Unitronics GW-BAC1 User manual

GW-BAC1
BACnet Gateway
User Guide
For Interfacing Unitronics PLCs
To Building Automation Systems:
BACnet MS/TP, BACnet/IP, Modbus/TCP.
The information in this document reflects products at the date of printing. Unitronics reserves the right, subject to all applicable laws, at any time, at its sole discretion, and without notice, to discontinue or change
the features, designs, materials and other specifications of its products, and to either permanently or temporarily withdraw any of the forgoing from the market.
All information in this document is provided "as is" without warranty of any kind, either expressed or implied, including but not limited to any implied warranties of merchantability, fitness for a particular purpose, or
non-infringement. Unitronics assumes no responsibility for errors or omissions in the information presented in this document. In no event shall Unitronics be liable for any special, incidental, indirect or
consequential damages of any kind, or any damages whatsoever arising out of or in connection with the use or performance of this information.
The tradenames, trademarks, logos and service marks presented in this document, including their design, are the property of Unitronics (1989) (R"G) Ltd. or other third parties and you are not permitted to use
them without the prior written consent of Unitronics or such third party as may own them
DOC01002-A5 10/14

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Certifications
BTL MARK –BACNET TESTING LABORATORY
The BTL Mark on GW-BAC1 is a symbol that indicates that a product has passed a
series of rigorous tests conducted by an independent laboratory which verifies that
the product correctly implements the BACnet features claimed in the listing.
The mark is a symbol of a high-quality BACnet product.
Go to http://www.bacnetinternational.net/btl/ for more information about the
BACnet Testing Laboratory.

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TABLE OF CONTENTS
1Introduction................................................................................................................................................................5
1.1 GW-BAC1 Gateway .............................................................................................................................................5
1.2 Record Identification Data ..................................................................................................................................5
1.3 Technical Support ...............................................................................................................................................5
2Interfacing GW-BAC1 to Devices ................................................................................................................................6
2.1 GW-BAC1 Showing Connection Ports .................................................................................................................6
2.2 Connecting a Unitronics PLC to the GW-BAC1 via Modbus RS-485....................................................................7
2.2.1 Biasing the Modbus RS-485 Network ...........................................................................................................8
2.2.2 End of Line Termination Switch for the Modbus RS-485 port on the GW-BAC1 ..........................................9
2.3 BACnet MS/TP Field Devices: Wiring Field Port to RS-485 Network ................................................................10
2.4 Connecting Power to GW-BAC1........................................................................................................................11
3Creating configuration file and configurating the PLC ....................................................................................... 12
3.1 UniBACnet configurator....................................................................................................................................12
3.2 PLC configuration example. ..............................................................................................................................18
4ChangING the GW-BAC1 IP Address ..................................................................................................................21
4.1 Connect the PC to GW-BAC1 via the Ethernet Port..........................................................................................21
4.2 BACnet/IP: Setting IP Address for Field Network .............................................................................................22
Appendix A. Troubleshooting ................................................................................................................................... 23
Check Wiring and Settings.....................................................................................................................23Appendix A.1.
Diagnostic Capture ................................................................................................................................24Appendix A.2.
LED Diagnostics for Modbus RTU Communications Between GW-BAC1 and Devices..........................27Appendix A.3.
Appendix B. Reference ............................................................................................................................................. 28
Specifications.........................................................................................................................................28Appendix B.1.
Compliance with UL Regulations...........................................................................................................28Appendix B.2.

