What's New?

This version of UniLogic, released in September 2026, extends the UniLogic AI Prompt Generator Wizard with Image Generation for HMI widgets. In addition to generating Structured Text (ST) logic, the wizard now produces AI image prompts for your HMI widgets - organizing your visual requirements and preparing them for AI-assisted image generation, without your needing to write the prompt text yourself.

This version also upgrades the UniStream security stack to OpenSSL 3.5.5 and OpenSSH 9.9p2, strengthening the PLC's security and enforcing modern encryption standards.

TLS 1.2 and TLS 1.3 are supported, while obsolete TLS versions and legacy cryptographic algorithms are no longer accepted.

No action is required for UniLogic, UniApps, or Cloud connectivity. Third-party clients (OPC UA, MQTT, BACnet, REST, SFTP/FTP) using outdated security protocols may require configuration updates.

UniLogic 1.43.XX includes the additional features and bug fixes listed below to streamline your programming power.

New Functions

AI Image Widget	Image Generation for HMI Widgets The AI Prompt Generator now supports generating SVG images for HMI widgets, in addition to its existing Structured Text generation capabilities. Selecting Generate Image for Widget on the Project Identity screen opens a new four-step wizard that collects your image requirements — widget type, visual description, styling, and canvas size — and exports a validated Markdown (.md) prompt file. Supported widget types: Image, Binary Image, List Of Images, and Range Of Images. Upload the exported .md file (along with any reference images) to your AI assistant. The assistant presents concept previews to choose from, then returns a downloadable AI Image Widget package (.uisvgpkg), which imports directly via the widget's Import Package property or by dragging the file onto the HMI screen.
VNC	Hardware-accelerated VNC Advanced Video Codec (H.264)  H.264 (Advanced Video Codec) support for VNC sessions on Built-in (US5, US7, US10, US15), PLC (USC) series controllers, and USL (USL5, USL7, USL10, USL-215) displays. The H.264 offloads the video stream to the hardware encoder/decoder for smoother, faster VNC sessions. Not supported on Modular (USP) controllers.   Force H264 Encoding: (Built-in and PLC (USC) series controllers as VNC Server) - set in UniLogic -> Controller Model -> Hardware Configuration, or on-device at UniApps -> Network -> VNC Server. When enabled, the server accepts only H.264 clients - the standard RealVNC Viewer will fail to connect; TigerVNC client supports H.264 but may need to be configured first. Force H264 Decoding:  (Built-in, PLC (USC) series controllers, and USL (USL5/USL7/USL10) displays as VNC Client) - set in UniLogic -> PLC Communications -> Protocols -> VNC Clients, or on-device at UniApps -> Network -> VNC Client. These models have no automatic fallback - clear the checkbox to connect to a server that doesn't use H.264. USL-215 (Display): H.264 decoding is automatic, with fallback to another encoding if the server doesn't support H.264. No configuration required. Server-side up-scaling has been removed: the VNC Server now always transmits the panel's own resolution: - Built-in US5/US7: 800x480 - Built-in US10:1024x600 - Built-in US15:1366x768 - PLC/USC: the Panel Resolution configured in UniLogic. If the display on the viewer side isn't the size you want, adjust the scaling from the VNC Client instead.
IO-Link	UniLogic now enables cyclic raw process-data exchange with generic IO-Link devices, which allow the use of IO-Link ver. 1.0 devices. When automatic process-data mapping is unavailable, or when direct access to the device's raw IO-Link data is needed, select Advanced in the device's Properties window and manually set the Input Size and Output Size (0-32 bytes). UniLogic exposes the configured data as raw buffers in the automatically generated IO-Link device structure; the application is responsible for interpreting the data according to the device manufacturer's process data definition.
OPC-UA	The UniStream OPC UA server has been upgraded. As part of this update: Authentication is no longer exclusive: Named users (Username/Password) are now always active when defined. A new Allow Anonymous access checkbox lets anonymous connections work alongside named users at the same time. User roles simplified: Users are now assigned one of two roles - Operator or Observer - replacing the previous Admin/User groups. A Role is required for every user before the project can be downloaded. Address Space access levels updated: The "Admin Group Read/Write" access level has been renamed to "Operators Read/Write", granting write access to Operator-role users (Observers stay read-only). Plain Read/Write grants write access to any named user. Available options depend on Allow Anonymous access: Read, Read/Write, and Operators Read/Write when unchecked; just Read and Read/Write when checked. HotRunner Address Space: Added a Show bit to ClassifiedActiveError entries to allow users to hide or publish selected ActiveErrors from the OPC UA client.
Structured Text	Structured Text (ST) now offers expanded functionality, including access to Ladder Toolbox functions and improved online monitoring: Ladder Toolbox Functions in Structured Text You can now call selected Ladder Toolbox functions directly from ST, enabling you to use existing Ladder functionality without switching to a Ladder function. This adds support for: Data Tables: FIFO and LIFO operations, Indexed Data Table (DTI) row and column operations, asynchronous DTI row insertion, and SD/CSV/Recipe data-transfer functions. PID: Run and autotune functions, including running and resetting autotune, pausing or forcing integral and derivative calculations, and saving or loading autotune data. The functions use the same parameters and data structures as their Ladder counterparts and support ST editor features such as autocomplete and parameter hints. Monitor a Specific Function Call from Structured Text You can now navigate to and monitor a specific Function call from Structured Text (ST) - matching the existing Ladder capability. Calls to user-defined Functions in the ST editor are clickable; click (or right-click) a call for: Navigate to Function: Opens the called Function in the editor. Monitor (Online only): Opens the called Function in Online Monitor mode, showing its FunctionIn, FunctionOut, and Local values for that specific call.
Redfish	UniStream Redfish support has been expanded with new authentication, certificate management, and remote device management capabilities. Account Service:  Centralized user account management with role-based access control (Administrator, Operator, ReadOnly), configurable password policy, and automatic account lockout after repeated failed login attempts. Session Service:  Token-based (X-Auth-Token) authentication, allowing clients to log in once and reuse a session token instead of sending credentials with every request. Session timeout and concurrent session limits are configurable. Certificate management: View the active HTTPS certificate, generate a Certificate Signing Request (CSR), or replace the server certificate - all directly through the Redfish API. Manager resource: A Manager resource can now be defined under Redfish Objects, representing the UniStream PLC management controller. It exposes basic device identity (Model, Manufacturer) and a remote reboot action. One or more Chassis resources can be linked to the Manager directly; Chassis and CDU resources can each also link back to the Manager via their own Managed By field. Service Root fields: New Product, Vendor, and UUID fields, configurable in Solution Explorer and returned in the Redfish Service Root response. Chassis fields and links:  New optional PowerState, UUID, and Version fields. Chassis can now be linked to one or more CoolingUnits directly in Redfish Space. CoolingUnit (CDU) fields and links:  New optional UUID field. CoolingUnits can now be linked to a Chassis directly in Redfish Space. Coolant reporting: CoolingUnits and Coolant Connectors linked to a CoolingLoop now automatically report CoolantType, Density, and Specific Heat from that loop. Note: The Filter resource's field ServiceDate has been renamed to ServicedDate. Update any client code that references the old field name.

