Meltem M-WRG-S

Things to watch for

01

The gateway cannot communicate with the Meltem M-WRG-S. What should I check?

Verify that the RS485 wiring polarity (A and B) is correct and that both devices use identical serial settings: 9600 baud, same parity, and same stop bits. Also confirm that Modbus RTU is enabled on the ventilation unit.

02

Can I connect multiple Meltem units to one ModbusCloud gateway?

Yes. Use a daisy-chain RS485 bus topology and assign a unique Modbus slave address to each M-WRG-S unit. Add a separate template instance in ModbusCloud for each address.

03

Do I need a termination resistor on the RS485 bus?

For short cable runs with only one or two units, termination is often not required. For longer runs or buses with many devices, place a 120 ohm termination resistor at each end of the bus to reduce signal reflections.

04

Which firmware version is required on the Meltem M-WRG-S for Modbus support?

Refer to the Meltem product documentation for your specific hardware revision. Some older units may need a firmware update to enable the Modbus RTU interface over RS485.

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