the remote database.
Idle	Forwarding cycle completed, waiting for next interval.
Error	An error occurred. Check the event log for details.

SYSTEM Variables

Each Data Forwarder automatically exposes the following SYSTEM variables, accessible throughout ENVISION (displays, scripts, dashboards):

Variable	Description
{Name}.State	Current state (see Runtime Status above)
{Name}.LastForward	Timestamp of last successful forward (yyyy-MM-dd HH:mm:ss)
{Name}.LastForwardedDataId	Watermark ID for data records
{Name}.LastForwardedAlarmId	Watermark ID for alarm records
{Name}.LastForwardedEventId	Watermark ID for event records

Where {Name} is the name assigned to the forwarder.

Example: A forwarder named PlantSQL exposes PlantSQL.State, PlantSQL.LastForward, etc.

Event Log

Click the speech bubble icon on a row to view the event log for that forwarder. The log records connection events, forwarding activity, and errors, controlled by the Verbose level setting.

Tips & Best Practices

· Set Verbose to 1 during initial setup to confirm connectivity, then reduce to 0 in production.

· Keep Batch Size between 100–500 for optimal performance. Very large batches can cause timeouts on slow networks.

· Use Stored Procedure mode when the target database has strict schema validation or requires server-side business logic.

· For high-frequency data, reduce the Interval to 1000ms or less. For low-priority reporting, 60000ms (1 minute) is sufficient.

· If a forwarder shows Error state, check the event log — the full exception message is recorded there.

· Watermarks are safe to reset manually if you need to re-sync historical data to a newly created target database.