Interface and integration method for external control of the drilling control system

A method of controlling a borehole drilling process comprising a first set of operations and a second set of operations, the method comprising: generating and outputting at least one control signal by a drilling control system for controlling at least one control parameter associated with the first set of operations; and, subsequent to an indication that the first set of operations is complete, outputting at least one control signal received from an external system at the drilling control system for controlling at least one control parameter associated with the second set of operations. A control system is also claimed. The first operations maybe non-drilling based such as making up pipe or BHA, the second operations maybe drilling based such as drilling or circulating cuttings. The method maybe based on the status of the slips may employ logic and may operate within safety signals as the parameters.