I currently have a use case where I have a need of adding a new Operational Mode into my vision state machine. This new operational mode cant be accessed directly by the client, instead it is accessed by the actions of the user interface (aka frontend). In section 8.3.9 Adding an operation mode we find the following notes:

2.b. defines a SelectModeVendor method to trigger a transition into a desired starting state of this SubStateMachine.
2.c. binds the SelectModeVendor method as additional HasCause to the method-triggered transition from the Preoperational state to the Operational state, i.e., T141 in Table 84 (according to OPC 10000-5 B.4.18, adding causes to a transition

Since this new operational mode should not be accessed via the client and only if there is user interaction there is no need for me to provide a SelectModeVendor method. What should be the correct behavior here ? Is it really require that the method is define in order to add a new mode of operation? Additionally, in the automatic mode defined by the standard the "SelectModeAutomatic" method is define as optional and even if it is define in the type it does not need to be instantiated if what you need is to have just automatic transitions.

The way I see it there are two possible solutions:

• Mandate that you do need a method but it can be optional same as in Automatic Mode.
• Change points 2.b and 2.c slightly as to hint that adding a SelectModeVendor method might not be needed depending on the use case.