SPDM v0.1 (Synarius Parameter Data Model)¶

Status: Draft mini-specification

Scope¶

SPDM v0.1 defines a canonical, XML-based parameter model for Synarius that is:

strongly typed
semantically rich
suitable for simulation and code generation
variant-capable
designed for loss-minimizing import/export with DCM2, CDFX, and PAR

1. Conceptual Model¶

Parameter¶

A uniquely identified configuration/calibration item.

Required: id, typeRef
Optional: path, unitRef, quantity, defaultValue, constraints, metadata

ParameterSet¶

A versionable container of concrete parameter values.

Supports inheritance via baseSetRef
Contains values for parameter IDs
May carry variant-specific overrides

ParameterValue¶

Typed assignment for one parameter in a set.

BaseValue: unconditional
Override: conditional via variant condition
Can carry coded and physical form where needed

Type system¶

Scalar: int, float, bool, string
Enum: named literals, optional coded representation
Array: 1D..nD values
Curve/Table/Map: axis-based values
Struct: named fields with typed values

Units and quantities¶

Unit is referenced via unitRef
Physical quantity is optional metadata (example: torque)
Conversion/coding metadata can be carried in metadata or extensions

Constraints¶

Numeric ranges (min/max; hard/soft semantics)
Validity ranges
Enum domain restrictions
Recursive constraints for arrays/structs

Variants¶

Conditions are named expressions in VariantModel
Override entries reference condition IDs
Resolution is deterministic by priority
Priority ties among active overrides are invalid

Defaults vs actual values¶

defaultValue lives in ParameterDefinition
actual values live in ParameterSet
if no actual value exists, fallback is defaultValue

Metadata¶

Namespaced metadata may appear on package, parameter, set, and value levels. Typical content:

source origin descriptors
author/timestamp/comment
release/process flags

2. Design Principles¶

Canonical model first: SPDM is normative internally.
Semantics/storage separation: model semantics are independent from XML carrier details.
Import information preservation: unmapped source details must be retained in metadata/extensions.
Explicit representation: coded and physical values may coexist.
Safe extensibility: versioned schema + namespace extensions + round-trip of unknown extensions.

3. XML Representation¶

Root¶

Element: spdm:ParameterPackage
Namespace: urn:synarius:spdm:0.1
Required attributes: schemaVersion, packageId, createdAt

Normative top-level order¶

TypeDefinitions
UnitDefinitions
ParameterDefinitions
VariantModel
ParameterSets
Extensions (optional)

ParameterDefinition shape¶

Required attributes: id, typeRef
Optional attributes: unitRef, quantity, path
Optional children: DisplayName, Description, DefaultValue, Constraints, Metadata

Value encoding¶

ScalarValue(kind,value)
EnumValue(literal,coded?)
ArrayValue(dimensions) with Item*
CurveValue with AxisX + Values
MapValue with AxisX + AxisY + Values
StructValue with recursive FieldValue(name, Value)

Variant handling¶

VariantModel/Condition(id, expression)
Override(conditionRef, priority)
Resolve by descending priority, tie -> validation error

4. XSD (reference)¶

The following XSD is a structural baseline for SPDM v0.1. Semantic checks (cross-reference validity, dimensional consistency, override conflict checks) are implemented by application validators in addition to XSD.

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
    targetNamespace="urn:synarius:spdm:0.1"
    xmlns:spdm="urn:synarius:spdm:0.1"
    elementFormDefault="qualified"
    attributeFormDefault="unqualified">

  <xs:simpleType name="ScalarKind">
    <xs:restriction base="xs:string">
      <xs:enumeration value="int"/>
      <xs:enumeration value="float"/>
      <xs:enumeration value="bool"/>
      <xs:enumeration value="string"/>
    </xs:restriction>
  </xs:simpleType>

  <xs:complexType name="RangeType">
    <xs:attribute name="min" type="xs:double" use="optional"/>
    <xs:attribute name="max" type="xs:double" use="optional"/>
    <xs:attribute name="hard" type="xs:boolean" use="optional"/>
  </xs:complexType>

  <xs:complexType name="ScalarValueType">
    <xs:attribute name="kind" type="spdm:ScalarKind" use="required"/>
    <xs:attribute name="value" type="xs:string" use="required"/>
  </xs:complexType>

  <xs:complexType name="EnumValueType">
    <xs:attribute name="literal" type="xs:string" use="required"/>
    <xs:attribute name="coded" type="xs:string" use="optional"/>
  </xs:complexType>

