MAC36NL - iSMA Modbus Tunnel - The tunnel function is not properly executed

Issue

After configuring the iSMAModbusTunnel component to a proper TCP port and RS485 port (COM), it is not possible to connect with the FCU controllers from the FCU Updater.

Possible causes and solutions

• COM port busy with another driver

• Wrong project configuration in FCU Updater

• Unsupported Niagara version

COM port busy with another driver

FCU-family controllers are connected to the RS485 interface to monitor them with a ModbusAsyncNetwork or BACnetNetwork drivers with the MstpPort in the MAC36NL controller. Therefore, adding the iSMAModbusTunnel often creates a conflict as only one driver can occupy the same RS485 interface (COM port) at the same time.

Solution

The solutions is to remove the COM port from either ModbusAsyncNetwork → Serial Port Config (Port Name slot) or BacnetNetwork → Bacnet Comm → Network → MstpPort → Link (Port Name slot) and to switch off ModbusAsyncNetwork or MstpPort in the Enabled slot. Then, turn the iSMAModbusTunnel component off and on in the Enabled slot.

Wrong project configuration in FCU_Updater

By matter of routine, the user may open the most frequently used project in FCU Updater, which is configured to a serial connection with FCU controllers. In such a case, the iSMAModbusTunnel connection on the MAC36NL controller will not discover anything.

Solution

Add a new project in FCU Updater, which is configured to the Modbus TCP gateway and in the Gateway IP Address field, set the MAC36NL controller IP address.

Unsupported Niagara version

It is a known error of a faulty operation of iSMAModbusTunnel on the MAC36NL controller with Niagara 4.10.0.154 version. The bug is fixed for the 4.10.1.36 version.

Solution

Upgrade the Niagara version on the MAC36NL controller to 4.10.1.36 or higher, supported by MAC36NL controllers.