 

Additional Functions and Enhancements

• Redesigned the Management: UniStream Firmware Versions window for improved clarity, organizing firmware into Updates, Baseline, Previous Versions, and Beta tabs, with icon-based status indicators.

• UniLogic, PLC Communications: Improved network security by disabling outdated TLS 1.0 and TLS 1.1 protocols on the Redfish service (port 443) and the UniLogic communication service (port 8001).

• Modbus: Performance improvement in Modbus serial setups containing multiple UniStream units.

• UniApps: When a 'Version Mismatch' occurs during a PLC BIN upgrade, the PLC now automatically clears the UAC settings. This prevents users from being locked out of the screen following a BIN upgrade.

• When upgrading a USBF prepared from UniLogic that contains both a BIN and an APP upgrade, only a single screen press is now required to complete the entire process.

• Built-in tags in UniLogic (including System tags, I/O tags, and Reserved UDT members) have been renamed to comply with Structured Text (ST) variable naming rules. Tag names now contain only letters (A-Z, a-z), digits (0-9), and underscores, and start with a letter or underscore.
  Note: Existing projects continue to work without requiring manual updates to Ladder Logic or tag references. 

• UniApps: Added support for displaying and editing Structured Text Time and Date Data types using their standard ST representation formats.

• AI Prompt Generator: Reduced the minimum word count for the Purpose field to 3 words and for other validated text fields to 5 words.

Bugs fixed in this patch

• Online Mode:
  - In certain cases, opening a specific ST function in Online Mode could terminate the online session.
  - An oversized registration request could cause the PLC Online service to crash, resulting in a communication error and disconnection from the PLC.

• LF: Within Range: Compilation errors occurred when the output was linked to a bit within an array or within a struct.

