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public:emscope:websocket_api

EMSCOPE WEBSOCKET PROTOCOL DOCUMENTATION

The Emscope software consists in a WebSocket server listening on port 8010 of the machine and a Web Server listening on the standard HTTP port 80 that serves the front end html and related files.

To configure, parametrize the measurements and manage the standards, a JSON style command set is used through a WebSocket connection.

1. First connection

Once the connection is stablished, the server will return the device’s serial number, measurement uncertainty and number of points, i.e:

{
  “SN”: “123456789”,
  “measurement_uncertainty”: "0.5 dB",
  “num_points”: 8192
}

2. Default values

The default values for measurements are:

  • Channel: LG
  • Detector: PK
  • Tracer: Clear/write
  • Units: dbuv
  • RWB: 9
  • Subranges: 10
  • Margin: 10
  • Active: true
  • Mode: circuit
  • input_attenuator: auto
  • reference_level: 100 (dbuV)

3. Commands and responses

The following parameters can be sent to configure the device:

Name Parameter Type Default
Channel measure_channel “lg”, “ng”, “cm”, “dm” “lg”
Detector type detector_type “pk”, “qp”, “av” “pk”
Tracer trace_type “clearwrite”, “maxhold”, “minhold”, “freeze” “clearwrite”
RBW rbw “9”, “200”, “120”, “1”, “10”, “200_9”, “1_10” “9”
Mode mode “circuit”, “modal” “circuit”
Reference level reference_level integer 100
Input attenuator input_attenuator {0..78} (integer), “auto” “auto”
Amplitude units amp_units “dbm”, “dbmv”, “dbuv”, “watts”, “volts” “dbuv”
Serial number SN string
Sweep time sweep_time {1..15} (float) 1
External loss attenuator external_loss External loss name (string) none

4. Changing RBW

After setting the RBW we shouldn't send any commands until the device it sends back the RBW value. This is so because a hot-change of firmware, that typically takes around 3.5 seconds, is required. To set a new RBW, send a rbw field with the string corresponding to the RBW:

{
  "rbw": "9"
}

RBW table:

Value RBW Frequency Standard
200 200 Hz 9 kHz - 150 kHz CISPR 16-1-1
9 9 kHz 150 kHz - 30 MHz CISPR 16-1-1
120 120 kHz 30 MHz - 110 MHz CISPR 16-1-1
1 1 kHz 10 kHz - 150 kHz MIL-STD-461
10 10 kHz 150 kHz - 30 MHz MIL-STD-461
200_9 200 Hz / 9 kHz 9 kHz - 30 MHz Dual-band
1_10 1 kHz / 10 kHz 10 kHz - 30 MHz Dual-band

5. Initial configuration

A typical initial configuration parameters example would be:

{
  "detector_type": "pk",
  "measure_channel": "lg",
  "trace_type": "clearwrite",
  "amp_units": "dbmv",
  "rbw": "9",
  "reference_level": 70,
  "input_attenuator": "auto",
  "sweep_time": "1"
}

6. Receiving the measurements

To start receiving measurements, we should at least send the trace_type. The measurements are sent in a values object immediately after the measure is done. The result contains an array of arrays recodesenting the frequency and the read value ( [frequency, value] ) Another key, named overload, will be set to true if an overload situation is detected. Example:

{
  "values": [
    [ 0, 0.024687 ],
    [ 7326, 0.014846 ],
    [ 10000, 0.00344 ],
    ...
  ],
  "overload": false
}

7. Locking the device to the current session

To ensure that the device is only being configured from one source, you ought to set a session_UUID variable to a random value. Use the same value for subsequent connections. I.e:

{
  "session_UUID": "12345qwerty"
}

This session UUID must be sent with every WebSocket connection. If the device is currently locked with another session UUID, the device will disconnect us with WebSocket close reason code 4003.

