API & SYSTEM INTEGRATION ｜ API & System Integration

Through clear interface boundaries,
connect devices, sites, and business systems

Build system-integration capability contract-first: define northbound and southbound boundaries, unify telemetry, event, command, and acknowledgement semantics, so every system interaction is identifiable, verifiable, auditable, and evolvable.

The goal of integration is not that the interface can be called, but that data, commands, responsibilities and failures are clearly bound.

Total interfaces 156

Mapped fields 1,248

Command channels 36

Integration objects 28

Critical interface status 100%

Northbound applications and business systems

GRID Grid / dispatch Utility / Grid

EMS Client EMS Customer EMS

CMMS Equipment management CMMS

ERP Enterprise resource plan ERP

DATA Data Lake / Cloud Platform Data Lake / Cloud

SVC Service platform Service Platform

Southbound devices and site systems

BMS BMS Battery management system

PCS PCS Power Conversion System

MTR Measurements Meters

WX Weather stations Weather Station

SCADA Site SCADA Site SCADA

IO Support equipment Auxiliary / IO

01 Integration landscape and accountability boundaries System of record and ownership

BMS

PCS

Meters

Weather

Site SCADA

TIANCHU BESS
Integrating Border

Utility / Grid

Customer EMS

CMMS

ERP

Data Lake

Service Platform

Telemetry/ Status Events / File Commands Confirm / Results

02 Protocol and interface layer Supported integration mode

Southbound protocol stack Southbound

Modbus TCP / RTU Field equipment acquisition and control

IEC 61850 MMS / Electricity automation

IEC 60870-5-104 Remote / Schedule

CAN / RS485 Device Internal / Secondary bus

SNTP / NTP Time Sync

Northbound interface patterns Northbound

REST API Query / Control / Configuration

Real-time streaming MQTT / Kafka

Message queue AMQP / Kafka

File exchange SFTP / HTTPS

Modbus TCP / RTU: For industrial on-site objects such as PCS, metering and assistive equipment, support is provided for controlled rotation and memory mapping.

03 Interface compacts Interface Contact

Category	Interface Item	Object	Field / Schema	Units	Time	Quality	Orientation	Refresh / Trigger	Owner	Authority
Telemetry/ Status	EMS.DC.Volt	BESS-01 / Rack-12	dc_voltage	V	ISO8601 / UTC	GOOD	North	real time 1s	TIANCHU	—
	PCS.AC.Power	BESS-01 / PCS-01	ac_active_power	kW	ISO8601 / UTC	GOOD	North	real time 1s	TIANCHU	—
	Meter.Import.Energy	BESS-01 / Meter-01	import_energy	kWh	ISO8601 / UTC	GOOD	North	15 min	TIANCHU	—
Event / File / Master Data	Alarm.Event	BESS-01	event_alarm	—	ISO8601 / UTC	—	North	Event Trigger	TIANCHU	—
Event / File / Master Data	Device.Master	BESS-01	device_master	—	ISO8601 / UTC	—	Double	Batch	Customer	Customer System
Command	PCS.ActivePower.Set	BESS-01 / PCS-01	set_active_power	kW	ISO8601 / UTC	—	North-South	Command Trigger	Customer	Customer EMS
Command	BMS.ChargeLimit.Set	BESS-01 / Rack-04	charge_limit	%	ISO8601 / UTC	—	North-South	Command Trigger	Customer	Customer EMS
Confirmation / Results	Cmd.Ack	BESS-01	cmd_ack	—	ISO8601 / UTC	GOOD	North	Operation Trigger	TIANCHU	—
Confirmation / Results	Cmd.Result	BESS-01	cmd_result	—	ISO8601 / UTC	GOOD	North	Operation completed	TIANCHU	—

DC Voltage Telemetry: Direct-flow bus voltage is real-time telemetry, with a single time stamp and Quality, not allowed to be written directly to consumers north.

