01
Field devices
PLCs, sensors, meters, or cameras emit signals through interfaces that fit the network already on site.
RS485 · MODBUS RTU · MQTT
Back to the iNut Edge architecture
M4 / INTEGRATION GUIDE
Bring field data into your system through a clear contract.
This guide shows how an integration team can move from field signals to a Local API, REST/JSON, or MQTT path. It is a reference contract for the first conversation; the endpoint, authentication, mapping, and handover scope are agreed after the site survey.
CONTRACT V1.0REVIEWED 06 AUG 2026REFERENCE BUILD · SURVEY-BOUND
01 / DATA PATH
Four touchpoints, one traceable path
Start with the current-state diagram: which devices emit data, which layer must keep it on site, and which system will consume the contract. Test each step independently before joining the full path.
02
iNut Edge
Read, normalize, buffer, and run the logic needed where the operation actually runs.
DATALOGGER · INUT PC · RUNTIME
03
Local API
Expose structured data for software to read, reconcile, or call back according to the agreed workflow.
REST/JSON · MQTT · API
04
Your system
An app, SCADA, CRM, or ERP consumes the contract and decides presentation, permissions, and retention.
SCADA · APP · CRM · ERP
02 / OWNERSHIP
Make every boundary someone can own
Clear boundaries stop a network issue from being mistaken for a UI issue, or an undecided mapping from becoming a device defect. Use this table to start the survey conversation.
| Boundary | Reference principle |
|---|---|
| Ingress | RS485 / Modbus RTU, MQTT, or a protocol agreed during the survey; include point list, units, and scaling rules. |
| Edge layer | Read devices, transform, buffer when the outside path is unreliable, and log enough context to trace one message. |
| Egress | REST/JSON, MQTT, or Local API within scope; schema, cadence, and error behavior are agreed before acceptance. |
| Application | User authentication, business permissions, screens, alerts, and retention belong to the integrated system. |
03 / REFERENCE CONTRACT
One payload that both teams can test
The example uses illustrative data. Replace point names, timestamps, units, authentication, and endpoint details with the mapping in the handover record.
SAMPLE REQUESTPOST /api/v1/telemetry
{
"source": "gateway-rs485-01",
"captured_at": "2026-08-06T09:30:00+07:00",
"points": [
{
"key": "line_01.temperature",
"value": 28.4,
"unit": "degC",
"quality": "good"
}
]
}SAMPLE RESPONSE202 ACCEPTED
{
"status": "accepted",
"accepted": 1,
"received_at": "2026-08-06T09:30:00+07:00",
"trace_id": "edge-demo-001"
}| Code | Reference meaning | Next action |
|---|---|---|
| 202 | The payload is valid and the receiving layer acknowledged it. | Keep trace_id for matching edge and application logs. |
| 400 | A required field is missing or has the wrong type. | Compare the payload with the agreed schema; do not guess the unit. |
| 401/403 | Credentials or calling permissions do not match. | Check the handover credential and the integration client's scope. |
| 409/422 | The message is duplicated or fails a mapping rule. | Compare request id, timestamp, point key, and schema version. |
| 5xx | The receiving layer cannot process the message temporarily. | Keep the message in the edge buffer under the agreed policy, then retry with control. |
This is a reference code table for the integration conversation, not a promise of a public endpoint. The actual codes and retry strategy belong in the acceptance record.
04 / TROUBLESHOOTING
Trace the first data point
When something fails, work upward: source and protocol, edge buffer, contract, then the application screen. This keeps evidence and logs at the right layer.
No payload
The device is not emitting data or edge cannot read the point.
Check: power, A/B wiring, slave ID, baud rate, parity, and read timing in the edge log.
Payload rejected
The receiving layer has data but the schema does not match the reference contract.
Check: point key, value type, unit, quality, and timestamp; keep trace_id when resending.
Data arrives late
The outside network is unreliable or edge is holding the message in its buffer.
Check: network state, capture time, send time, and the handed-over retry policy.
The app shows the wrong value
The message reached the system but business mapping is not correct.
Check: scale, unit, timezone, point name, and schema version at the consumer.
HANDOVER START
A diagram and point list are enough to begin
Share device models, protocols, point count, network constraints, and the system that should consume the data. iNut will help shape the edge layer, contract, and acceptance scope.