8. Standards (or Limits)

8.1 Getting the standards list

Send the field get_standards with a value of “true”:

{
  "get_standards": true
}

It will return a standards object with an array of standards with the following format:

"Standard name": [ { "rbw": value, "data":
  [ From frequency (Mhz), To frequency (Mhz), From Quasi-peak (dBuV), To Quasi-peak (dBuV), Average from Quasi-peak (dBuV), Average to Quasi-peak (dBuV) ],
  ...
  }
]

For example:

{
  "standards": [
    {
      "Standard One": { "rbw": "9", "data": [ 
        [1, 2, 3, 4, 5, 6],
        [7, 8, 9, 10, 11, 12],
        ...
      ]
      }
    },
    {
      "Standard Two": { "rbw": "200", "data": [ 
        [21, 22, 23, 24, 25, 26],
        [27, 28, 29, 210, 211, 212],
        ...
      ]
      }
    },
    ...
  ]
}

8.2 Creating a standard

To create a standard, send a name field with the name of the new standard, a modify field set to “false” and a values array in the same format we described before when receiving the standards list.

{
  "name":"New standard",
  "modify":false,
  "standard_rbw": "10",
  "values":[
    ["1","2","3","4","5","6"],
    ["11","12","13","14","15","16"],
    ...
  ]
}

8.3 Editing a standard

Send the same values as creating it, but with the field modify set to true and an additional field, original_name, just in case we wanted to rename the original name, i.e:

{
  "original_name": "New standard",
  "name":"Modified standard",
  "modify":true,
  "standard_rbw": "1",
  "values":[
    ["21","22","23","24","25","26"],
    ["11","12","13","14","15","16"],
    ...
  ]
}

8.4 Deleting a standard

Simply send a delete_standard with the name of the standard, i.e:

{
  "delete_standard": "Standard One"
}

9. Sessions (or Presets)

9.1 Getting the sessions list

Send the field get_sessions with a value of “true”:

{
  "get_sessions": true
}

It will return a sessions object with an array of sessions with the following format:

"Session name": [BLOB DATA],
  ...
]

For example:

{
  "sessions": [
    {
      "Session One": "{\"PROGRAM_VERSION\":1.25,\"id_counter\":2,\"current_center_freq_units\":\"mhz\",\"current_start_freq_units\":\"mhz\",\"current_stop_freq_units\":\"mhz\",\"current_span_units\":\"mhz\",\"current_center_frequency\":15000000,\"current_start_frequency\":0,\"current_stop_frequency\":30000000,\"current_span\":30000000,\"measure_mode\":\"circuit\",\"current_display_scale\":0,\"aDetectors\":[{\"type\":\"normal\",\"measure_channel\":\"lg\",\"trace_type\":\"clearwrite\",\"detector_type\":\"pk\",\"amp_units\":\"dbuv\",\"color\":\"red\",\"hidden\":false,\"standard\":null,\"id\":0,\"sweep_time\":1},{\"type\":\"normal\",\"measure_channel\":\"lg\",\"trace_type\":\"clearwrite\",\"detector_type\":\"pk\",\"amp_units\":\"dbuv\",\"color\":\"red\",\"hidden\":false,\"standard\":null,\"id\":1}],\"reference_level\":100,\"reference_level_volts\":0.1,\"amplitude_step\":10,\"aCurrentFreq\":[150000,30000000],\"aCurrentSpan\":[0,100],\"aMarkers\":[[],[]],\"aMMarkers\":[],\"aStandards\":{\"CISPR 22 CLASS A\":[[\"0.15\",\"0.5\",\"79\",\"79\",\"66\",\"66\"],[\"0.5\",\"30\",\"73\",\"73\",\"60\",\"60\"]],\"CISPR 22 CLASS B\":[[\"0.15\",\"0.5\",\"66\",\"56\",\"56\",\"46\"],[\"0.5\",\"5\",\"56\",\"56\",\"46\",\"46\"],[\"5\",\"30\",\"60\",\"60\",\"50\",\"50\"]]},\"aStandardsQuasiPeak\":{},\"aStandardsAverage\":{},\"active_tab\":1,\"ZERO_SPAN_MODE\":false,\"amp_units\":\"dbuv\",\"rbw\":\"9\",\"input_attenuator\":\"auto\",\"sweep_time\":1,\"current_color_theme\":\"dark\"}",
        ...
      ]
    },
    {
      "Session Two": "......",
        ...
      ]
    },
    ...
  ]
}

9.2 Creating a session

To create a session, send a session_name field with the name of the new session, a modify field set to “false” and a session_values array in the same format we described before when receiving the sessions list.

