IEC 60870-5-104 (client)

Every incoming information object is joined to a configured measurement by {common_address}:{type_id}:{ioa} — an ASDU with common address 100 and a double-point object at IOA 2001 becomes 100:DP:2001. A point that isn't configured is dropped.

• SP single point, DP double point, ST step position, BO bitstring, MEn normalized value, MEs scaled value, IT integrated totals — all discrete.
• MEf short floating point — the only type_id that produces an analogical measurement. Rescale a discrete one with a conversion (see Agent configuration) if MEn/MEs needs engineering units.

{
  "name": "pos",
  "equipment": "bay1.brk52",
  "type": "discrete",
  "store": true,
  "driver": {
    "type": "discrete",
    "common_address": 100,
    "type_id": "DP",
    "ioa": 2001
  }
}

Same common_address/ioa, with a numeric ASDU type_id instead of the string codes above. select_common_address, select_type_id, select_ioa, and select_value are optional and add select-before-operate — omit them to operate directly. A fixed-value discrete command (45 for C_SC_NA_1, for example):

{
  "name": "pos.open",
  "equipment": "bay1.brk52",
  "driver": {
    "type": "discrete",
    "value": 1,
    "common_address": 100,
    "type_id": 45,
    "ioa": 2001,
    "select_common_address": 100,
    "select_type_id": 45,
    "select_ioa": 2001,
    "select_value": 0
  }
}

An analogical command carries no fixed value in the config — the setpoint comes from the command request at runtime instead (50 for C_SE_NC_1, a short floating point setpoint, for example). The same select-before-operate fields apply here too:

{
  "name": "setpoint",
  "equipment": "bay1.brk52",
  "driver": {
    "type": "analogical",
    "common_address": 100,
    "type_id": 50,
    "ioa": 3001
  }
}