background image

Automation Components, Inc.

2305 Pleasant View Road  |  Middleton, WI 53562

Phone:

 1-888-967-5224  |  

Website:

 workaci.com

Page 1

Version: 2.0

I0000927

BACnet / Modbus DUCT SERIES

Installation & Operation Instructions

Phone:

 1-888-967-5224

Website:

 workaci.com

GENERAL INFORMATION

The BACnet MS/TP / Modbus RTU Duct Series sensor 
is designed for use with electronic controllers in 
commercial heating and cooling building manage-
ment systems. The ACI BACnet MS/TP /Modbus RTU 
Duct Series sensor can be ordered to monitor 
temperature, RH, or temp/RH in commercial HVAC 
ductwork. It uses BACnet MS/TP or Modbus RTU for 
physical connection to a BAS or controller, has dip 
switches to set addresses and baud rate, parity and 
stop bits (Modbus RTU only) and has on board 
end-of-line termination. There is no analog output.

WIRING INSTRUCTIONS

The BACnet/Modbus Duct Series temperature 
sensor has a depluggable terminal block located on 
the front of the PCB. For ease of wiring, we 
recommend removing the block, wiring, and 
reattaching before mounting. 16 to 22 AWG two 
conductor shielded cable is recommended for 
powering the sensors. 

ACI recommends using Belden 3105 or compatible 
cable for RS-485 communication wiring. This wire has 
120 ohm input impendence. The terminal blocks 
allow for (1) or (2) wires to be connected in each 
position for daisy chaining. Daisy chain the RS-485 
wiring and do not use “Star” or “T” wiring. Avoid 
running communication wires next to AC line voltage 
wires. These can be sources of noise that can affect 
signal quality.

PRECAUTIONS
•  Remove power before wiring. Never connect 

or disconnect wiring with power applied.

•  It is recommended you use an isolated 

UL-listed class 2 transformer when powering 
the unit with 24 VAC. Failure to wire the devices 
with the correct polarity when sharing 
transformers may result in damage to any 
device powered by the shared transformer. 

FIGURE 1: 

ENCLOSURE 

DIMENSIONS

EURO (-EH): RH and RH/TEMP.

PLASTIC BOX (-PB): TEMP. ONLY

1.90"

(48.28 mm)

4.30"

(109.22 mm)

3.80"

(96.56 mm)

3.60"

(91.44 mm)

2.25"

(57.15 mm)

1.51"

(38.25 mm)

3.01"

(76.51 mm)

10.05"

(255.32 mm)

2.12"

(53.72 mm)

4.79"

(121.55 mm)

2.35"

(59.80 mm)

Summary of Contents for BACnet Series

Page 1: ...we recommend removing the block wiring and reattaching before mounting 16 to 22 AWG two conductor shielded cable is recommended for powering the sensors ACI recommends using Belden 3105 or compatible cable for RS 485 communication wiring This wire has 120 ohm input impendence The terminal blocks allow for 1 or 2 wires to be connected in each position for daisy chaining Daisy chain the RS 485 wirin...

Page 2: ...ings followthesetips The sensor should be mounted in the middle of the duct where air circulation is well mixed no stratification and not blocked by obstructions Stratification and obstructions can cause sensing errors An example is downstream from a heating or coolingcoil Duct probe should be placed 3 to 4 duct segments down from any bend or obstructions and away from 90 bends Mount the sensor on...

Page 3: ...es are allowed to send and receive tokens on the MSTP network ACI s Modbus RTU sensors are slave devices Only one master is connected to the bus and several slave nodes are connected to the same trunk The Master initiates communication The slave nodes only respond to a request from the Master Slave nodes do not communicate with each other Each branch must have all devices connected with connected ...

Page 4: ... INFORMATION One LED indicates four statuses Solid green shows that power is good but no data is transmitting A solid Amber indicates that auto baud is set and no data has been received to set a baud rate Green Amber flashing indicates data is being transmitted or received Solid Red LED status indicates an error state usually loss of communication on the network If BACnet is the selected protocol ...

Page 5: ...Sensor objects AI0 and AI1 a test mode can be set by writing the Boolean value true to the out of service property Then the present value can be set to any valid test value the user requires This allows a user to test reactions to specific values returned by this device DEVICE LOCATION The device location is optional but is intended to allow for further definition of the device s location The devi...

Page 6: ...e as in the Master device configuration ACI s Modbus RTU sensors utilize 8 data bits during communication exchange Parity and stop bit selection is performed via the SW4 switch located on the board Dipswtiches 1 and 2 are adjusted to select the parity and stop bits see TABLE 6 Where 0 is OFF and 1 is ON If BACnet protocol is selected these dipswitches are irrelevant TEST MODE Modbus RTU There are ...

Page 7: ...ature Units 0 2 3 1001 1002 9001 Thru 9016 9017 Thru 9048 9049 Thru 9080 Temperature Offset Value Tenths Signed Integer User can set an offset that will be added to Temperature sensor and reflected in IR3 Range of 5 0 to 5 0 degrees Celsius degrees Kelvin 9 0 to 9 0 degrees Fahrenheit For example writing 16 would add an offset of 1 6 degrees Relative Humidity Offset Tenths User can set an offset t...

Page 8: ...able 4 seconds BACnet MS TP or Modbus RTU Field Selectable EIA RS 485 0 to 127 0 Default Must be changed if Modbus RTU is selected protocol Field Selectable Auto Baud Default BACnet Only 9600 19200 38400 57600 76800 115200 Field Selectable 1035000 Address example Address 127 1035127 Field Configurable None Even Odd Field Selectable 1 or 2 Field Selectable 8 Screw Terminal Blocks 16 AWG 1 31 mm2 to...

Reviews: