To create a VMD file for generating messages from random text, do the following:

• Start Chameleon. In the toolbar, click New to create a new VMD file.
• From the Workspace menu, select Import Segments From Library. Select the Import segments from Library radio button, and select HL7 2.5 from the list box. Click Next.
• Select the MSH, OBX, ORC, PID and PV1 segments from the Chameleon segment library, and click Next and then click Finish.
• In the toolbar, click Message. In the Workspace panel at left, right-click the Message1 message that appears. Select Rename, and rename the message LabResult.
• In the LabResult message definition, double-click Identity. The Identity window appears.
• In the Segment column, click the ellipsis ... button. From the list box that appears, select MSH.
• In the Field column, click the ellipsis ... button. The Pick Identity Field window appears.
• Expand 9 - Message Type(MSG), and Click Message Code(ID)(String). Click OK to close the Pick Identity Field window.
• In the Identity window, in the Value column, type ORU.
• In the second row of the Identity table, in the Segment column, click the ellipsis ... button. From the list box that appears, select MSH.
• In the Field column, click the ellipsis ... button. The Pick Identity Field window appears.
• Expand 9 - Message Type (MSG), click Trigger Event(ID)(String), and click OK.
• In the Identity window, in the Value column, type R01. The message identity for the LabResult message is now set to ORU^R01:

• In the toolbar, click Table. In the Workspace panel at left, right-click the Table0 table that appears. Select Rename, and rename the table ObservationTable.
• In the ColumnName column in the first row, type ObservationIdentifier. In the second row, type ObservationValue. The table should now look like this:

• In the Workspace panel at left, double-click Message Grammar to display the Message Grammar window.
• Drag the OBX segment from the Workspace to the Segment Grammar panel in the Message Grammar window.
• In the Segment Grammar panel, select the OBX segment, then select the Optional check box.
• Drag the ObservationTable table from the Workspace to the Table Grammar panel in the Message Grammar window.

• In the Table Grammar panel, double-click ObservationTable. When the dialog box appears that warns you that you must select a grammar root, click OK.
• In the Grammar Root Selection window, click OBX and click OK. The Mapping window appears.
• In the right panel of the Mapping window, which displays the OBX segment, expand 3 - Observation Identifier, then drag 1 - Identifier from the right panel to the Mapping column in the first row of the table in the left panel.
• Drag 5 - Observation Value from the right panel to the Mapping column in the second row of the table in the left panel. The Mapping window should now look like this:

At this point, you have created the VMD file. The next step is to create the Python scripts that process the database data and generate the outgoing messages.