HMI​.Trace

Logs a text message. This is typically done to debug the project.

Syntax

HMI.Trace(strOutputMessage)

strOutputMessage

A string to be logged as a message. The name of the tag. Specify a string enclosed in quotes (double quotes or single quotes), or a Python variable containing the name of the tag (do not use quotes). If this parameter is not enclosed in quotes, it will be treated as a Python variable, potentially causing an exception if this variable does not exist. See the examples for more information.

Note: Tag values can be accessed using HMI.GetTagValue. The argument can only be a string; the examples show the use of str() and F-String.

Note: Tag Properties are accessible using the syntax HMI.GetTagValue('Tag->TagProperty'). Some tag properties may need to be cast to a string (using str()), even in an F-String.

Return value

This function returns no value.

Notes

HMI.Trace accesses the built-in function Trace.

Enable runtime Python logging to show HMI.Trace messages:

• In the AVEVA Edge Studio development environment, and the SCADA or Embedded HMI runtimes, the HMI.Trace messages appear in the Studio Output window or the runtime LogWin tool.

• In the IoT View runtime, the HMI.Trace messages appear in the IoT View runtime log.

Examples

Display static text that reports a specific event:

HMI.Trace("Beginning step 5.")

Display the text value of Python variable pyStrVar:

HMI.Trace(pyStrVar)

Display the date by referencing the appropriate system tag:

HMI.Trace(str(HMI.GetTagValue("Date")))

Concatenate static text and tag references to form a complex message:

HMI.Trace(f"The current time is: {HMI.GetTagValue('time')}.")

HMI.Trace("The current time is: " + str(HMI.GetTagValue('time')) + ".")

HMI.Trace(f"The value of myTag is: {HMI.GetTagValue('myTag')}")

HMI.Trace(f"The quality of myTag is: {HMI.GetTagValue('myTag->Quality')}")

HMI.Trace(f"The current datetime is: {str(HMI.GetTagValue('Second->TimeStamp'))}")