  <xs:complexType name="ArrayValueType">
    <xs:sequence>
      <xs:element name="Item" type="xs:string" minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attribute name="dimensions" type="xs:string" use="required"/>
  </xs:complexType>

  <xs:complexType name="AxisType">
    <xs:sequence>
      <xs:element name="V" type="xs:double" minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attribute name="unitRef" type="xs:string" use="optional"/>
  </xs:complexType>

  <xs:complexType name="CurveValueType">
    <xs:sequence>
      <xs:element name="AxisX" type="spdm:AxisType"/>
      <xs:element name="Values">
        <xs:complexType>
          <xs:sequence>
            <xs:element name="V" type="xs:double" minOccurs="0" maxOccurs="unbounded"/>
          </xs:sequence>
        </xs:complexType>
      </xs:element>
    </xs:sequence>
  </xs:complexType>

  <xs:complexType name="MapValueType">
    <xs:sequence>
      <xs:element name="AxisX" type="spdm:AxisType"/>
      <xs:element name="AxisY" type="spdm:AxisType"/>
      <xs:element name="Values">
        <xs:complexType>
          <xs:sequence>
            <xs:element name="V" type="xs:double" minOccurs="0" maxOccurs="unbounded"/>
          </xs:sequence>
        </xs:complexType>
      </xs:element>
    </xs:sequence>
    <xs:attribute name="xSize" type="xs:positiveInteger" use="required"/>
    <xs:attribute name="ySize" type="xs:positiveInteger" use="required"/>
    <xs:attribute name="storage" type="xs:string" use="optional" default="row-major"/>
  </xs:complexType>

  <xs:complexType name="StructValueType">
    <xs:sequence>
      <xs:element name="FieldValue" minOccurs="0" maxOccurs="unbounded">
        <xs:complexType>
          <xs:sequence>
            <xs:element ref="spdm:Value"/>
          </xs:sequence>
          <xs:attribute name="name" type="xs:string" use="required"/>
        </xs:complexType>
      </xs:element>
    </xs:sequence>
  </xs:complexType>

  <xs:element name="Value">
    <xs:complexType>
      <xs:choice>
        <xs:element name="ScalarValue" type="spdm:ScalarValueType"/>
        <xs:element name="EnumValue" type="spdm:EnumValueType"/>
        <xs:element name="ArrayValue" type="spdm:ArrayValueType"/>
        <xs:element name="CurveValue" type="spdm:CurveValueType"/>
        <xs:element name="MapValue" type="spdm:MapValueType"/>
        <xs:element name="StructValue" type="spdm:StructValueType"/>
      </xs:choice>
    </xs:complexType>
  </xs:element>

  <xs:complexType name="MetadataType">
    <xs:sequence>
      <xs:element name="Entry" minOccurs="0" maxOccurs="unbounded">
        <xs:complexType mixed="true">
          <xs:attribute name="key" type="xs:string" use="required"/>
          <xs:attribute name="ns" type="xs:string" use="optional"/>
        </xs:complexType>
      </xs:element>
    </xs:sequence>
  </xs:complexType>

  <xs:complexType name="ConstraintsType">
    <xs:sequence>
      <xs:element name="Range" type="spdm:RangeType" minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
  </xs:complexType>

  <xs:complexType name="TypeDefinitionsType">
    <xs:sequence>
      <xs:element name="EnumType" minOccurs="0" maxOccurs="unbounded">
        <xs:complexType>
          <xs:sequence>
            <xs:element name="Literal" minOccurs="1" maxOccurs="unbounded">
              <xs:complexType>
                <xs:attribute name="name" type="xs:string" use="required"/>
                <xs:attribute name="coded" type="xs:string" use="optional"/>
              </xs:complexType>
            </xs:element>
          </xs:sequence>
          <xs:attribute name="id" type="xs:string" use="required"/>
        </xs:complexType>
      </xs:element>
      <xs:element name="ArrayType" minOccurs="0" maxOccurs="unbounded">
        <xs:complexType>
          <xs:attribute name="id" type="xs:string" use="required"/>
          <xs:attribute name="elementType" type="xs:string" use="required"/>
          <xs:attribute name="dimensions" type="xs:string" use="required"/>
        </xs:complexType>
      </xs:element>
      <xs:element name="MapType" minOccurs="0" maxOccurs="unbounded">
        <xs:complexType>
          <xs:attribute name="id" type="xs:string" use="required"/>
          <xs:attribute name="xType" type="xs:string" use="required"/>
          <xs:attribute name="yType" type="xs:string" use="required"/>
          <xs:attribute name="valueType" type="xs:string" use="required"/>
          <xs:attribute name="xSize" type="xs:positiveInteger" use="required"/>
          <xs:attribute name="ySize" type="xs:positiveInteger" use="required"/>
        </xs:complexType>
      </xs:element>
    </xs:sequence>
  </xs:complexType>

