JSON API

The backend server communicates using stringified json. The general format for requests is as follows.

{
  "cmd": <command>,
  "args": {
    ...
  }
}

Requests#

Below is a list of the valid requests.

Start#

To start a log, use to following json.

{
  "cmd": "start",
  "args": {
    "plc": <plc address>,
    "tag": <tag name>,
    "readinterval": <read interval>,
    "writeinterval": <write interval>
  }
}

Stop#

To stop a log, use the following.

{
  "cmd": "stop",
  "args": {
    "plc": <plc address>,
    "tag": <tag name>
  }
}

Status#

To get the plcs that the server is connected to and the tags it is logging, send this request.

{
  "cmd": "status"
}

If the request is completed successfully, the response will be formated as follows.

{
  "status": 200,
  "plcs": {
    "172.16.13.200": "172.16.13.200/0", // Represents a pyconpro.PLC instance
    ...
  },
  "logs": {
    "172.16.13.200": {
      "test": { // Represents an imslogger.Logger instance
        "plc": "172.16.13.200/0",
        "tag": "test",
        "read": <read interval>,
        "write": <write interval>
      },
      ...
    },
    ...
  }
}

Responses#

OK#

If the server successfully starts or stops a logger, you will recieve this.

{
  "status": 200
}

Error#

If any error for any request is encountered, the server will send the following.

{
  "status": 500,
  "err": <error message>,
  "traceback": <traceback>
}