Contemporary Control Systems BASremote User Manual

BASR

Versatile Building Automation Appliance

BAS Remote

User Manual

# TD040300-0MF

(for firmware version 3.1.x)

Contemporary Control Systems, Inc.

Tel:

[phone]

2431 Curtiss Street

Fax:

[phone]

Downers Grove, Illinois 60515 USA

E-mail:

[e-mail]

WWW:

http://www.ccontrols.com

Contemporary Controls Ltd

Tel:

[phone]

14 Bow Court

Fax:

[phone]

Fletchworth Gate

E-mail:

[e-mail]

Coventry CV5 6SP UK

WWW:

http://www.ccontrols.co.uk

Contemporary Controls Ltd

Tel:

[phone]

14 Bow Court

Fax:

[phone]

Fletchworth Gate

E-mail:

[e-mail]

Coventry CV5 6SP UK

WWW:

http://www.ccontrols.eu

Contemporary Controls GmbH

Tel:

[phone]

Fuggerstraße 1 B

Fax:

[phone]

D-04158 Leipzig Deutschland

E-mail:

[e-mail]

WWW:

http://www.ccontrols.eu

WARNING — This is a Class A product as defined in EN55022.

In a domestic environment this product may cause radio interference

in which case the user may be required to take adequate measures.

Trademarks

Contemporary Controls and CTRLink are registered trademarks of Contemporary Control Systems, Inc.
BACnet is a registered trademark of the American Society of Heating, Refrigerating and Air-Conditioning
Engineers, Inc. Powered by Sedona Framework is a trademark of Tridium, Inc. Other product names
may be trademarks or registered trademarks of their respective companies.

Copyright

© Copyright 2012, by Contemporary Control Systems, Inc. All rights reserved. No part of this publication
may be reproduced, transmitted, transcribed, stored in a retrieval system, or translated into any language
or computer language, in any form or by any means, electronic, mechanical, magnetic, optical, chemical,
manual, or otherwise, without the prior written permission of:

Disclaimer

Contemporary Control Systems, Inc. reserves the right to make changes in the specifications of the
product described within this manual at any time without notice and without obligation of Contemporary
Control Systems, Inc. to notify any person of such revision or change.

TD040300-0MF

2

1 Table of Contents

1 TABLE OF CONTENTS ..................................................................................................... 3

2 INTRODUCTION ................................................................................................................. 6

2.1 Features and Benefits ...................................................................................................... 8

2.2 Software .......................................................................................................................... 9

2.3 Product Image (Master Module) ..................................................................................... 9

3 SPECIFICATIONS ............................................................................................................. 10

3.1 Universal Input/Outputs — Channels 1–6 .................................................................... 10

3.2 Relay Outputs — Channels 7–8 .................................................................................... 10

3.3 Communications ........................................................................................................... 10

3.4 Protocol Compliance ...................................................................................................... 11

3.5 Power Requirements ..................................................................................................... 11

3.6 General Specifications .................................................................................................. 11

3.7 LED Indicators ............................................................................................................... 12

3.8 Electromagnetic Compatibility ..................................................................................... 12

3.9 Field Connections ......................................................................................................... 13

3.10 Ordering Information .................................................................................................... 13

3.11 Dimensional Drawing ................................................................................................... 14

3.12 PICS Statement ............................................................................................................. 15

4 INSTALLATION ................................................................................................................ 16

4.1 Power Supply ................................................................................................................ 16

4.1.1 Power Supply Precautions ........................................................................................ 17

4.1.2 Limited Power Sources ............................................................................................. 17

4.2 Connecting Expansion Equipment ................................................................................ 18

4.2.1 BAS Remote Expansion Module Connections ......................................................... 18

4.2.2 Modbus Serial Bus Connections ............................................................................... 19

4.2.3 Cabling Considerations ............................................................................................. 20

5 FIELD CONNECTIONS .................................................................................................... 21

5.1 Sample BAS Remote Wiring Diagram ......................................................................... 21

5.2 Thermistors ................................................................................................................... 22

5.3 Contact Closure ............................................................................................................. 22

5.4 Pulse Inputs ................................................................................................................... 24

5.5 Analog Input ................................................................................................................. 25

5.6 Analog Output ............................................................................................................... 26

TD040300-0MF

3

6 OPERATION ...................................................................................................................... 27

6.1 General Considerations ................................................................................................. 27