  <xs:complexType name="UnitDefinitionsType">
    <xs:sequence>
      <xs:element name="Unit" minOccurs="0" maxOccurs="unbounded">
        <xs:complexType>
          <xs:attribute name="id" type="xs:string" use="required"/>
          <xs:attribute name="symbol" type="xs:string" use="optional"/>
          <xs:attribute name="quantity" type="xs:string" use="optional"/>
        </xs:complexType>
      </xs:element>
    </xs:sequence>
  </xs:complexType>

  <xs:complexType name="ParameterDefinitionType">
    <xs:sequence>
      <xs:element name="DisplayName" type="xs:string" minOccurs="0"/>
      <xs:element name="Description" type="xs:string" minOccurs="0"/>
      <xs:element name="DefaultValue" minOccurs="0">
        <xs:complexType>
          <xs:sequence>
            <xs:element ref="spdm:Value"/>
          </xs:sequence>
        </xs:complexType>
      </xs:element>
      <xs:element name="Constraints" type="spdm:ConstraintsType" minOccurs="0"/>
      <xs:element name="Metadata" type="spdm:MetadataType" minOccurs="0"/>
    </xs:sequence>
    <xs:attribute name="id" type="xs:string" use="required"/>
    <xs:attribute name="typeRef" type="xs:string" use="required"/>
    <xs:attribute name="unitRef" type="xs:string" use="optional"/>
    <xs:attribute name="quantity" type="xs:string" use="optional"/>
    <xs:attribute name="path" type="xs:string" use="optional"/>
  </xs:complexType>

  <xs:complexType name="ParameterDefinitionsType">
    <xs:sequence>
      <xs:element name="ParameterDefinition" type="spdm:ParameterDefinitionType" minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
  </xs:complexType>

  <xs:complexType name="VariantModelType">
    <xs:sequence>
      <xs:element name="Condition" minOccurs="0" maxOccurs="unbounded">
        <xs:complexType>
          <xs:attribute name="id" type="xs:string" use="required"/>
          <xs:attribute name="expression" type="xs:string" use="required"/>
        </xs:complexType>
      </xs:element>
    </xs:sequence>
  </xs:complexType>

  <xs:complexType name="OverrideType">
    <xs:sequence>
      <xs:element ref="spdm:Value"/>
    </xs:sequence>
    <xs:attribute name="conditionRef" type="xs:string" use="required"/>
    <xs:attribute name="priority" type="xs:integer" use="optional"/>
  </xs:complexType>

  <xs:complexType name="ParameterValueRefType">
    <xs:sequence>
      <xs:element name="BaseValue" minOccurs="0">
        <xs:complexType>
          <xs:sequence>
            <xs:element ref="spdm:Value"/>
          </xs:sequence>
        </xs:complexType>
      </xs:element>
      <xs:element name="Override" type="spdm:OverrideType" minOccurs="0" maxOccurs="unbounded"/>
      <xs:element name="Metadata" type="spdm:MetadataType" minOccurs="0"/>
    </xs:sequence>
    <xs:attribute name="parameterId" type="xs:string" use="required"/>
  </xs:complexType>

  <xs:complexType name="ValuesType">
    <xs:sequence>
      <xs:element name="ParameterValueRef" type="spdm:ParameterValueRefType" minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
  </xs:complexType>

  <xs:complexType name="ParameterSetType">
    <xs:sequence>
      <xs:element name="Metadata" type="spdm:MetadataType" minOccurs="0"/>
      <xs:element name="Values" type="spdm:ValuesType"/>
    </xs:sequence>
    <xs:attribute name="id" type="xs:string" use="required"/>
    <xs:attribute name="baseSetRef" type="xs:string" use="optional"/>
    <xs:attribute name="priority" type="xs:integer" use="optional"/>
  </xs:complexType>

  <xs:complexType name="ParameterSetsType">
    <xs:sequence>
      <xs:element name="ParameterSet" type="spdm:ParameterSetType" minOccurs="1" maxOccurs="unbounded"/>
    </xs:sequence>
  </xs:complexType>

