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  1. OMG Issue

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

  • Key: XTCE13-125
  • Status: open  
  • Source: Space Applications Services ( Nicolae Mihalache)
  • Summary:

    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.

  • Reported: XTCE 1.2 — Thu, 22 Apr 2021 08:17 GMT
  • Updated: Wed, 21 Sep 2022 18:57 GMT