6.1.1 Ethernet Port on the Master Module ......................................................................... 27

6.1.2 LEDs ......................................................................................................................... 27

6.1.3 Accessing and Configuring the Web Server on the Master Unit .............................. 28

6.1.4 Web Server Screen Overview ................................................................................... 35

6.1.5 On-Screen Help ......................................................................................................... 36

6.2 Input/Output Channels (I/O) ....................................................................................... 37

6.2.1 Universal I/Os ........................................................................................................... 37

6.2.2 Relay Outputs ............................................................................................................ 37

6.3 Channel Configuring ..................................................................................................... 38

6.3.1 Analog Voltage Input Configuring ........................................................................... 38

6.3.2 Analog Voltage Output Configuring ........................................................................ 39

6.3.3 Binary Input Configuring .......................................................................................... 40

6.3.4 Current Input Configuring ........................................................................................ 41

6.3.5 Current Output Configuring ...................................................................................... 42

6.3.6 Thermistor Input Configuring ................................................................................... 43

6.3.7 Pulse Input Configuring ............................................................................................ 44

6.3.8 Relay Output Configuring ......................................................................................... 46

6.4 Channel Forcing ............................................................................................................ 47

6.4.1 Analog Input Forcing ................................................................................................ 47

6.4.2 Binary Input Forcing ................................................................................................. 48

6.4.3 Current Input Forcing ............................................................................................... 48

6.4.4 Thermistor Input Forcing .......................................................................................... 49

6.4.5 Relay Output Forcing ................................................................................................ 49

6.5 Instance Numbers.......................................................................................................... 50

6.6 Flash File System and Custom Web Pages ................................................................... 50

6.7 Web Services ................................................................................................................ 51

6.8 Set Time ........................................................................................................................ 51

7 APPENDIX .......................................................................................................................... 52

7.1 Troubleshooting Ethernet Connectivity of the Master Unit ......................................... 52

7.2 BACnet Object Model .................................................................................................. 52

7.2.1 Device ....................................................................................................................... 52

7.2.2 Analog Input .............................................................................................................. 53

7.2.3 Analog Output ........................................................................................................... 53

7.2.4 Analog Value ............................................................................................................ 53

7.2.5 Binary Input .............................................................................................................. 54

7.2.6 Binary Output ............................................................................................................ 54

TD040300-0MF

4

7.2.7 BIBBs ........................................................................................................................ 55

7.3 Sedona for Control ........................................................................................................ 57

7.3.1 Getting Started with a Sedona Tool .......................................................................... 57

7.3.2 Virtual Points ............................................................................................................ 59

7.4 Modbus Server Operation ............................................................................................. 60

7.4.1 Modbus Register Organization ................................................................................. 61

7.4.2 Modbus Function Codes ........................................................................................... 64

7.5 Mapping Modbus Variables to BACnet/IP ................................................................... 64

7.5.1 General Mapping Principles...................................................................................... 64

7.5.2 Mapping Scheme ...................................................................................................... 64

7.5.3 Project Builder .......................................................................................................... 65

7.5.4 Viewing the Mapping Status in the BAS Remote .................................................... 71

7.6 Modbus Utility .............................................................................................................. 72

7.7 Linux License................................................................................................................ 74

TD040300-0MF

5

2 Introduction

The BAS Remote Master provides the ultimate in flexibility. It can be used for
Expansion I/O at remote locations where an Ethernet connection exists. Its built-in
router and gateway capability addresses unique integration needs where more than one
communications protocol is involved. It can function as a controller with its resident
Sedona Virtual Machine. Powered by a Linux engine, the BAS Remote Master can
operate as BACnet/IP or Modbus TCP remote I/O, Sedona controller, Modbus Serial to
Modbus TCP router, Modbus Serial to BACnet gateway, and Modbus master to
attached Modbus slaves – all at the same time. The BAS Remote also supports web
services. You can customize the unit via custom web pages that utilize special java
applets provided in the device. A 10/100 Mbps Ethernet port allows connection to IP
networks and popular building automation protocols such as Modbus TCP, BACnet/IP,
and Sedona SOX. Six universal I/O points and two relay outputs can be configured
through resident web pages using a standard web browser and without the need of a
special programming tool. A 2-wire Modbus serial port can greatly expand the I/O count
with built-in routing to Modbus TCP clients. If BACnet mapping is preferred, the unit
incorporates a Modbus serial to BACnet/IP gateway. Additional universal I/O can be
achieved with the simple addition of BAS Remote Expansion modules. The BAS
Remote Master PoE has the same capabilities as the BAS Remote Master except it is
powered over the Ethernet connection — thereby providing a “One Cable Solution.”

