Capturing TP700 Project Name in TIA Portal V13 VBScript

Problem Overview

When commissioning a fleet of SIMATIC TP700 Comfort panels running WinCC Comfort V13, the VBScript runtime environment does not expose a built-in function that returns the active project file name. Any VBScript that needs to stamp a unique file name (for example \Storage Card SD\PanelA History.txt) must therefore obtain the panel identifier from a tag rather than from a runtime API call.

The two field-proven workarounds that engineers use on TIA Portal V13 are:

1. An internal string tag declared with a per-project start value, optionally marked persistent (retentive) so the value survives a power cycle.
2. The same tag written from the start screen's Loaded event with the project-specific literal, executed automatically at runtime every time the project boots.

For newer TIA Portal versions (V17 and later, including the V20 Unified runtime), a third option is available through the TIA Portal Openness API: the device name can be read from the engineering project, then pushed down to the runtime as a tag value during compile/transfer. This article walks through all three methods with concrete steps, parameter tables, VBScript samples, and a commissioning checklist.

Prerequisites

Why VBScript Cannot Read the Project Name Directly in V13

In WinCC Comfort V13 the HMIRuntime object exposes the Tags, Screens, Alarms, Languages, Devices, ProcessValues, and DataLogs collections, but the object model does not include a member that returns the .hmi13 / .ap13 project name. Functions such as HMIRuntime.BaseScreenName, HMIRuntime.CurrentLanguage, and HMIRuntime.ProjectPath either do not exist or return only internal pointers, not the human-readable project name visible in the project tree.

The only runtime identifiers that WinCC Comfort V13 makes available through standard system tags are limited to entries such as @LocalMachineName, @UserName, @Date, @Time, and a small set of PLC connection diagnostics. The project file name is not exposed through this channel, which forces the engineer to supply the name through the project data instead of reading it from the runtime.

Method 1 — Retentive Internal Tag with Start Value

The simplest approach uses an internal HMI tag whose start value carries the panel identifier. The tag is marked persistent, so the value remains intact after the panel is powered off. VBScript then reads the tag through the SmartTags collection and concatenates it into the file path. This was the first suggestion that emerged in the original support exchange because it requires no VBScript knowledge beyond reading a tag and concatenating a string.

Step-by-step tag configuration

1. In the TIA Portal project tree, expand HMI Tags and double-click Default tag table.
2. Add a new tag with the following properties (right-click the table header and select Add new tag):

To enable persistence, open the tag's Properties inspector, select the Settings group, and tick Persistent. TIA Portal stores the persistent area in the panel's internal flash and recreates the values on the next boot. The reserved size on TP700 Comfort is 128 KB; the persistent tag consumes 80 + 4 bytes (length field + null terminator), so a fleet of 30 panels can share the configuration safely.

VBScript that reads the tag

' VBS313 - Write data file using persistent panel name
Dim fso, ts, panelName, filePath, sLine

Set fso = CreateObject("Scripting.FileSystemObject")

panelName = SmartTags("HMI_Panelname")              ' reads the retentive WString
If Len(panelName) = 0 Then panelName = "Unknown"

filePath = "\Storage Card SD\" & panelName & " History.txt"

Set ts = fso.OpenTextFile(filePath, 8, True, -1)     ' 8 = ForAppending, True = create, -1 = Unicode
sLine = FormatDateTime(Now, 0) & "," & CStr(SmartTags("DB100_REAL"))
ts.WriteLine sLine
ts.Close

Set ts = Nothing
Set fso = Nothing

Method 2 — SetTag on Start Screen Loaded Event

Step-by-step start screen event

1. Open the project tree, expand Screens, and double-click the start screen (typically Screen_1).
2. In the screen's Properties panel, switch to Events.
3. Under the Loaded event row, click the empty field, choose SetTag (or SetTagValue) from the system function list.
4. Configure the function call:

5. Repeat the function call for every tag whose start value needs to be project-specific. The Loaded event fires once at the end of the runtime startup, after VBScript globals are initialised.

How to update 30 panels at once

The event definition lives in the start screen, which is part of the compiled project. To roll out the change:

1. Open each project (or use a master project with project-specific text library entries).
2. Open the start screen's Loaded event.
3. Edit the literal value of the SetTag call.
4. Recompile and download only the HMI runtime, not the PLC build.

