{"id":40902,"date":"2026-02-04T08:00:00","date_gmt":"2026-02-04T13:00:00","guid":{"rendered":"https:\/\/www.dmcinfo.com\/?p=40902"},"modified":"2026-01-29T16:18:57","modified_gmt":"2026-01-29T21:18:57","slug":"siemens-wincc-unified-scripting","status":"publish","type":"post","link":"https:\/\/www.dmcinfo.com\/blog\/40902\/siemens-wincc-unified-scripting\/","title":{"rendered":"A Beginner\u2019s Guide to Scripting in Siemens WinCC Unified for Advanced HMI Control"},"content":{"rendered":"\n

Industrial automation projects are always specialized\u00a0in\u00a0their application and industry, making flexibility and adaptability necessary in all forms of programming.\u00a0This extends not just to PLC controls, but to the HMI screens and devices that operators interact with regularly.\u00a0<\/p>\n\n\n\n

Sometimes, the\u00a0built-in\u00a0functions of an HMI platform\u00a0are not enough to\u00a0accomplish\u00a0the desired goal.\u00a0When creating HMI screens for Unified Basic Panels or Unified Comfort Panels, the use of scripting within components can allow for\u00a0additional\u00a0functionality not found in the basic properties of components. <\/p>\n\n\n\n

Scripts can allow for more information to be displayed without the addition of PLC logic,\u00a0such as mathematical expressions involving more than one tag.\u00a0Scripts can also be used as functions triggered by an event, such as a button press on the HMI. Siemens scripting uses JavaScript and object-oriented principles to allow engineers more flexibility by using an established language for ease of implementation.\u00a0This blog reviews the basics of WinCC Unified Scripting.\u00a0<\/p>\n\n\n\n

Accessing Scripts \u2013 Global Modules and Functions <\/h2>\n\n\n\n

When developing an HMI program, scripts can be created for use in a variety of ways.\u00a0To do so, first drill down\u00a0to\u00a0the \u201cScripts\u201d folder in the project tree under the HMI device in your project. From there, select \u201cAdd a new global module\u201d to create a container for one or more global functions. Once the global module is created, select \u201cAdd a new\u00a0global\u00a0function\u201d,\u00a0which will open the script editor.\u00a0From here, users can create their\u00a0own custom\u00a0functions.\u00a0\u00a0<\/p>\n\n\n\n

\"Siemens<\/figure>\n\n\n\n

Triggering Global Functions <\/h2>\n\n\n\n

Once a global function is created within a global module, it can be called in a variety of ways. One method is\u00a0utilizing\u00a0the \u201cScheduled Tasks\u201d feature, which allows a function to run based on a specified condition. <\/p>\n\n\n\n

For example, to run the script \u201cFunction\u201d when the HMI tag \u201ceStopPressed\u201d changes value, a scheduled task must be created. Once it is created, the default trigger\u00a0option\u00a0is \u201cTags,\u201d which\u00a0triggers on\u00a0the value change of an HMI tag.\u00a0Other trigger options include cycle times ranging from 500ms to one year, as well as alarms.\u00a0Note that selecting a short\u00a0cycle\u00a0time can cause overloads, and that a function triggered by a tag cannot write to the trigger tag.\u00a0\u00a0<\/p>\n\n\n\n

\"Siemens<\/figure>\n\n\n\n
\"Siemens<\/figure>\n\n\n\n

Once an HMI tag is selected, select the \u201cEvents\u201d tab under the task to select the function to run upon trigger. Click the dropdown under the name column to open the menu as shown, and scroll to the bottom to find \u201cScript functions\u201d>\u201dGlobal module\u201d>\u201dGlobal module.Function.\u201d<\/p>\n\n\n\n

\"Siemens<\/figure>\n\n\n\n

Once a function is selected, choose parameter values to\u00a0input to\u00a0the function for this specific run case. These parameters can be several data types, which can be selected using the dropdown in the \u201cValue\u201d column.\u00a0\u00a0<\/p>\n\n\n\n

\"Siemens<\/figure>\n\n\n\n

Accessing Scripts \u2013 HMI Components <\/h2>\n\n\n\n

HMI components have two main ways to utilize scripts: Events and Dynamic Properties. To have an HMI event trigger a script, first navigate to the HMI component and then to the \u201cEvents\u201d tab. Select the preferred trigger event, then click the button shown below to convert the function list to a script.  <\/p>\n\n\n\n

\"Siemens<\/figure>\n\n\n\n

To use a script to define a\u00a0component\u00a0property, first navigate to the\u00a0component\u00a0in question and to \u201cProperties.\u201d\u00a0In the \u201cDynamization\u201d column, use the dropdown to\u00a0select Script. This will open a script editor to allow for control of the desired property.<\/p>\n\n\n\n

\"Siemens<\/figure>\n\n\n\n
\"\"<\/figure>\n\n\n\n

The variable \u201cvalue\u201d refers to the state of the property scripting for. For example, if I created a script that resulted in \u201cvalue = 5\u201d for width, the\u00a0component\u00a0would\u00a0display with\u00a0a width of five pixels.\u00a0Additional\u00a0code should always be written between the declaration of the \u201cvalue\u201d variable and the return.\u00a0\u00a0<\/p>\n\n\n\n

Script Tools <\/h2>\n\n\n\n

Siemens offers a few helpful tools as part of the script editor to make it easier to create working code. Some of these tools exist as buttons on the script editor, and some are built-in features, such as:\u00a0<\/p>\n\n\n\n