Both the BAS Remote Master and BAS Remote Expansion modules have the same
I/O capability. Six universal input/output points are provided on each module.
Depending upon configuration, each unit can accommodate a contact closure from a
digital point, a thermistor, voltage or current analog input from a field transmitter or
supervisory controller. Analog inputs can range from 0–5 VDC, 0–10 VDC or 0–20 mA.
Inputs can be scaled to accommodate ranges such as 1–5 VDC, 2–10 VDC, and 4–20
mA. Input point resolution is 10-bits.

Type II and III 10 kΩ thermistor calibration curves are resident in the BAS Remote. Single­point calibration of temperature is accomplished using the internal web server. Inputs can
accept pulse trains in the range of 0–40 Hz (50% duty cycle) to measure flow rates.

Analog outputs can be 0–10 VDC or 0–20 mA. However, scaling for 2–10 V, 0–5 V,
1–5 V and 4–20 mA is possible. LED indicators identify the state of I/O points. Output
point resolution is 12 bits.

There are two relay outputs available with both normally open (NO) and normally closed
(NC) contacts. The relay output rating is 30 VAC/VDC, 2A.

There are two non-isolated 2-wire EIA-485 Expansion ports on the Master module. The
downstream port (DN) is intended for Expansion modules while the Modbus (MB) port
functions as either a Modbus TCP router or Modbus serial to BACnet gateway — allowing
for the attachment of Modbus 2-wire or 3-wire EIA-485 serial devices. On BAS Remote
Expansion modules, the two ports are marked UP and DN, and are dedicated for
communication with the BAS Remote Master module and other Expansion modules.

All field connectors are removable — making field replacement of units quick and simple.
A single RJ-45 shielded connector provides the 10/100 Mbps twisted-pair Ethernet

connection. The unit supports auto-negotiation of data rate and duplex. A resident web

TD040300-0MF

6

server facilitates commissioning and troubleshooting. Configuration is accomplished via
Ethernet. Java must be enabled in the browser used to access the BAS Remote.

Power for the BAS Remote can be derived from a 24 VAC Class 2 transformer capable
of delivering 17 VA or from a 24 VDC power supply capable of at least 10 W. Since the
unit incorporates a half-wave rectified power supply, attached I/O points and the power
supply can share a common ground. Therefore, the BAS Remote can be powered by
the same control transformer used to power other half-wave rectified control equipment.
The BAS Remote can be DIN-rail mounted into a control panel. If panel mounting is
required, use the supplied mounting tabs.

The BAS Remote conforms to the BACnet/IP standard and therefore allows field I/O to
be directly accessed via Ethernet without the need of a router. A standard web browser
with Java enabled is used for commissioning and troubleshooting. The BAS Remote
adheres to the BACnet Application Specific Controller (B-ASC) profile.

TD040300-0MF

7

2.1 Features and Benefits

Versatile Control Device — remote I/O, router, gateway and controller

 Web-page configuration
 BACnet/IP Remote I/O
 Modbus TCP Remote I/O
 Modbus Serial to Modbus TCP Router
 Modbus Serial to BACnet/IP Gateway
 Modbus Master to Attached Modbus Slaves
 Powered by Sedona Controller
 Power over Ethernet (PoE)
 Java Applets for customisable web pages
 Web Services

Flexible Input/Output — expandable by adding modules

 Six universal input/output points — web-page configurable
 Two relay outputs
 Thermistor, voltage, current, contract closure and pulse inputs
 Voltage, current and relay outputs
 2-wire Modbus Serial Expansion port
 2-wire Expansion port for up to three Expansion modules

TD040300-0MF

8

I/O Ports 1–3

I/O Ports 4–6

Reset

24 V Loop Supply

Input Power

Output Relays

Ethernet Port

DIN-rail Release Tab

Expansion Ports

2.2 Software

The provided CD-ROM contains:

 This User Manual
 A copy of the Installation Guide that is packaged with the product
 Additional information of interest

2.3 Product Image (Master Module)

Figure 1 — BAS Remote Master Module Main Features

TD040300-0MF

9

Configured As

Limits

Analog Input

0–5 VDC, 0–10 VDC or 0–20 mA scalable by user. 10-bit resolution.
Input impedance 100 kΩ on voltage and 250 Ω on current.

