JSON Format for Data Items

A JSON object describing a data item has the following syntax:

{
  "@Skill.S7.Item": {
    "name": "Charge Name",
    "UUID": "be4ccfb9-eff1-4563-b23a-0e22a770bd14",
    "ACL": { ... },
    "dataType": "String",
    "bufferLength": 32,
    "address": "MW14",
    "writable": true,
    "command": "PLC 1.Command"
  }
}

Object Members

name	A string value containing the name of the data item. The name is used to construct the data item’s primary key.
UUID	A string value containing the unique UUID of the data item.
ACL	An optional JSON object containing the element ACL of the data item. The format of the object is described under JSON Format for ACLs in the Xentara user manual.
dataType	The data type of the variable the data item refers to, in the target S7 PLC.
address	The address of the variable the data item refers to, in the target S7 PLC.
bufferLength	The buffer length of the string variable the data item refers to, including the two length bytes used by the S7 “String” data type. The value of this parameter must be at least 3: two bytes for the buffer size and string length, and at least one actual data byte. This parameter is required for data items with the data type of "String", and must not be added for other data types. Attention The value of this parameter is the length of the string variable’s buffer in the target PLC’s memory, and not the length of the string itself. An S7 string buffer has 2 length bytes before the actual string data, so the buffer size must be 2 + the maximum length of the string.
writable	An optional Boolean value to enable or disable write operation for the data item. Setting the value to false, makes the data item read only. If you do not specify this parameter, then the data item will not be writable.
command	The Command that should be used to read and write the data item.