Quick guide for installing, wiring, and using the Vaisala GMW87M CO2 and temperature wall‑mounted transmitter.
The GMW87M is a wall‑mounted CO₂ and temperature transmitter designed for harsh environments. It connects via an RS‑485 port using Modbus RTU and can be configured with DIP switches on the circuit board.
The guide covers product overview, safety, regulatory compliance, installation steps, wiring details, Modbus communication settings, troubleshooting, technical specifications, warranty, and support information. This manual is written in Chinese.
| CO₂ measurement range | 0 – 5000 ppm |
|---|---|
| Accuracy (20‑30 °C) | ±(30 ppm + 3 % of reading) |
| Power supply voltage | 18 – 35 VDC (or 24 VAC ±20 %) |
| Maximum current consumption (18 VDC) | 45 mA |
| IP protection rating | IP64 |
| Weight | 160 g |
Up to eight transmitters can share a single RS‑485 bus.
The address is set with DIP switches on the board; the address range is 1 to 247.
Check the screw terminal connections, power voltage, wiring polarity, RS‑485 grounding, and DIP switch settings; reseat the terminal block if needed.