04 Exchange modes Choose by business semantics—not every datum uses the same transport

POLL Polled read 1s-60s cycle collects, suitable for continuous Telemetry.

EVT Status / event notification Change drivers, for alarms and events.

MSG Message-based commands Step forward, must take AK.

FILE Batch / historical files SFTP / HTTPS, with version and verification.

MASTER Master data / configuration Low frequency changes require approval and version.

05 Mapping and transformation workbench Traceable links from source to target

Source tag Source Tag

PCS.AC.Power
unit: kW
Local TZ

Canonical object model Canonical Model

asset: PCS-01
metric: active_power
category: power

Standardization Normalization

unit: kW
TZ: UTC
scale: 1

Validation rules Validation

required
range check
timestamp check

Target schema Target Schema

EMS.PowerPoint
ISO8601
quality=GOOD

06 Version and compatibility management Evolvable · traceable

Interface/ Protocol	Current Version	Backward compatibility	Abandoned plan	Impact on consumers	Migration Window	Status
Telemetry API(REST)	v2.3.1	Compatible v2.0+	Old v1 is disabled at 2024-12-31	Customer EMS	2024-06 → 2024-11	Running
Event Streaming(Kafka)	v1.5.0	Compatible v1.3+	—	Alert / Data Platform	—	Running
Command API(REST)	v2.1.0	Compatible v1.9+	2025-03-31	Part old client	2024-10 → 2025-02	Planning
File Interface(SFTP)	v1.2.0	Compatible v1.1+	—	Internal services	Ongoing	Running
IEC 104 Profile	v1.0.2	Compatible v1.0+	—	SCADA System	—	Running

Principle of compatibility: Breaking Change must upgrade Major Version, preserve the migration period, impact assessment, consumer lists and roll-back programmes;

07 Secure command handshake Safety first · controlled failure

1 Request Command Request

2 Authentication Auth Reference

3 Target / scope validation Target Validation

4 Equipment readiness check Ready Check

5 Execute Release Execute

6 Acknowledgement Acknowledgement

7 Measured outcome Measured Outcome

Timeout: 30 s

Replay: Ban

♪ And so on ♪ Command ID

Failed: Hold safe state

08 Sandbox and test assurance

CONF Conformance testing Schema / Contractor Consistency

CON Contract testing Producer / Consumer Certification

NEG Negative testing Invalid / Overstepped / Missing Fields

LOAD Performance and Pressure Conjunctive / Peak Swallow

CLK Time and Order Clock deviation / sequence verification

SITE Site interconnect verification E2E Site Test

09 Integration issue closed-loop case Unit/ Time Zone Inconsistencies

• Discovery of problems EMS needs PCS power.

Request

Data source confirmation Southbound label confirmed.

PCS.AC.Power

3 Reason analysis Source is W, local time.

W / Local TZ

Map correction Unit and time harmonization.

kW / UTC

5. Return verification Reimplement Contractor Test.

100% PASS

• Software release Releases a new map version.

Mapping v2.2.1

10 Documentation and deliverables Auditable. Reusable.

ICD Interface specification Interface Spec

DICT Data Dictionary Data Dictionary

CMD Command Matrix Command Matrix

MAP Map File Mapping File

TEST Test report Test Report

COMP Compatible Matrix Compatibility

REL Issuance of notes Release Notes

CASE Support cases Support Case

11 Liability boundary Who's responsible for what?

TECH Interface technical boundary Protocol, Schema, Mapping

OWN Data ownership Course of Truth

SEC Security and authority IAM, Roles and Certificates

RUN Operational responsibilities Who can give a control order?

CHG Change ownership Version, migration, rollback

AUD Evidence and audit Logs, tests and deliverables

Core principles: One system connection must be clear at the same time. Technical boundary, data responsibility, command authority, security control, failure, version strategy and acceptance evidence(b) “Network has been reached” does not in itself mean that the System Information has been completed.