Integrating to a building management system

Modbus RTU over RS-485 for Nordicco HVLS fans

Based on “Advanced Operations – Integrating to a Building Management System”, vers. 1.7.Open the PDF

Your installation

The guide shows only the steps that apply to these answers.

Fans on the line

Parity (DIP switch 2, position 6)

Baud rate (position 7)

Address (position 8)

Inputs wired at the drive

Leave empty when only Modbus is wired.

Before you start

Warning: Get written approval before you open the drive

Safety-criticalManual p. 2

Connecting to the Modbus terminals requires accessing the NORDICCO® system drive, which voids the warranty unless prior written approval has been obtained from the manufacturer.

Contact Nordicco (+45 73 70 90 83, info@nordicco.eu) before you start.

Done

A couple of key things to consider before you start

Manual p. 3

Use only shielded Modbus (RS-485) cable, with a twisted pair for the data and a conductor for the common.
Maximum 60 m of cable between fans.
Maximum total network cable length of 500 m.
If you face a noise issue, you can add a 10K resistor from the digital ground (GND terminal) to the chassis. Generally, only one connection to the chassis throughout the network is required.
It is not recommended to use other equipment than NORDICCO® HVLS fans and NORDICCO® sensors in a daisy chain setup.

The drive speaks Modbus RTU on a two-wire RS-485 line

The fan is a Modbus slave; the BMS is the master and asks one fan at a time. How such a line is built – topology, cable, terminations, biasing, addresses, serial settings – is laid down in the MODBUS over Serial Line specification and implementation guide V1.02 (modbus.org). This guide refers to it by section, and says where the drive differs from it.

Your progress is saved on this device only.