Temperature Input

Type II or Type III thermistors
+40°F to +110°F (+4.4°C to +44°C)

Contact closure input

Excitation current 2 mA. Open circuit voltage 24 VDC.
Sensing threshold 0.3 VDC. Response time 20 ms.

Pulse input

0–10 VDC scalable by user. User adjustable threshold.
40 Hz maximum input frequency with 50% duty cycle.

Analog Output

0–10 VDC or 0–20 mA scalable by user. 12-bit resolution.
Maximum burden 750 Ω when using current output.

Limits

Form “C” contact with both NO and NC contacts available.
30 VAC/VDC 2 A. Class 2 circuits only.

Protocol

Data Link and Physical Layers

BACnet/IP
— Master only

ANSI/IEEE 802.3 10/100 Mbps Ethernet.
10BASE-T, 100BASE-TX, auto-negotiation of speed and duplex.
Auto-MDIX. 100 m maximum segment length.
Default IP address is 192.168.92.68/24.

Modbus TCP
— Master only

Expansion Bus
(UP/DN)

Modified Modbus serial protocol. 2-wire non-isolated EIA-485

57.6 kbaud. Maximum segment length 100 m.

Modbus Serial
— Master only
(MB Bus)

Modbus serial ASCII or RTU protocol.
2-wire non-isolated EIA-485.

2.4, 4.8, 9.6, 19.2, 38.4, 57.6, 115.2 kbps.
Max segment length 100 m.
Jumper selectable bias and termination.

3 Specifications

3.1 Universal Input/Outputs — Channels 1–6

3.2 Relay Outputs — Channels 7–8

3.3 Communications

TD040300-0MF

10

Protocol

Compliance

BACnet/IP

ASHRAE 135-2008 annex J.
Application specific controller device profile B-ASC.

Modbus TCP

Modbus Application Protocol Specification V1.1b Dec. 28, 2006, Modbus.org.
Modbus Messaging on TCP/IP Implementation Guide V1.0b October 24, 2006,

Modbus.org.

Modbus serial

Modbus over Serial Line Specification and Implementation Guide V1.02 December
20, 2006, Modbus.org.

Item

Limits

Input power

Master module: 24 VAC/VDC ± 10%, 47–63 Hz, 17 VA
Master PoE module: 48 VDC ± 10% 10 W
Expansion module: 24 VAC/VDC ± 10%, 47–63 Hz, 17 VA

Loop supply

+24 VDC nom, 150 mA maximum

Item

Description

Protection

All inputs and outputs (except for relay outputs and communications ports) are
over-voltage protected up to 24 VAC and short-circuit protected.

Environmental

Operating temperature 0° to +60°C.
Storage temperature –40°C to +85°C.
Relative humidity 10 to 95%, non-condensing.

Weight

0.6 lbs. (0.27 kg).

3.4 Protocol Compliance

3.5 Power Requirements

3.6 General Specifications

TD040300-0MF

11

LED Indicator

Indication

I/O 1–6 configured as
Analog input

Green: > 1% of range, otherwise off

I/O 1–6 configured as
Temperature input

Green: sensor detected
Red: open

I/O 1–6 configured as
Contact input

Green: contact closed, otherwise off

I/O 1–6 configured as
Pulse input

Green: pulse sensed, otherwise off

I/O 1–6 configured as
Analog output

Green: commanded output
Red: expected output not within 40 mV on voltage or 0.2 mA on current

Status

Red: device in reset
Green flashing: booting up
Green: running application
Green flashing: Modbus serial activity after application is running —

