Downloads

1.37 (Feb. 19, 2026)

Filename: tcpdu_1_37.bin (1.3 MB)

Fixed

• LTE modem support:
  • Support for longer SMS messages with commands sent to the tcPDU.
  • LTE network connection.
  • Support for an access code in SMS messages.

1.36 (Feb. 12, 2026)

Filename: tcpdu_1_36.bin (1.3 MB)

NOTE: After updating the firmware, check the HTTP Client settings (new settings options: Request method, Headers, Request body). For the HTTP Client, double-check the tab (e.g., navigate to a different tab and return) to display the current values ​​for these options. You can then change the Headers field to blank to ensure the function works according to the previous settings.

Added

• New authentication system.
  • Login on the web interface is integrated with Basic Authentication. Previously, there were two login forms — one handled by the browser using Basic Authentication and another on the Login page.
  • Basic Authentication is enabled by default.
  • With default settings, i.e. with Basic Authentication enabled, access credentials are properly protected. An issue was removed where a user could read admin credentials.
    Please note that the admin/user separation previously served only a visual purpose and did not provide real access control. It now fulfills both roles — providing access to a simplified view for user and a full configuration view for admin, with proper separation of access rights to resources.
• Extension of the HTTP client functionality with the ability to select the request method: POST, PUT, PATCH (in addition to GET), define headers, and define the request body (text only, not binary).
• (LTE version only) CLIP function — reacting to an incoming call from a trusted number by switching the OUT output or a VAR variable.
• UI:
  • Automatic selection of the first free position when using the clone/copy options for Events and Schedule entries (it is still possible to manually select a different, later position).
  • Ability to download and install a new firmware version after checking availability, directly from the web interface.
  • Device name (hostname) displayed as a tooltip on the link to the home page (the LK4 label on the top bar).
  • Warning about SMS text length limitations.

Changed

• Extension of the MQTT topic prefix length in the MQTT client from 14 to 32 characters.
• UI:
  • Inclusion in the settings migration function of: access credentials (usernames and passwords), I²C readout names, CLIP function options in the LTE modem, and HTTP client options (method, headers, body).
  • Separation of the MAC address from network settings in the settings migration function. This simplifies cloning settings across multiple devices.
  • The settings migration function updates the interface state during import, e.g. changes the interface language.
  • Removal of delays between saving consecutive parameters in the settings migration function, resulting in a significantly shorter import time.
  • Validation of the E-mail form now allows setting an empty password and username.
  • Removal of the automatic login feature due to incompatibility with the new authentication system.

Fixed

• SNMP Trap message structure (incorrect fixed OID).
• MQTT ID is now derived from the original MAC address, not the configured one.
• Extension of the MQTT ID length from 6 to 8 characters.
• Setting the value 31 for minutes and seconds in the Scheduler.
• Execution times of Scheduler actions. Previously, executions could be skipped or duplicated.
• Returning ping values from the device on timeout and displaying the appropriate state in the UI (65535 value and Timed out message) in the Watchdog function.
• UI:
  • Handling of a restart limit equal to 0 in the Watchdog function — allows the function to run indefinitely.
  • Handling of file versions in the settings migration function.
    Importing settings from newer software into older software is not recommended. It is recommended to use the same software version or migrate from older to newer.
  • Parsing and formatting requests sent from the web interface to the device to avoid exceeding the request length limit (approx. 1800 characters).
  • Setting and displaying the device name (hostname) in the page title shortly after visiting the page (the name is already set on the login page).

1.30 (March 12, 2025)

Filename: tcpdu_1_30.bin (1.4 MB)

Fixed

• SMS reboot command in LTE version.
• Function of keeping the state after restart for OUT outputs.

1.28 (Feb. 14, 2025)

Filename: tcpdu_1_28.bin (1.4 MB)

Fixed

• Removing authUser entries, i.e. users with permissions only to control outputs.

1.27 (Jan. 3, 2025)

Filename: tcpdu_1_27.bin (1.4 MB)

Added

• RESTART action to the Events function (like in the Scheduler, used to restart the device).

Changed

• UI/UX improvements:
  • HTTP client URL validation allows using :`! in the path section.
  • Restart limit validation in Watchdog allows setting the value to 0 (no limit).
  • Ability to change the DS name in the Sensors tab.
  • Sensors page layout using tabs (presentation of extended 1-Wire and I2C sections).

