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Firmware for GLT400 download

Software License Agreement

It is required to review the following license agreement before the software is downloaded. We will be deemed that the customer has to agree to the terms and conditions of the license agreement when the software had been downloaded by the customer. Please note that it is not possible to download or use the software if the customer does not agree to it.

Downloading Files

Ver.1.05 (Latest version)

Date of updated9 Nov, 2022
Supported ProductsGLT400
Downloading filesSoftwareGLT400_FU(v105).zip (2,899KB)

Revision History


  1. Fixed the problem that the error value of reading input data (Function code 4) is incorrect in Modbus/TCP.    


  1. Fixed the problem that the response value of Function code 3 and 5 becomes an unintended value in Modbus/TCP.              
  2. Fixed the problem that waveforms update interval becomes slower when waveforms are displayed by the WEB sever function and tabs are not active.
    Fixed the problem that Email cannot be sent correctly when using the mail sending function via a wireless LAN connection with B-568 (GL Wireless LAN unit) or a slow communication line.
  3. Enhanced communication in the event of unauthorized access to the WEB server function such as DoS attacks when the GLT400 is connected to an externally accessible Internet connection.
  4. Fixed the problem that connection becomes unstable after many connections overlap on a line with slow network speeds.


  1. Fixed the problem that the GLT400 is not recognized by the PC in rare case when the GLT400 is connected to the PC with a USB cable and started in USB drive mode.


  1. Supported that annotation information on the channel where the alarm occurred is included in the body of the e-mail in the alarm e-mail notification of the e-mail transmission function.
  2. Enhanced communication processing with the GL840 when the GLT400 is connected as a cordless extension unit of the GL840.


  1. Initial version