História stránky

TxtI, TxtO, Qi,
Ci, Co,
Ai, Ao,
Di, Do,
TiR, ToR

If Payload Type=JSON, the message is parsed as JSON data. The json_address value specifies the name of the JSON field whose value is to be assigned to the I/O tag. 
For JSON messages that can be structured, the syntax level1.level2.level3 ... is supported, e.g. rx.current, and if they contain fields (indexed from 1) also syntax level1[index1].level2[index2].level3 ... is possible, e.g. rx.gwrx[1].time.
Since the JSON message itself can be an array, the address can also start with an index, e.g. JA=[1].batt_cell_v_avg

For other examples, see the description of the LoRaWAN protocol's Envelope type I/O tags.

Note: If you need to read the entire array, it is possible to configure the Destination column of the structure and specify an address with index 0, e.g. JA=myarray[0] or JA=struct.myarray[0].itemA

Writing to an I/O tag with a JSON address is also supported, but it must not have indexes. Examples of correct addresses for writing:

• JA=myaddress
• JA=mystruct.mylevel.myitem

When writing, the generated JSON contains the value itself and optionally a timestamp, if the station protocol parameter Time Field Name or the line parameter Time Field Name is set.
Note: Before writing to an I/O tag with a JSON address, a topic must first be set (an I/O tag with the OUT_TOPIC address). If the I/O tag with the OUT_TOPIC address does not exist, the station address will be used directly as the Topic (if it is empty, the writing will not be performed).

TxtI, TxtO, Qi,
Ci, Co,
Ai, Ao,
Di, Do,
TiR, ToR, TiA, ToA

If Payload Type = Sparkplug Host/Edge Node, the message is parsed as Sparkplug data (a binary format built on Google Protocol Buffers). Sparkplug data contains metrics that have text identifiers (sparkplug_address) or possibly numeric aliases (alias).

Reading template items  is possible by specifying sparkplug_address in the format <TemplateName1><Separator><TemplateName2><Separator> ... <Separator><ItemName> where:

• <TemplateNameX> is the name of the template/sub-template
• <Separator> is the separator for individual levels (standard characters "->", which can be changed with the Item Separator parameter if this sequence occurs in template/item names)
• <ItemName> is the item name of the deepest nested template

Examples of template item addresses:
SA=Template1->SubTemplate2->Item
SA=secUDT->sec

Reading dataset items (equivalent to structured variables in D2000) is possible by specifying sparkplug_address in the format <DatasetName>[<Row>]^<ColumnName> where:

• <DatasetName> is the name of the dataset (it can also be part of a structure, e.g., Template1->SubTemplate2->Dataset3)
• <Row> is the column number (1..N) or the "*" character. In the latter case, it is possible to configure the Destination column to which all rows are written (values ​​from the first row of the corresponding column are written to the I/O tag)
• <ColumnName> is the name of the dataset column

Examples of dataset item addresses:
SA=Performance[3]^ActivePower
SA=Machine2->Parameters[1]^ActivePower
SA=DHS/Formation Data->Reservoir Parameter[*]^Gas density

For output I/O tags, the value type can be explicitly (ST=type). Simple types are supported (not template items/dataset items):

• Int8
• Int16
• Int32
• Int64
• UInt8
• UInt16
• UInt32
• UInt64
• Float
• Double
• Boolean
• String
• DateTime
• Text
• Unknown
  (undefined type)

If the value type is not specified, the default value depends on the type of I/O tag:

Note: There is no difference between the String and Text types.
Note: for Payload Type = Edge Node, the D2000 KOM process sends DBIRTH/NBIRTH messages that contain only I/O tags (both input and output ones) with a defined value type. If we want to hide some (input) I/O tags, we need to set ST=Unknown in the address.

For Payload Type = Edge Node, it is also possible to specify a numerical alias (SAL=alias) as a natural number (0, 1, 2, ...) for both input and output I/O tags. The alias of the I/O tag within the station must be unique. Aliasing allows you to reduce the size of the transmitted data: in the NBIRTH/DBIRTH message, both the text identifier (sparkplug_address) and the alias are specified for each I/O tag; in the NDATA/DDATA messages, only aliases that are shorter than the text addresses are sent. Alias ​​is only used if Sparkplug Alias Mode = "Default (SAL=alias)".
Note: If aliases are used in the I/O tag address in Payload Type = Sparkplug Host mode, they will be replaced by aliases from the NBIRTH/DBIRTH message. However, if for some reason the Edge Node does not send these messages (and sends NDATA/DDATA with aliases), aliases can be useful for matching a text name with an alias.

The PUBLISH message created during writing contains a Topic derived from the station address. The message type depends on the station address:

• for Payload Type = Sparkplug Host, depending on whether it is an Edge Node (NCMD) or Device/Sensor (DCMD)
• for Payload Type = Edge Node, depending on whether it is an Edge Node (NDATA) or Device/Sensor (DDATA)

The Payload of the message contains a timestamp, a value type (type), a written value (encoded according to the specified value type), and a metric name (sparkplug_address) or an alias.

TxtI

The I/O tag is used to convert the Sparkplug payload into a JSON representation, which can then be processed, e.g., in an ESL script. Depending on the Convert Datatype/Timestamp to Text parameter, a textual representation of the value type and timestamp is also added. 
An example of value:

{"metrics":[{"datatype":3,"int_value":7338992,"name":"Corrected Vol Acc Stn","timestamp":1729664005479}],"seq":32,"timestamp":1729664005479}

After formatting into a readable form:

{
    "metrics": [
        {
            "datatype": 3,
            "int_value": 7338992,
            "name": "Corrected Vol Acc Stn",
            "timestamp": 1729664005479
        }
    ],
    "seq": 32,
    "timestamp": 1729664005479
}

An example of a more complex value containing properties and a dataset, and also displaying a textual representation of the data type (datatype_txt) and timestamp (timestamp_txt) as a result of the set parameter Convert Datatype/Timestamp to Text:

{
    "metrics": [
        {
            "datatype": 12,
            "datatype_txt": "String",
            "name": "Node Properties/Configuration",
            "string_value": "{}",
            "timestamp": 1730305529539,
            "timestamp_txt": "30-10-2024 17:25:29.539"
        },
        {
            "alias": 30064771073,
            "datatype": 5,
            "datatype_txt": "Uint8",
            "int_value": 0,
            "name": "Node Properties/Missing Param",
            "properties": {
                "keys": [
                    "usage"
                ],
                "values": [
                    {
                        "string_value": "technical information",
                        "type": 12,
                        "type_txt": "String"
                    }
                ]
            },
            "timestamp": 1730305529537,
            "timestamp_txt": "30-10-2024 17:25:29.537"
        },
        {
            "alias": 0,
            "dataset_value": {
                "columns": [
                    "topic_name",
                    "offset",
                    "length",
                    "crc"
                ],
                "num_of_columns": 4,
                "rows": [
                    {
                        "row": [
                            "N/A",
                            0,
                            0,
                            0
                        ]
                    }
                ],
                "types": [
                    12,
                    7,
                    7,
                    7
                ],
                "types_txt": [
                    "String",
                    "UInt32",
                    "UInt32",
                    "UInt32"
                ]
            },
            "datatype": 16,
            "datatype_txt": "DataSet",
            "name": "Node Control/FW Update",
            "timestamp": 1730305529537,
            "timestamp_txt": "30-10-2024 17:25:29.537"
        }
    ],
    "seq": 0,
    "timestamp": 1730305529536,
    "timestamp_txt": "30-10-2024 17:25:29.536"
}