XTCE13 — Access to command arguments in transmission constraints and command verifiers

Sometimes the constraints and/or verifies associated to a command may depend on the value of the arguments of the command sent. For example setting a thermostat to a certain setpoint may have a constraint which will only allow a given setpoint in a specific operational mode.
A verifier can compare the setpoint sent as command argument with the setpoint known in the spacecraft and received as a TM parameter.

To achieve this, arguments references should be allowed in the definition of the constraints/verifiers.

In practice:

• TransmissionConstraintType should extend the ArgumentMatchCriteriaType (instead of MatchCriteriaType)
• CommandVerifierType should allow elements of type ArgumentInputAlgorithmType , ArgumentBooleanExpressionType and ArgumentComparisonType (instead of the non argument variety)

All the Argument* types are superset of the corresponding non-argument types so by doing this change, the schema will be backward compatible.

Note: a similar request could be argued for ParametrToSetType to allow setting a parameter to a value computed based on the user defined argument of the command. However since there is no ArgumentMathOperationType, no easy solution can be immediately seen without adding extra types.