For very large fleets, drive the literal from a tag that the PLC writes on first communication, removing the need to touch each panel's project at all:

' On PLC side (S7-1200 / S7-1500)
' DB100.DBB0 = ASCII string of panel name, e.g. 'PanelA\0'
' Use a standard PUT/GET or S7 connection to write into HMI tag HMI_Panelname

Set Acquisition mode for HMI_Panelname to Cyclic in operation with a 2 s cycle. The PLC writes the value once at boot, and the VBScript history function picks it up on the next append.

Method 3 — TIA Portal Openness API for TIA Portal V17+

Engineers migrating from V13 to TIA Portal V17 or later can automate the panel-name assignment through the TIA Portal Openness API. The API exposes the HMI device Name property so a build pipeline can stamp the literal directly into the tag's start value before compiling. The official Siemens reference for the device-name path on RT Unified targets is Accessing device name for HMI Panel (RT Unified).

C# example (Visual Studio 2019/2022 with Openness V20)

using Siemens.Engineering;
using Siemens.Engineering.Hmi;

TiaPortal tia = new TiaPortal(TiaPortalMode.WithUserInterface);
Project project = tia.Projects.Open(new FileInfo(@"C:\Projects\Fleet\PanelA.ap17"));

foreach (HmiTarget hmi in project.GetChildrenOfType<HmiTarget>())
{
    HmiTagTable table = hmi.TagTables.Find("DefaultTagTable");
    HmiTag tag = table.Tags.Find("HMI_Panelname");
    tag.StartValue = hmi.Name;          // write the device name into the start value
}

project.Save();
project.Close();
tia.Dispose();

Building the History File Path in VBScript

The complete VBScript that combines the tag-based panel name with the SD card path, the timestamp, and the data payload is:

' VBS313-History - Log a single value to the panel-specific history file
Option Explicit

Const ForAppending = 8
Const TristateTrue = -1

Dim fso, ts
Dim panelName, filePath
Dim logLine

Set fso = CreateObject("Scripting.FileSystemObject")

' 1. Pull the panel name from the internal HMI tag
panelName = SmartTags("HMI_Panelname")
If Len(panelName) = 0 Then panelName = "Default"

' 2. Build the path. SD card root on TP700 Comfort is "\Storage Card SD\".
filePath = "\Storage Card SD\" & panelName & " History.txt"

' 3. Compose the CSV line
logLine = FormatDateTime(Now, 0) & ";" _
        & CStr(SmartTags("DB100_REAL")) & ";" _
        & CStr(SmartTags("DB100_INT"))

' 4. Open the file in append mode, create if it does not exist
Set ts = fso.OpenTextFile(filePath, ForAppending, True, TristateTrue)
ts.WriteLine logLine
ts.Close

Set ts = Nothing
Set fso = Nothing

Path constants for TP700 Comfort

Persistent Storage Configuration on TP700

The TP700 Comfort allocates 128 KB of internal flash to the persistent tag area. Configure it from HMI Device > Properties > Persistent storage:

Verification and Commissioning Procedure

1. Compile and download. Right-click the HMI station in the project tree and select Compile > Software (rebuild all). Transfer the resulting image via PROFINET or Ethernet using the Download to device button.
2. Validate with RT simulator. In the TIA Portal V13 menu, choose Online > Simulation > Start with tag simulator. Trigger the VBScript from a button event. Confirm that the file appears under the simulator's virtual SD card path.
3. Power-cycle test. Disconnect the 24 V supply for at least 30 s, then restore. Verify that HMI_Panelname still contains the expected literal when you read it back from a diagnostic screen.
4. Inspect the file. Remove the SD card, insert it into a Windows PC, and confirm the file name pattern matches PanelA History.txt, PanelB History.txt, etc.
5. Compare panel content. Use fc /B *.txt on the SD card to confirm that the bytes appended by PanelA differ from those appended by PanelB. If two panels write to the same file, the SD card root is being mistyped.
6. Audit with ProSave. Use Siemens ProSave to back up the panel image, then restore on a spare TP700 to verify the persistent tag survives a transfer. ProSave is bundled with TIA Portal under Start > Siemens Automation > ProSave.

Troubleshooting Matrix

Migration to TIA Portal V17 / V20 Unified

Teams planning a move off WinCC Comfort V13 should evaluate the following differences:

For new projects, prefer the Unified runtime so the panel name is available without an extra tag. For existing V13 fleets, Method 1 or Method 2 keeps the script compatible without recompilation.

FAQ