Master only

Ethernet — Master
module only

Yellow: 10Mbps; flashes with activity
Green: 100 Mbps; flashes with activity

Network — Expansion
module only

Green flashing: Expansion bus activity

Standard

Test Method

Description

Test Levels

EN 55024

EN 61000-4-2

Electrostatic Discharge

6 kV contact

EN 55024

EN 61000-4-3

Radiated Immunity

10 V/m, 80 MHz to 1 GHz

EN 55024

EN 61000-4-4

Fast Transient Burst

1 kV clamp & 2 kV direct

EN 55024

EN 61000-4-5

Voltage Surge

1 kV L-L & 2 kV L-Earth

EN 55024

EN 61000-4-6

Conducted Immunity

10 V (rms)

EN 55024

EN 61000-4-11

Voltage Dips & Interruptions

1 Line cycle, 1–5 s @100% dip

EN 55022

CISPR 22

Radiated Emissions

Class A

EN 55022

CISPR 22

Conducted Emissions

Class B

CFR 47, Part 15

ANSI C63.4

Radiated Emissions

Class A

3.7 LED Indicators

3.8 Electromagnetic Compatibility

TD040300-0MF

12

Terminal

Power — Master Module*

Power — Expansion Module

HI

High AC or DC +

High AC or DC +

COM

AC or DC common

AC or DC common

Earth

Optional earthing connection

No connection

Model

Description

BASR-8M

BAS Remote Master with eight I/O points

BASR-8X

BAS Remote Expansion with eight I/O points

BASR-8M/P

BAS Remote Master PoE with eight I/O points

Terminal

Universal I/Os 1 – 3

I/O 1 A

Universal I/O point 1 high

I/O 1 B

Universal I/O point 1 low

I/O 2 A

Universal I/O point 2 high

I/O 2 B

Universal I/O point 2 low

I/O 3 A

Universal I/O point 3 high

I/O 3 B

Universal I/O point 3 low

Terminal

Universal I/Os 4 – 6

I/O 4 A

Universal I/O point 4 high

I/O 4 B

Universal I/O point 4 low

I/O 5 A

Universal I/O point 5 high

I/O 5 B

Universal I/O point 5 low

I/O 6 A

Universal I/O point 6 high

I/O 6 B

Universal I/O point 6 low

Terminal

Relay Outputs

OUT 8 NC

Output 8 normally-closed contact

OUT 8 C

Output 8 common

OUT 8 NO

Output 8 normally-open contact

OUT 7 NC

Output 8 normally-closed contact

OUT 7 C

Output 8 common

OUT 7 NO

Output 8 normally-open contact

Terminal

+24 VDC @ 150 mA Loop Supply

1

+24 VDC

2

+24 VDC

3

+24 VDC

4

+24 VDC

5

+24 VDC

6

+24 VDC

Terminal

Expansion Ports — Master Module

Terminal

Expansion Ports — Expansion Module

MB-D+

Modbus Serial Bus positive terminal

UP-D+

Upstream Expansion positive terminal

MB-D–

Modbus Serial Bus negative terminal

UP-D–

Upstream Expansion negative terminal

SC

Modbus signal common

SC

Not used

DN-D+

Downstream Expansion positive terminal

DN-D+

Downstream Expansion positive terminal

DN-D–

Downstream Expansion negative terminal

DN-D–

Downstream Expansion negative terminal

3.9 Field Connections

* BASR-M model only

3.10 Ordering Information

TD040300-0MF

13

3.11 Dimensional Drawing

Figure 2 — BAS Remote Dimensions

TD040300-0MF

14

3.12 PICS Statement

TD040300-0MF

15

4 Installation

The BAS Remote is intended to be mounted in an industrial enclosure or wiring closet
on 35-mm DIN-rail or panel-mounted with screws (not provided). The panel-mounting
tabs are packaged in a plastic bag within the shipping box. To use these tabs, Figure 3
illustrates how the two studs of each tab are press fitted into their respective holes in
opposing corners of the case.

Figure 3 — Attaching Panel-Mounting Tabs

4.1 Power Supply

The power source for the internal supply is applied via the three terminals labelled
Earth, COM, and HI. Earth allows external connection to earth if better EMC
compliance is needed. COM is for the power source return and also serves as the BAS
Remote common ground connection. Primary 24 VAC/VDC (± 10%) power is applied to
HI and COM. HI connects to a diode accomplishes half-wave rectified power — while
providing reverse input voltage protection.

Internally, the BAS Remote provides the 24 VDC loop supply to power external devices
attached as inputs to the BAS Remote — you do not need a separate loop supply.
Since the BAS Remote can source current via its analog outputs, an internal source of
24 VDC is provided for powering outputs. Collectively, the sum of input and output
power cannot exceed 150 mA.

Maximum current draw for any I/O channel is 20 mA — yielding a total draw of 120 mA
for all six channels. Analog output current sources from the same internal supply, so an
external source of 24 VDC is unneeded — but a return common is. Six +24 VDC pins
are present to serve external transmitters, so they do not need a separate loop supply.
However, the power supply must serve only its own BAS Remote module.

