Why Build Your Own Equipment Monitoring?
Many factory managers realize their existing equipment either has no monitoring or only local indicator lights and simple threshold alarms. When equipment breaks down, a single shutdown can cost thousands to tens of thousands.
But buying a turnkey solution from major brands often costs hundreds of thousands — unaffordable for SMEs.
Actually, building a basic equipment monitoring system yourself isn't hard. This article covers the entire "sensor → data acquisition → transmission → platform visualization" workflow.
Step 1: Define Monitoring Objectives
Start with three questions:
**What parameters to monitor?** Temperature, vibration, current, RPM, pressure, or humidity?**How many devices?** 3 or 30? Scale directly impacts solution choices.**Do devices have existing signal interfaces?** PLC with Modbus? 4–20mA analog sensors or digital?Common equipment-to-parameter mapping:
Air compressor → discharge temperature, motor current, vibration, runtimeWater pump → bearing temperature, vibration, flow rate, currentCold storage → multi-point temperature, humidity, chiller unit statusElevator → door status, operation count, fault codes, leveling signalStep 2: Sensor Selection
**Temperature**: For industrial use, PT100 RTD or K-type thermocouples are recommended. Ambient (-40~120°C) use PT100 for stability; high temperature (>300°C) use K-type.
**Vibration**: For critical rotating equipment (compressors, pumps, fans), use IEPE accelerometers, ±50g range, 0.5–10kHz frequency response. Standard motors can use economy models.
**Current**: Split-core CTs — no-power-off installation. Select range based on rated current with 50% margin.
**Key Pitfalls to Avoid**:
Match sensor IP rating to the environment. Dusty workshops need IP65+; outdoor needs IP67.Keep signal cables away from VFDs and power cables — electromagnetic interference is the root cause of many false alarms.Mount sensors at points that reflect true equipment state, not arbitrary locations.Step 3: Data Acquisition & Transmission
This is the most critical part. The core device is the **DTU (Data Transfer Unit)**.
Which Protocol?
**Modbus-RTU**: The most universal industrial fieldbus. PLCs, VFDs, meters all support it. Best for wired collection within the same workshop.**MQTT**: Purpose-built for IoT, ideal for cross-network transmission. DTU connects via 4G/Ethernet to the cloud platform.**4–20mA**: Traditional analog, still widely used. Needs DTU analog input channels for conversion.Recommended Architecture
```text
Sensor/PLC → RS-485 (Modbus-RTU) → DTU → 4G/Ethernet (MQTT) → Cloud Platform → Dashboard/Alerts
```
**Key Selection Tips**:
Reporting frequency: 30s–2min is enough for temperature; vibration may need per-second (budget dependent).Local caching: DTU must support offline caching — unstable 4G signal is common in industrial sites.Power: Use 12V/24V DC where available; battery + solar for remote sites without mains power.Step 4: Cloud Platform Selection
Core capabilities required:
Device management & configuration: remote adjustment of collection frequency, alert thresholdsReal-time dashboard: temperature/vibration curves, device online statusAlert rule engine: threshold alerts, rate-of-change alerts, AI trend deviation alertsNotification distribution: WeChat, SMS, phone call graded pushWork order management: alert → dispatch → sign-in → repair record closed loop**DIY vs. Mature Platform?**
Unless you have a 5+ person dev team and aren't in a hurry to go live, strongly recommend using a mature platform. Building your own means spending months on device protocol adaptation alone.
Step 5: Alert & Work Order Closed-Loop
Data collection is only step one. Real value comes from:
When equipment is abnormal, the **right person** receives the **right alert** at the **right time**.Alerts must form a closed loop — from discovery to repair to confirmed recovery, fully traceable.A good alert system needs:
Graded strategy: Level 1 (shutdown risk) → immediate phone + WeChat; Level 2 (trend degradation) → WeChat alert; Level 3 (routine notice) → daily digest.Shift-based routing: Different teams for day/night shifts; alerts only go to on-duty personnel.Convergence: Same device + same alert type merged within time window to avoid spam.Summary: Startup Checklist
| Step | Time | Key Output |
|---|
| Requirements confirmed | 1 day | Monitoring parameter list, equipment ledger |
| Sensor procurement | 3-5 days | Sensors delivered and verified |
| DTU setup & online | 0.5 day/unit | Device data starts reporting |
| Platform configuration | 1 day | Dashboards and alert rules ready |
| Trial run verification | 3-7 days | No false/missed alerts confirmed |
From zero to full go-live, the entire pipeline can be operational in as fast as **one week**.
