The following schema describes the JSON data structure for a request for action by TSO:

{
  "TSO RESPONSE":{
    "description":"TSO action request from the client",
    "type":"object",
    "properties":{
      "VER":{
        "description":"TSO response JSON version identifier",
        "type":"string",
        "maxLength":4,
        "required":true
      },
      "ACTION":{
        "description":"action request text - ATTN=attention request",
        "type":"string",
        "enum":["ATTN"]
      }
    }
  }
}