BACnet User Manual

About the Manual	3
Introduction to BACnet communication2. Introduction to BACnet communication	3
BACnet: Installation and field wiring hardware	4
BACnet Module: Installation	4
BACnet Module, Field Wiring	5
Terminating Resistor	6
BACnet Module, programming	6
NPU tool	6
BACnet baud rate and address	7
Appendix & troubleshooting	10

1. About the manual

This manual describes the information needed to operate Infinitum Aircore EC+ motors using the BACnet protocol. This manual should be used in conjunction with the Aircore EC+ Installation Operation and Maintenance (IOM) Manual.

Abbreviations
BACnet Building Automation Control Network
BACnet MS/TP BACnet Master-Slave Token Passing

2. Introduction to BACnet Communication

BACnet is a common motor control protocol used in HVAC applications. This protocol is defined by ANSI/ASHRAE/ISO Standard 135-2004. The protocol is used for building automation and control describing the interaction between devices and systems. The protocol uses an object-oriented model for data and commands. BACnet has 6 types of communication networks to transmit messages with each defining the physical and data link communication layers. The six network types are:

BACnet ARCnet
BACnet Ethernet
BACnet Lontalk
BACnet MS/TP
BACnet Point-to-Point
BACnet IP

Infinitum Aircore EC+ motors support BACnet MS/TP. BACnet MS/TP utilizes RS485 as the physical layer. RS485 is a serial interface that follows the EIA/TIA-485 standards. Infinitum BACnet operation allows communication baud rates from 9600 to 115200 bits/sec. The interface is a differential signal, electrically isolated. It allows up to 32 devices on a segment, with a maximum cable length of 1000m. This EIA-485 network requires a terminating resistor at each end of the main bus. Infinitum Aircore EC+ motors include the terminating resistor.

Figure 1. BACnet MS/TP is one of the VFD and I/O options (“B”).

4. BACnet Module: Installation

BACnet is a factory configured option, though Infinitum service technicians can upgrade
a field installed motor to support it. BACnet functionality is provided by a BACnet module that is installed on the Aircore EC+ CIM (Communication Interface Module) board.

The BACnet module is BTL certified. PICS is in appendix.

See Figure 3.

The BACnet module is installed in the CIM below. For reference, the STAT on the screen print on the corner of the BACnet module faces the terminal strip. See Figure 4.

Note: If the BACnet module is installed in the incorrect orientation
this could cause permanent damage to the module

5. BACnet Module, Field Wiring

Like Modbus, BACnet uses EIA-485 signaling. All control signals are available on the terminal strip of the CIM board. See Figure 5 (Pin label 7) for the EIA-485 connections on the CIM board terminal strip. The following details should be followed for EIA networks:

Shielded cables should be used with at least one ground wire and twisted signal wires
Cable runs should be laid separately from power cables if possible
The network should be grounded, preferably at the same ground connection. Cable shields should be connected at each motor (but not to ground)
Termination resistance should be provided at each end of the cable run

6. Terminating Resistor

RS485 based networks require termination at both ends of the main bus. Infinitum motors provide this termination using a DIP switch that connects a 120 Ohm resistor to the serial line. This DIP switch placement is indicated in the drawing in Figure 5 (Identifier 8).

7. BACnet Module, Programming

BACnet networks require each device to have a unique address so they can be individually addressed by the BACnet master. Another BACnet parameter that must be established is the Baud rate. Infinitum provides an Installer link to the BACnet Network Parameter Utility (NPU) Tool, which can be used to change the address (Instance) and baud rate of each motor on the BACnet network. The tool is available on the Infinitum website (link) and as a link on I-con, the Infinitum motor control tool. See Figure 6.

Users will need internet access to utilize this link. The link is a Zip file. You should
extract all the files then run the NPU.exe file to start the NPU utility.

8. NPU Tool

BACnet networks require each device to have a unique address so The Infinitum Network Parameter Utility tool can be downloaded via the links above. Once downloaded, the tool uses a USB connection from a laptop to the CIM board to communicate to the installed BACnet module. See Figure 5. CIM terminal strip connections for the location of the Micro-USB port to use with NPU.

Once NPU is downloaded, connect a USB to Micro-USB cable to the port indicated above. Power on the motor and start the NPU program. The screen below should appear, Figure 7.