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LIST OF FIGURES
Figure 1: BACnet board.......................................................................................................................................................6
Figure 2: Power and RS-485 Connections...........................................................................................................................7
Figure 3: Modbus RS-485 Biasing Switch on the GW-BAC1..............................................................................................8
Figure 4: Modbus RS-485 End-Of-Line Termination Switch on the GW-BAC1 ...................................................................9
Figure 5: Connection from GW-BAC1 to RS-485 Field Network .......................................................................................10
Figure 6: RS-485 EOL Switch .............................................................................................................................................10
Figure 7: Required current draw for the GW-BAC1..........................................................................................................11
Figure 8: Power Connections............................................................................................................................................11
Figure 9: Tools menu on VisiLogic ....................................................................................................................................12
Figure 10: Tools menu on UniLogic ..................................................................................................................................12
Figure 11: BACnet Connection MS/TP Screen ..................................................................................................................13
Figure 12: BACnet Connection IP Screen ..........................................................................................................................13
Figure 13: BACnet Nodes Screen .....................................................................................................................................14
Figure 14: BACnet Map descriptors Screen ......................................................................................................................14
Figure 15: Modbus connection RTU Screen .....................................................................................................................15
Figure 16: Modbus connection IP Screen .........................................................................................................................15
Figure 17: Finish Screen....................................................................................................................................................16
Figure 18: File Transfer Screen .........................................................................................................................................17
Figure 19: File menu .........................................................................................................................................................17
Figure 20: MODBUS RTU configuration ............................................................................................................................18
Figure 21: Example of COM initialize................................................................................................................................18
Figure 22: Example of Modbus configuration ..................................................................................................................19
Figure 23: Example of MODBUS TCP/IP configurator.......................................................................................................19
Figure 24: Example of TCP/IP card and socket initialize ...................................................................................................19
Figure 25: Example of TCP/IP card and socket initialize ...................................................................................................20
Figure 26: Example of MODBUS Command......................................................................................................................20
Figure 27: Ethernet Port Location.....................................................................................................................................21
Figure 28: PC IP configuration ..........................................................................................................................................21
Figure 29: Changing IP Address via FST Web GUI .............................................................................................................22
Figure 30: Ethernet Port Location.....................................................................................................................................24
Figure 31: Diagnostic tool –device selection ...................................................................................................................24
Figure 32: Diagnostic selection.........................................................................................................................................25
Figure 33: Diagnostic tool –start diagnostic ....................................................................................................................25
Figure 34: Diagnostic tool –diagnostic test complete ......................................................................................................26
Figure 35: Diagnostic LEDs................................................................................................................................................27
Figure 36: Specifications...................................................................................................................................................28

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1INTRODUCTION
1.1 GW-BAC1 Gateway
The GW-BAC1 is an external, high performance Building Automation multi-protocol gateway that has been
preprogrammed for enabling Unitronics products (hereafter called “device”) to various building automation
protocols. These protocols include BACnet®
1
MS/TP and BACnet/IP
2
. Configuration for the various protocols is
done via Unitronics configuration tool UniBACnet Configurator.
1.2 Record Identification Data
Each GW-BAC1 has a unique serial number located on the underside of the unit. This number should be
recorded, as it may be required for technical support.
1.3 Technical Support
For technical support and questions concerning setting up the GW-BAC1 to work with a Unitronics PLC
(e.g. Vision, UniStream etc.) please contact Unitronics technical support at [e-mail] .
1
BACnet is a registered trademark of ASHRAE

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2INTERFACING GW-BAC1 TO DEVICES
2.1 GW-BAC1 Showing Connection Ports
Figure 1: BACnet board

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2.2 Connecting a Unitronics PLC to the GW-BAC1 via Modbus RS-485
GW-BAC1 6 Pin Phoenix connector for RS-485 Device
The 6 pin Phoenix connector is the same for GW-BAC1.
Pins 1 through 3 are for Modbus RS-485 devices.
oThe RS-485 GND (Pin 3) is not typically connected.
Pins 4 through 6 are for power. Do not connect power (wait until Section 3.4).
Figure 2: Power and RS-485 Connections
Device Pins
GW-BAC1 Pin #
Pin assignment
Pin RS-485 +
Pin 1
RS-485 +
Pin RS-485 -
Pin 2
RS-485 -
Pin GND
Pin 3
RS-485 GND
Power In (+)
Pin 4
V +
Power In (-)
Pin 5
V -
Frame Ground
Pin 6
FRAME GND