{
  "session_name":"New session",
  "modify":false,
  "session_values": ".....",
    ...
  ]
}

9.3 Editing a session

Send the same values as creating it, but with the field modify set to true and an additional field, original_session, just in case we wanted to rename the original name, i.e:

{
  "original_session": "New session",
  "session_name":"Modified session",
  "modify":true,
  "values": "......",
    ...
  ]
}

9.4 Deleting a session

Simply send a delete_session with the name of the session, i.e:

{
  "delete_session":"Session One"
}

10. External loss attenuators

10.1 Getting the external loss attenuators list

Send the field get_external_losses with a value of “true”:

{
  "get_external_losses": true
}

It will return a external_losses object with an array of external loss attenuators with the following format:

"External loss attenuator name": [ [ Frequency (Mhz), Line (dB), Neutral (dB) ], [ Frequency (Mhz), Line (dB), Neutral (dB) ], ... ]

For example:

{
  "external_losses": [
    {
        "External loss attenuator 1": [ [ 1, 2, 3 ], [ 2, 3, 4 ], ... ]
    },
    {
        "External loss attenuator 2": [ [ 10, 20, 30 ], [ 20, 30, 40 ], ... ]
    },
    ...
  ]
}

10.2 Creating an external loss attenuator

To create an external loss attenuator, send an external_loss_name field with the name of the new external loss attenuator, a modify field set to “false” and a values array in the same format we described before when receiving the external loss attenuators list.

{
  "external_loss_name":"New External loss attenuator",
  "modify":false,
  "values":[
    ["1","2","3"],
    ["10","20","30"],
    ...
  ]
}

10.3 Editing an external loss attenuator

Send the same values as creating it, but with the field modify set to true and an additional field, original_external_loss_name, just in case we wanted to rename the original external_loss_name, i.e:

{
  "original_external_loss_name": "New External loss attenuator",
  "external_loss_name":"Modified External loss attenuator",
  "modify":true,
  "values":[
    ["11","22","33"],
    ["21","22","23"],
    ...
  ]
}

10.4 Deleting an external loss attenuator

Simply send a delete_external_loss with the name of the external loss attenuator, i.e:

{
  "delete_external_loss": "External loss attenuator 1"
}

11. Report lists

To generate a report list, we must send 3 values: standard (the standard name string), subranges (number of subranges, an integer) and margin (the margin, an integer), i.e:

{
  "standard": "One standard",
  "subranges": 10,
  "margin": 10
}

The answer to the request will be a boolean frase and a report object with an array of arrays in the following order:

[
 Marker (integer),
 Frequency in Mhz (float),
 Peak level in dBuV (float),
 Quasi-Peak level in dBuV (float),
 Quasi-Peak limit in dBuV (float),
 Distance to Quasi-Peak limit [dB] (float),
 Average level in dBuv (float),
 Average limit in dBuV (float),
 Distance to Average limit [dB] (float),
 Channel (string),
 Compliance (PASS/FAIL)
]

The frase will be true if fewer than 6 emissions are within 10dB of the observed limit, and false otherwise.

For example:

{
  "report": [
    [ 1, 5, 116.964216, 116.418941, 119.000000, 10.000000, 116.480995, 109.000000, 10.000000, "L", "PASS" ],
    [ 2, 6, 313.963336, 133.418211, 1123440000, 111220000, 334.440995, 239.020000, 30.000000, "N", "FAIL" ],
    ...
  ],
  "frase": true
}

12. Miscellaneous

12.1 Getting the activated licenses

Send the field get_licenses with a value of “true”:

{
  "get_licenses": true
}

As a response you will get a licenses object with an array with the name of each activated licenses:

{"licenses": [ "emi", "osc" ]}

12.2 Getting the current PCB and FPGA temperature

Send the field get_temps with a value of “true”:

{
  "get_temps": true
}

As a response you will get a temperatures object with an array with the celsius degrees. The first value is for the PCB, the second one for the FPGA:

{"temperatures": [ 45.12345, 50.12345 ]}
public/emscope/websocket_api.txt · Last modified: 2020/06/25 10:32 by admin