Fixed

• The operation of the user list for controlling OUT outputs. In the Access tab, you can add users who can control OUT outputs using the commands /api/v1/save/?outX=Y and /api/v1/save/?out=outX. Please note that the function only works when Basic Authentication is enabled and is not used to sign in to the device page.

1.25 (Nov. 20, 2024)

Filename: tcpdu_1_25.bin (1.4 MB)

Added

• Header Access-Control-Allow-Origin: * for HTTP responses with dynamic values ​​(/api/v1/read/status/).
• Dark mode with a switch on the top bar.
• Ability to automatically sign in as a user with a special link /#/?signIn=user when the Automatic sign in function is enabled.

Changed

• Multiple UI/UX improvements: unified tables styling, Modbus page layout, unified placement of icons on buttons, increased default size of modem console and added the prefix $ for user input, changed the backup filename to include more information, fixed some error messages, removed limit for setting on/off delay (was available only for OUT/VAR), fixed saving Network form (when changing from DHCP to static), added verification after updating FW on the page (might alert if the page is not available after update, so can update again in UI), fixed refreshing PM and CO2 values in I2C and 1-Wire page.

Fixed

• Mapping of reactive and apparent power in Power and Energy (they were swapped).
• Require Basic Authentication (when enabled) for all resources (/api/v1/save/ and /api/v1/read/).
• Setting entries 10-50 in the Scheduler.

1.23 (Nov. 15, 2024)

Filename: tcpdu_1_23.bin (1.4 MB)

Fixed

• Attempt to send an email when there is no network access no longer leads to restarting the device.

1.22 (June 20, 2024)

Filename: tcpdu_1_22.bin (1.4 MB)

Changed

• Removed mqttModem and httpModem options - LK automatically manages network interface priorities (Ethernet and LTE).

Fixed

• Writing and reading diffNameX options.
• Action MQTT in the Events function. Additionally, for the MQTT CONNECTION input in the first condition, the MQTT action has no effect.
• Action SMS in the Events function (sending SMS with the action variant when the condition is no longer met).
• Receiving empty MQTT messages - now they are ignored.
• Data migration function - when uploading data from an older SW version, it only applies corrections when needed (e.g. setting event with a value for the mode option).
• Presentation of data in tables, e.g. events and schedule. The indicated row is highlighted to make it easier to read the values ​​set in it.

1.19 (May 16, 2024)

Filename: tcpdu_1_19.bin (1.4 MB)

Added

• TLS option in E-mail function, allows you to choose without encryption, StartTLS and SSL/TLS. Previously, only StartTLS was supported.

Changed

• Number of WiFi connection attempts when the device is turned on or after disconnection from 2 to 1000 (approximately 40 minutes)

Fixed

• SNMP operation - fixed problems with reloading settings and their incorrect application.
• Saving APN and other options on the LTE Modem page.

1.16 (Dec. 13, 2023)

Filename: tcpdu_1_16.bin (1.4 MB)

Added

• Mode option for Action in Events. It allows you to specify when the event action will be performed - when the condition begins to be met, when it stops being met, or both (default behavior, compatible with previous versions of the software).
• (only for tcPDU with LTE) LTE modem support, Internet connection via PPP and SMS command support. Three standard commands as in LK3: reboot, on, off, and the ability to send commands as in HTTP queries after using the cmd prefix, e.g. 1234:cmd:out=out1.
• Email configuration for the Watchdog function and events allows you to set different addresses, topics and message contents for notifications. In the case of events, two variants are supported: when the event condition is met and when it ceases.

Changed

• Address fields in the HTTP client extended with a dedicated field for cyclic sending and four options with variants for sending when the event condition is met and when it ceases.

Fixed

• Adding events at position above 10.
• IP, date and time in variables (reading codes) for HTTP, OLED, SMS client.
• Basic and Digest Authentication support in HTTP client.
• Port in HTTP client.
• MQTT topics on iDValue1 and iDValue2.
• Memory leak when authorization is enabled on the HTTP server.
• Operating on older versions of tcPDU (HW 1.0).
• Display the modem options page.
• Saving APN and other options on the modem page.

1.10b (July 18, 2023)

Filename: tcpdu_1_10b.bin (1.3 MB)

Added

• Watchdog.
• SNMP.
• Discovery - can be detected with LKTools just like LK.
• HTTP Client.
• Offsets for 1-Wire sensors DS18B20.

Fixed

• Reset time (time of return) for outputs.
• Displaying power and energy.
• Selecting data for sending in MQTT Client tab.
• Saving HTTP Client settings.