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2.2.1 Biasing the Modbus RS-485 Network
An RS-485 network with more than one device needs to have biasing to ensure proper communication.
The biasing needs to be done on one device.
The GW-BAC1 has 530 Ohm resistors that can be used to set the biasing. The GW-BAC1’s default positions
from the factory for the Biasing jumpers are OFF.
The OFF position is when the 2 RED biasing jumpers straddle the 4 pins closest to the outside of the board of the GW-
BAC1. See Error! Reference source not found..
Only turn biasing ON:
oIF the BMS cannot see more than one device connected to the GW-BAC1
oAND you have checked all the settings (Modbus COM settings, wiring, and DIP switches).
To turn biasing ON, move the 2 RED biasing jumpers to straddle the 4 pins closest to the inside of the
board of the GW-BAC1.
Figure 3: Modbus RS-485 Biasing Switch on the GW-BAC1
RS-485 Bias Switch

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2.2.2 End of Line Termination Switch for the Modbus RS -485 port on the GW-BAC1
On long RS-485 cabling runs, the RS-485 trunk must be properly terminated at each end.
The GW-BAC1 has an End Of Line (EOL) blue jumper. The default setting for this Blue EOL switch is OFF
with the jumper straddling the pins closest to the inside of the board of the GW-BAC1.
oOn short cabling runs the EOL switch does not to need to be turned ON.
If the GW-BAC1 is placed at one of the ends of the trunk, set the blue EOL jumper to the ON position
straddling the pins closest to the outside of the board of the GW-BAC1.
Always leave the single Red Jumper in the A position (default factory setting).
Modbus RS-485 EOL Switch
Leave in A Position
Figure 4: Modbus RS-485 End-Of-Line Termination Switch on the GW-BAC1

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2.3 BACnet MS/TP Field Devices: Wiring Field Port to RS-485 Network
Connect the BACnet MS/TP RS-485 network wires to the 3-pin RS-485 connector on GW-BAC1 as shown
below in Error! Reference source not found..
oThe RS-485 GND (Pin 3) is not typically connected.
See Section 3for information on connecting to BACnet/IP network.
If the GW-BAC1 is the last device on the BACnet MS/TP trunk, then the End-Of-Line Termination
Switch needs to be enabled (Error! Reference source not found.).
oThe default setting from the factory is OFF (switch position = right side).
oTo enable the EOL Termination, turn the EOL switch ON (switch position = left side).
Figure 5: Connection from GW-BAC1 to RS-485 Field Network
Figure 6: RS-485 EOL Switch
BMS RS-485
Wiring
GW-BAC1
Pin #
Pin
Assignment
RS-485 +
Pin 1
RS-485 +
RS-485 -
Pin 2
RS-485 -
-
Pin 3
RS-485 GND
G
-
+
End-of-Line Switch

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2.4 Connecting Power to GW-BAC1
Apply power to GW-BAC1 as show below in Error! Reference source not found.. Ensure that the power supply
used complies with the specifications provided in Appendix B.1.
GW-BAC1 accepts either 9-30VDC or 12-24 VAC on pins 4 and 5.
oThe “Frame Ground” (pin 6) is not typically connected.
Power Requirement for GW-BAC1 at 9V through 30 VDC or 12-24 VAC
Current Draw Type
GW-BAC1 Family
12VDC/VAC
24VDC/VAC
30VDC
FPC –N34 (Typical)
170mA
100mA
80mA
FPC –N34 (Maximum)
240mA
140mA
100mA
Note: These values are ‘nominal’ and a safety margin should be added to the power supply of the host system. A
safety margin of 25% is recommended.
Figure 7: Required current draw for the GW-BAC1
Figure 8: Power Connections
Power to GW-
BAC1
GW-BAC1
Pin #
Pin
Assignment
Power In (+)
Pin 4
V +
Power In (-)
Pin 5
V -
Frame Ground
Pin 6
FRAME GND

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3CREATING CONFIGURATION FILE AND CONFIGURATING THE PLC
3.1 UniBACnet configurator
UniBACnet configurator is a tool provided Unitronics that allows the user to create the configuration file for the GW-
BAC1 easily. Once created, the configuration file should be downloaded to the GW-BAC1 in order to enable it to
communicate with the Unitronics PLC. The UniBACnet configurator can be launched from both the VisiLogic and
UniLogic programing applications Tools menu.
Figure 9: Tools menu on VisiLogic
Figure 10: Tools menu on UniLogic

