Command and Control
Commanding to a satellite, payload or piece of ground equipment may be accomplished via automated command procedures, task scheduling and manual commanding. The execution flow of a command is shown in the block diagram below.

The Command Process Summarized
 
Prior to a command being released for execution, a number of pre-checks may be performed. For any mission, the specific checks and their default enable/disable state are configurable, and examples of some types of pre-checks are Time Tag or Pacing, Critical and Forbidden, and Argument Limit Checking. With acceptable pre-check results the execution of the command is accomplished in either immediate or two-step mode. When sent in immediate mode, the command is expected to execute on board the spacecraft upon reception. In two-step mode, the command is sent to a load register. Once this has been confirmed, an execute command is sent either automatically or upon user confirmation. Validation is done to ensure the command decoder unit received the command. InControl performs validation utilizing Command Echo Bits, Execution Flag, or Command Counter algorithms. And finally, after a command is validated, post-checks are performed. The included post-checks and the order in which the checks are performed are configurable. Standard checks include setting command-driven status for items that do not have telemetered status, or parameter verification against a set of expected values. Alarm management may be done in conjunction with the pre-check alarm management to re-enable alarm processing that was disabled as a result of the command sent.