MQTT Data Protocol

The data protocol is based on ProtoBuf.

Value Type

enum ValueType
{
  Unknown = 0;
  Integer = 1;  
  Double = 2;   
  Boolean = 3;  
  String = 4;   
  Bytes = 5;    
}

Histroy Compression

message CompressSpec
{
  bool enable = 1;  // whether to enable compression, the default is false
  float value = 2;  // compression value
  int64 maxElapse = 3;  // maximum upload cycle (s)
}

Meta Tag

• Metatag

message MetaTag
{
  int32 version = 1;        // tag version, update when tag changes
  string name = 2;      // tag name (start with character and no illegal character)
  string showName = 3;      // tag display name (optional)
  string description = 4;   // tag description (optional)
  ValueType type = 5;       // tag value type
  string unit = 6;      // tag value unit
  string range = 7;     // tag value range (lower limit-upper limit), range is closed interval, eg.0-100 (optional)
  RtdValue defaultValue = 8;    // default tag value (optional)
  bool storage = 9;     // whether to synchronize value changes to supOS (optional)
  CompressSpec compress = 10;   // tag compression (optional)
}

• Metatag Sequence

message MetaTagSequence
{
  repeated MetaTag tags = 1;
}

Real-time Data

• Real-time Data

message RtdValue
{
  int64 timeStamp = 1;  // UTC timestamp
  int64 quality = 2;    // quality code, 0 means normal
  oneof value
  {
​    int64 intVal = 3;
​    double dblVal = 4;
​    bool boolVal = 5;
​    string strVal = 6;
​    bytes bytVal = 7;
  }
}

• Real-time Data Name

message NamedValue
{
  string name = 1;  // tag name
  RtdValue value = 2;   // tag real-time value
}

• Real-time Data Sequence

message ValueSequence
{
  repeated NamedValue values = 1;
}

• Automatic Network Replenishment Same as ValueSequence.

Event Data

message RtdEvent
{
  string topic = 1;
  bytes payload = 2;
}

Time Synchronization

message GatewayCoordinate
{
  int64 localTimeStamp =1;
}

message ServerCoordinate
{
  int64 localTimeStamp =1;
  int64 serverTimeStamp =2;
}