Apparatus and methods regarding a processing system operable to implement an arbiter. The arbiter receives commands from non-prioritized and prioritized actors, and repeatedly issues an earliest received, non-issued command received from the non-prioritized actor. Execution of an immediately preceding issued command is completed or terminated by a sending actor of the immediately preceding issued command before a subsequent earliest received, non-issued command is issued. The arbiter also issues a command received from the prioritized actor upon receipt of the command received from the prioritized actor. Issuance of the command received from the prioritized actor interrupts issuance and execution of a command received from the non-prioritized actor. The commands from the non-prioritized and prioritized actors are issued to equipment controllers operable to control equipment of a well construction system.