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Entry type: Product note Entry ID: 109772048, Entry date: 10/09/2019

Firmware update V2.1.7 for LOGO! CMR2020 (6GK7142-7BX00-0AX0) and LOGO! CMR2040 (6GK7142-7EX00-0AX0)

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The new firmware V2.1.7 for the LOGO! CMR2020 and LOGO! CMR2040 modules has been released and is now available for download free of charge. Firmware version V2.1.7 is the successor to version V2.1.5 and contains important product improvements.

Upgrading with a free firmware update is recommended. In particular for systems that update the module time with a LOGO! CMR2040 via GPS. Due to the overflow of a counter in the GPS receiver (GPS rollover), from 2 November 2019 at 23:59:42 UTC defective GPS time synchronization with older firmware versions could occur.

The LOGO! CMR with firmware V1.x and V2.x that are already in use can be updated via the Web Based Management (WBM).

The LOGO! CMR2020 (6GK7142-7BX00-0AX0) and LOGO! CMR2040 (6GK7142-7EX00-0AX0) modules are scheduled to be delivered with the new firmware V2.1.7 as soon as possible.

1.    Security information

This update contains safety-relevant changes which enhance robustness against possible attacks. We therefore recommend that you update the firmware.

2.    Product enhancements

LOGO! CMR2040:

Time synchronization via GPS: Concerns all systems that update the module time with a LOGO! CMR2040 via GPS. Due to the overflow of a counter in the GPS receiver (GPS rollover), from 2 November 2019 at 23:59:42 UTC defective GPS time synchronization with older firmware versions could occur. An update to firmware V2.1.7 is therefore absolutely recommended for this application.

This does not apply to the CMR2020.

Communication via VPN: The data throughput via the VPN connection of the LOGO! CMR2040 characteristic has been increased.  

SMS transmission: The sporadic behavior that following the upgrade of the firmware from V1.x to V2.x no SMS can be sent, has been rectified.


 LOGO! CMR2020 and LOGO! CMR 2040:

SMS user group: The behavior that SMS have been erroneously sent to user groups 1 and 2 instead of user groups 9 and 10 has been rectified. 

Name resolution (DNS): The name resolution for time synchronization via NTP, DynDNS and email has been improved. 


2. Notes on installation/commissioning

  • The LOGO! CMR is configured via the WBM of the module.
    With factory settings, the IP address is or
    The login data are initial:
    Login: admin 
    password: admin


  • If the "DynDNS" provider is enabled in V2.0.12, the following must be noted when updating firmware V2.0.12 to firmware V2.1.x with DynDNS enabled:
    1.    DynDNS must be disabled in the WBM --- this change in the configuration causes the LOGO! CMR to freeze.
    2.    The LOGO! CMR must be restarted. After restarting, DynDNS is disabled.
    3.    The firmware update V2.1.x can be installed and activated (see item below).
    4.    After successfully updating, DynDNS can be activated in the WBM once again.

  • The firmware is updated via the WBM of the LOGO! CMR.

Navigate to the "Maintenance" entry - "Firmware" tab.  The firmware update can be loaded using the "Browse" button there.

Note: It is not possible to downgrade the firmware to an older version.

For more information, refer to the LOGO! CMR Manual


4. Notes on configuration


  • Configuration via the WBM of the module. All standard browsers can be used for the configuration. We recommend always using the most recent browser version. The LOGO! CMR is released with:
    • Internet Explorer Version 11
    • Microsoft Edge version 44.17763.1.0
    • Firefox Quantum version 65.0
    • Google Chrome Version 72.0
    • Apple Safari V9
  •  All configurations that were created with a previous firmware version can also still be used with firmware V2.1.7. This means the saved configuration is updated to the new version when upgrading the firmware. Old settings are retained, and new functions are preset with default values. Configurations (*.cfg files) that were created with previous firmware versions can also be downloaded to a LOGO! CMR with firmware V2.1.7.


5. Note on operation


  • In very rare cases an error may occur in the mobile wireless module of the module. If the CMR detects this state, it automatically initiates a restart. The outputs are de-energized for a brief period of time during this restart.
  • For remote access directly via the IP address per HTTPS (not via VPN tunnel) of the LOGO! CMR, browsers that permit communication via a single connection must be used. Mozilla Firefox is recommended.
  • Reconfiguration is not possible during the dial-in process into the mobile wireless and data network. A corresponding error message is displayed. 


6. Hardware version  

  • The two LOGO! CMRs are delivered with hardware product version 2.

7.    Additional information

Delivery release for LOGO! CMR

LOGO! CMR Manual


Application examples

Security information
In order to protect technical infrastructures, systems, machines and networks against cyber threats, it is necessary to implement – and continuously maintain – a holistic, state-of-the-art IT security concept. Siemens’ products and solutions constitute one element of such a concept. For more information about cyber security, please visit
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