  <xs:complexType name="ExtensionsType">
    <xs:sequence>
      <xs:any processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
  </xs:complexType>

  <xs:element name="ParameterPackage">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="TypeDefinitions" type="spdm:TypeDefinitionsType"/>
        <xs:element name="UnitDefinitions" type="spdm:UnitDefinitionsType"/>
        <xs:element name="ParameterDefinitions" type="spdm:ParameterDefinitionsType"/>
        <xs:element name="VariantModel" type="spdm:VariantModelType"/>
        <xs:element name="ParameterSets" type="spdm:ParameterSetsType"/>
        <xs:element name="Extensions" type="spdm:ExtensionsType" minOccurs="0"/>
      </xs:sequence>
      <xs:attribute name="schemaVersion" type="xs:string" use="required"/>
      <xs:attribute name="packageId" type="xs:string" use="required"/>
      <xs:attribute name="createdAt" type="xs:dateTime" use="required"/>
    </xs:complexType>
  </xs:element>

</xs:schema>

5. Example SPDM file¶

<?xml version="1.0" encoding="UTF-8"?>
<spdm:ParameterPackage
    xmlns:spdm="urn:synarius:spdm:0.1"
    schemaVersion="0.1"
    packageId="Powertrain.Calib"
    createdAt="2026-04-02T10:30:00Z">

  <spdm:TypeDefinitions>
    <spdm:EnumType id="FuelMode_t">
      <spdm:Literal name="Eco" coded="0"/>
      <spdm:Literal name="Normal" coded="1"/>
      <spdm:Literal name="Sport" coded="2"/>
    </spdm:EnumType>
    <spdm:ArrayType id="IgnAngleCorrVec_t" elementType="float" dimensions="8"/>
    <spdm:MapType id="TorqueMap_t" xType="float" yType="float" valueType="float" xSize="4" ySize="3"/>
  </spdm:TypeDefinitions>

  <spdm:UnitDefinitions>
    <spdm:Unit id="deg" symbol="deg" quantity="Angle"/>
    <spdm:Unit id="Nm" symbol="N*m" quantity="Torque"/>
    <spdm:Unit id="rpm" symbol="1/min" quantity="RotationalSpeed"/>
    <spdm:Unit id="pct" symbol="%" quantity="Ratio"/>
  </spdm:UnitDefinitions>

  <spdm:ParameterDefinitions>
    <spdm:ParameterDefinition id="Engine.MaxTorque" typeRef="float" unitRef="Nm" quantity="Torque">
      <spdm:DefaultValue>
        <spdm:Value>
          <spdm:ScalarValue kind="float" value="300.0"/>
        </spdm:Value>
      </spdm:DefaultValue>
      <spdm:Constraints>
        <spdm:Range min="0.0" max="800.0" hard="true"/>
      </spdm:Constraints>
    </spdm:ParameterDefinition>

    <spdm:ParameterDefinition id="Ignition.CorrVector" typeRef="IgnAngleCorrVec_t" unitRef="deg"/>
    <spdm:ParameterDefinition id="Engine.TorqueMap" typeRef="TorqueMap_t" unitRef="Nm"/>
    <spdm:ParameterDefinition id="Vehicle.FuelMode" typeRef="FuelMode_t"/>
  </spdm:ParameterDefinitions>

  <spdm:VariantModel>
    <spdm:Condition id="isEU" expression="Market == 'EU'"/>
  </spdm:VariantModel>

  <spdm:ParameterSets>
    <spdm:ParameterSet id="Base" priority="0">
      <spdm:Values>
        <spdm:ParameterValueRef parameterId="Engine.MaxTorque">
          <spdm:BaseValue>
            <spdm:Value>
              <spdm:ScalarValue kind="float" value="320.0"/>
            </spdm:Value>
          </spdm:BaseValue>
        </spdm:ParameterValueRef>

        <spdm:ParameterValueRef parameterId="Ignition.CorrVector">
          <spdm:BaseValue>
            <spdm:Value>
              <spdm:ArrayValue dimensions="8">
                <spdm:Item>0.0</spdm:Item><spdm:Item>0.2</spdm:Item><spdm:Item>0.4</spdm:Item><spdm:Item>0.5</spdm:Item>
                <spdm:Item>0.5</spdm:Item><spdm:Item>0.4</spdm:Item><spdm:Item>0.2</spdm:Item><spdm:Item>0.0</spdm:Item>
              </spdm:ArrayValue>
            </spdm:Value>
          </spdm:BaseValue>
        </spdm:ParameterValueRef>

