Here the relevant text of the current Spec.:
• The mandatory Variable DeviceConfigurationDisabled indicates whether configuration changes of the connected IO-Link Device (Device Object) are allowed via OPC UA. If set to “True”, nearly all configuration settings become read-only and cannot be changed via OPC UA anymore. The Variable setting is vendor-specific, including whether it can be changed via OPC UA. For example, if a fieldbus is currently active on the IO-Link Master, a server might set this Variable to “True” on all its ports.
That includes in detail following rules:
o For the IO-Link Device connected to the IO-Link Port (Device Object) all Parameters become read-only.
o For the IO-Link Device connected to the IO-Link Port (Device Object) all Methods defined in the IOLinkDeviceType except ReadISDU become not executable.
o For the IO-Link Device connected to the IO-Link Port (Device Object) all Methods created based on the IODD become not executable unless the Methods only trigger the reading of ISDUs.
The Method ResetStatistics on the IO-Link Port and ResetStatisticsOnAllPorts on the IO-Link Master shall still be executable.
There is no direct relation between the DeviceConfigurationDisabled Variable and the Lock Object on the IOLinkDeviceType. The Lock Object prevents different OPC UA Clients to configure the IO-Link Device at the same time whereas the DeviceConfigurationDisabled Variable indicates that the IO-Link Master is in a state that does not allow the IO-Link Device to be configured by any OPC UA Client. When the DeviceConfigurationDisabled Variable is set to “True” Servers may prevent the usage of the Lock Object for all Clients