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Configuration file creation steps
BACnet Connection: Use this menu for setting up the BACnet Gateway communication parameters.
First you must choose the type of BACnet Protocol: MS/TP (Serial) or IP.
Figure 11: BACnet Connection MS/TP Screen
Figure 12: BACnet Connection IP Screen

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BACnet Device instance: Here you will add all the BACnet slave devices.
Figure 13: BACnet Nodes Screen
The Device instance must correspond with the ID given to the device. To assign an ID to the device please follow
the configuration manual of the device.
BACnet Map Descriptions: Here you will add the Inputs/Outputs/values to be read and or write in each node,
select the format –Int16. Uint16, Int32, Uint32-, Object ID, scan interval and function type.
Figure 14: BACnet Map descriptors Screen

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Note that the read function will let you read and write while write function will only let you write.
Read and write block continuous means that the data will be read and write continuously.
Write block on change means that only when there is change in the data, it will be written.
Modbus Connection: Here the user will configure the Modbus connection to the PLC.
First the user must select between Modbus protocol: RTU or TCP/IP, then the corresponding configuration.
Figure 15: Modbus connection RTU Screen
Figure 16: Modbus connection IP Screen

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Finish: This window will show the addressing map of the data to be read/write from/to the device -to be use
in VisiLogic ladder logic- and will let you export the configuration file that you will download to the GW-BAC1
via the GUI browser.
Figure 17: Finish Screen
Once you have created the configuration file, it has to be downloaded to the GW-BAC1 unit according to
the following instructions.
a. Connect a standard CAT5 Ethernet cable (Straight through or Cross-Over) between the PC and GW-
BAC1
b. The Default IP Address of GW-BAC1 is 192.168.1.24, Subnet Mask is 255.255.255.0. If the PC and
GW-BAC1 are on different IP Networks, assign a static IP Address to the PC on the 192.168.1.xxx
network
c. Go to > >
d. Right-click on Local Area Connection > Properties
e. Highlight >
f. Select: Use the following IP address
g. Click twice

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h. After setting your PC to be on the same subnet as the GW-BAC1, open a web browser on your PC
and enter the IP address of the GW-BAC1; the default address is 192.168.1.24.
i. If IP address of the GW-BAC1 has been changed by previous configuration, down load FieldServer
Toolbox to discover unknown IP address of the GW-BAC1.
http://www.fieldserver.com/docs/downloads/FieldServer-Toolbox.zip
j. The FST Web GUI page will be presented.
From the FST Web GUI’s landing page, click on “Setup” to expand the navigation tree and then select “File transfer”
to access the IP Settings menu. (Error! Reference source not found.)
Figure 18: File Transfer Screen
k. Select browse and look for the CSV file you just created.
l. Click on submit button. The download process should take a couple of seconds.
m. To finish please click on system restart.
The File menu will let you save the current configuration or open a previously saved one.
Figure 19: File menu

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3.2 PLC configuration example.
Please note: The following section provides an example of the required configuration using the Vision570 PLC.
The configuration required for your specific application may require some changes.
VisiLogic includes further examples for BACNet/Modbus RTU and BACnet/Modbus TCP_IP.
In all setting the PLC must be configured as a MODBUS master.
Depending on the MODBUS protocol the user has chosen, the PLC needs to be configured as MODBUS RTU or
MODBUS TCP_IP master.
Figure 20: MODBUS RTU configuration
Figure 21: Example of COM initialize

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Figure 22: Example of Modbus configuration
Figure 23: Example of MODBUS TCP/IP configurator
Figure 24: Example of TCP/IP card and socket initialize

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Figure 25: Example of TCP/IP card and socket initialize
After the initial configuration, add the proper Modbus commands to read/write data using the addresses table
obtained in the finish screen of the UniBACnet Configurator.
Figure 26: Example of MODBUS Command