• Firmware Download: Firmware downloads could fail when a system proxy is required.

• Firmware Manager: The Firmware Manager could appear empty when UniLogic was run as Administrator.

• Alarms: Deleting multiple alarm conditions, alarms, or alarm groups could fail with a 'Could not find stored procedure' error.

• Exporting global tags from UniLogic could fail.

• Structured Text (ST):
  - 'Division by 0 is illegal' was incorrectly reported for valid fractional constant divisors.
  - In certain cases, FOR Loops with constant ranges could access array elements outside the array's declared bounds without generating a compile error.
  - Function parameters with names that differ only by spaces ' ' and underscores '_' could cause compilation errors.
  - Autocomplete member selection could replace text on the wrong line.
  - Using Ctrl+Z after an autocomplete action could cause UniLogic to crash.
  - Typing and deleting characters in function calls could cause the editor to freeze for approximately 30 seconds.
  - Identifier autocomplete rebuilt the full list of completion items on every keystroke, causing performance degradation when typing or deleting text.
  - Call Function tag assignments were lost when dragging or copying imported functions.
  - UDINT_TO_REAL is now supported as a Structured Text conversion function.

• OPC-UA:
  - BrowseName used an incorrect namespace for standard-defined nodes.
  - ActiveErrors nodes were displayed with a fixed array size instead of reflecting the actual number of active errors.

• HMI: Alarm Status Viewer: Cleared alarms were displayed as active after acknowledgment.

• UniApps: Time & Date: 'Sync Now' and periodic time synchronization did not apply timezone or DST changes until the PLC was rebooted.

• HE: Bitmap Grid: Defining more than 8 Bitmap Values on a Bitmap Grid widget, caused cells mapped to values beyond the 8th to render as white instead of the intended color. The widget now enforces a maximum of 8 Bitmap Values.

• WebServer: Unable to modify Data Table data.

• Web Pages: Leaving a Data Table unlinked or linking it to a non-existent table could cause UniLogic to crash.

• Timers: Legacy Ladder TON, TOFF, and TA timers with Preset = 0 could remain permanently active or inactive.

• Modbus TCP: Could stop working after updating the same application while preserving the Panel IP.

• EtherCAT:
  - I/O Alias Names could disappear after opening a project created in an earlier UniLogic version.
  - E5-S drive 'Is Connected' bit could fail to clear when the drive was disconnected.

• Tag Editor: Could not add more than one ENUM instance without reopening the dialog.

• HMI Message Box: 'Set Value' action could fail for tag-to-tag assignments and stopped remaining actions from running.

• AI Prompt Generator: Functions containing arrays were exported in an incorrect format.

• Modbus: In certain cases, adding UAC-02RS2/UAC-02RSC modules could create duplicate Modbus Master configuration names for the secondary COM port, resulting in compilation errors.

• HMI / WebServer: Copying, pasting, duplicating, or undoing/redoing elements linked to aliased operands could cause the alias link to be lost.

• In certain cases, High-Speed Input Counters initialize to a value other than 0 after PLC startup.

• UID-0808THS: PTO calculated current position incorrectly when a halt or stop was requested.

• UAC: 'Auto Logoff and return to home screen' did not operate correctly when VNC sessions were connected or disconnected.

• BACnet/IP: Communication over IPv6 failed when IPv6 was enabled from UniApps after project download.

• LF Get List Member: Compilation error when the Index (B) or Assignment (C) operand of the function was linked to a member of a Struct or Array.

• HMI: UniLogic could crash on startup if a Properties Window had been undocked when UniLogic was last closed.

• UniApps: In certain cases, the CPU MAC address was not displayed in the IP Config tab.

• PDF Viewer: HMI becomes unresponsive when navigating between screens containing PDF Viewer widgets, followed by an automatic HMI application restart.

• Remote I/O: Resolved an issue where expansion-module outputs could energize unexpectedly, mirroring the state of inputs at the corresponding index, even when the application did not command the outputs.

• In certain cases, DHCP IP assignment could cause a 'Too Many Registrations Detected' message to appear and the HMI to freeze.

• Downgrading to a UniLogic version earlier than 1.41 could cause the HMI to enter a crash loop if the project contained licenses for features not supported by the target version. 

• HMI: Resolved an issue where renaming a tag by replacing spaces with underscores (such as during an upgrade) could cause the HMI compile process  to drop the associated Local Action from the compiled application.

• Modular PLCs: Adding more than one RS232 module could cause compilation errors.