Mitsubishi Electric’s M-Net Adaptors

Mitsubishi Electric’s M-Net Adaptors

M-NET Adaptors installed in M series indoor units and P series outdoor units allow for M-NET control of heat pump and air conditioning systems.  The choice of gateway adapters such as LMAP04 for LONWORKS or BAC-HD150 for BACnet allows M-NET network to connect with building management systems (BMS allowing control of units via Central Controller or ME controllers via M-NET and locally with MA controller or infrared wireless remote controller.

M-NET is a Mitsubishi Electric proprietary control protocol used for communication between Mitsubishi Electric devices. The line between connected devices consists of a single, flexible and shielded 2-wire bus cable. M-Net may be interfaced with all open building management protocols (KNX, Modbus, LON, BACnet).

 Interface adapters like MAC-334IF-E  are compatible with M and S Series, PAC-IF01MNT-E for MXZ models, and PACSJ95MA-E / PAC-SJ96MA-E for P-Series, enabling M-NET connections to the respective units. M-Net Interfaces are connected via the CN105 port ( 5-pin connector) on the indoor unit control board whereas the outdoor unit adaptors are powered by outdoor control board CNMNT and CNVMNT connectors.

 Transmission Line Diagram


All adapters have terminals A and B for connection to 2 wire M-Net network and shield connected to S ground terminal. Unit supplying M-Net 30VDC power is the only one that the S-terminal is grounded with ground accessory wire. The polarity of the A and B terminals does not matter. To avoid any noise interference from ground loops, a 16AWG 2-wire shielded cable must be used for installation. Each unit on the M-Net bus has a distinctive address. Rotary switches are provided on all adapters to set these addresses.

 

Before installation, it is important to verify the compatibility of the adapter with both indoor and outdoor units, as certain combinations may not be suitable.

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