        <spdm:ParameterValueRef parameterId="Engine.TorqueMap">
          <spdm:BaseValue>
            <spdm:Value>
              <spdm:MapValue xSize="4" ySize="3" storage="row-major">
                <spdm:AxisX unitRef="rpm">
                  <spdm:V>1000</spdm:V><spdm:V>2000</spdm:V><spdm:V>3000</spdm:V><spdm:V>4000</spdm:V>
                </spdm:AxisX>
                <spdm:AxisY unitRef="pct">
                  <spdm:V>20</spdm:V><spdm:V>50</spdm:V><spdm:V>100</spdm:V>
                </spdm:AxisY>
                <spdm:Values>
                  <spdm:V>80</spdm:V><spdm:V>140</spdm:V><spdm:V>190</spdm:V><spdm:V>210</spdm:V>
                  <spdm:V>100</spdm:V><spdm:V>180</spdm:V><spdm:V>250</spdm:V><spdm:V>280</spdm:V>
                  <spdm:V>120</spdm:V><spdm:V>220</spdm:V><spdm:V>300</spdm:V><spdm:V>320</spdm:V>
                </spdm:Values>
              </spdm:MapValue>
            </spdm:Value>
          </spdm:BaseValue>
        </spdm:ParameterValueRef>

        <spdm:ParameterValueRef parameterId="Vehicle.FuelMode">
          <spdm:BaseValue>
            <spdm:Value>
              <spdm:EnumValue literal="Normal" coded="1"/>
            </spdm:Value>
          </spdm:BaseValue>
          <spdm:Override conditionRef="isEU" priority="10">
            <spdm:Value>
              <spdm:EnumValue literal="Eco" coded="0"/>
            </spdm:Value>
          </spdm:Override>
        </spdm:ParameterValueRef>
      </spdm:Values>
    </spdm:ParameterSet>
  </spdm:ParameterSets>

</spdm:ParameterPackage>

6. Mapping Considerations¶

DCM2 -> SPDM¶

Easy:

FESTWERT/FESTWERTE -> scalar/array
KENNLINIE -> curve
KENNFELD -> map/table

Ambiguous/loss-prone:

implicit typing
limited explicit unit/quantity information
tool-specific flags/comments

CDFX -> SPDM¶

Easy:

rich typed XML, including coded/physical forms
direct mapping for arrays/curves/maps/structures

Ambiguous/loss-prone:

process/QM metadata outside SPDM core

PAR -> SPDM¶

Easy:

straightforward key/value import for common scalar/vector cases

Ambiguous/loss-prone:

tool-dependent dialect differences
often incomplete units/constraints/variant semantics

Import policy:

preserve source identifiers, comments, checksums in origin metadata for round-trip traceability

7. Implementation Notes¶

Parsing strategy¶

XML parse stage
Typed IR construction
Semantic validation + normalization

Suggested internal structures¶

Package, TypeDef, UnitDef, ParameterDef, ParameterSet, Condition
ValueNode tagged union (Scalar/Enum/Array/Curve/Map/Struct)
parsed condition AST for deterministic evaluation

Versioning¶

schemaVersion follows semantic versioning
minor = backward compatible
major = potentially breaking

Validation¶

XSD for structure and primitive constraints
semantic validator for: - unresolved references - dimension mismatch - enum/code mismatch - active override priority conflicts

8. Minimum Compliance Profile (v0.1)¶

An implementation is SPDM v0.1 compliant if it can:

parse all core value forms (scalar/enum/array/curve/map/struct)
resolve defaults and set values deterministically
evaluate variant overrides with deterministic conflict handling
preserve origin metadata needed for round-trip conversion
reject structurally invalid XML and semantically invalid references

SPDM v0.1 (Synarius Parameter Data Model)¶

Scope¶

1. Conceptual Model¶

Parameter¶

ParameterSet¶

ParameterValue¶

Type system¶

Units and quantities¶

Constraints¶

Variants¶

Defaults vs actual values¶

Metadata¶

2. Design Principles¶

3. XML Representation¶

Root¶

Normative top-level order¶

ParameterDefinition shape¶

Value encoding¶

Variant handling¶

4. XSD (reference)¶

5. Example SPDM file¶

6. Mapping Considerations¶

DCM2 -> SPDM¶

CDFX -> SPDM¶

PAR -> SPDM¶

7. Implementation Notes¶

Parsing strategy¶

Suggested internal structures¶

Versioning¶

Validation¶

8. Minimum Compliance Profile (v0.1)¶

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