The BAS Remote requires 24 VDC or VAC from a source via a three-pin removable keyed
connector. The proper connections for various power options are shown in Figure 4.
Note that the BAS Remote Master PoE derives its power from the Ethernet cable and
therefore no internal connection exists for the HI pin on the input power connector.

The recommended size for power conductors is 16–18 AWG (solid or stranded). Ground
is directly connected to zero volts. Input connections are reverse-polarity protected.

NOTE: This device is intended for use with Class 2 circuits.

TD040300-0MF

16

Figure 4 — Power Options

WARNING: Powering devices can present hazards. Read the next two sections carefully.

4.1.1 Power Supply Precautions

Internally, the BAS Remote utilizes a half-wave rectifier and therefore can share the
same AC power source with other half-wave rectified devices. Sharing a common DC
power source is also possible. Sharing AC power with full-wave rectified devices is
NOT recommended. Full-wave rectified devices usually require a dedicated AC power
source that has a secondary elevated above ground. Both secondary connections are
considered HOT. AC power sources that power several half-wave devices have a
common secondary connection called COMMON, LO, or GROUND. This connection
might be tied to earth. The other side of the secondary is considered the HOT or HI
side of the connection. Connect the HOT side of the secondary to the HI input on the
BAS Remote and the LO side to COM on the BAS Remote. All other half-wave devices
sharing the same AC power source need to follow the same convention. When using a
DC power source, connect its positive terminal to the HI input on the BAS Remote and the
negative terminal to COM on the BAS Remote. Reversing polarity to the BAS Remote
will not damage the BAS Remote.

WARNING: Devices powered from a common AC source could be damaged if a mix of

half-wave and full-wave rectified devices exist. If you are not sure of the type of rectifier
used by another device, do not share the AC source with it.

4.1.2 Limited Power Sources

The BAS Remote should be powered by a limited power source complying with the
requirements of the National Electric Code (NEC) article 725 or other international
codes meeting the same intent of limiting the amount of power of the source. Under
NEC article 725, a Class 2 circuit is that portion of the wiring system between the load
side of a Class 2 power source and the connected equipment. For AC or DC voltages
up to 30 volts, the power rating of a Class 2 power source is limited to 100 VA. The
transformer or power supply complying with the Class 2 rating must carry a
corresponding listing from a regulatory agency such as Underwriters Laboratories (UL).

TD040300-0MF

17

4.2 Connecting Expansion Equipment

Input/output points beyond those available from the BAS Remote Master module can
be increased by adding BAS Remote Expansion modules or by attaching Modbus serial
devices to the MB bus. The MB port is used for connecting to 2-wire Modbus serial
devices while the DN port is used for connecting to BAS Remote Expansion modules.
Both ports are non-isolated EIA-485 compatible.

When installing equipment, make a record that identifies the power source, equipment
locations, IP and MAC ID numbers, protocol in use, baud rate, cable colour coding, etc.
— anything that will be helpful for future staff.

4.2.1 BAS Remote Expansion Module Connections

Expansion modules are intended to occupy positions to the right or left of the Master
module on the same DIN-rail or on additional DIN-rails within the same control panel. In
this situation only a short 2-wire twisted-pair cable is needed for making connections
between DN on the Master module and UP on the first Expansion module. Up to three
Expansion modules can attach to the Master module using a daisy-chain wiring
scheme. The second Expansion module has its UP port connected to the preceding
Expansion module’s DN port. The last Expansion module will have a vacant UP port.
The D+ terminal on one device must attach to the D+ terminal on the other. The same
applies to the D– terminals. Bias and termination exists on the UP terminals. See
Figure 6 for wiring details. For short connections, unshielded cable can be used.
Expansion modules are automatically assigned Modbus addresses beginning with 2
based upon its position to the Master within the daisy-chain wiring.

4.2.1.1 Bias and Termination

Each Master and Expansion module has two Expansion ports. The Master ports are
labelled MB and DN; the Expansion ports are UP and DN. These are shared buses
where only one device drives the bus at any one time. When no device is driving the
bus, the bus floats. To prevent noise from being interpreted as data, the bus must be
biased to a valid state. (The Modbus Serial specification calls this polarization.) With
no data on the bus, the D+ pin is biased to be more positive than the D– pin. Bias is
applied at only one point on the bus: the Master provides bias internally on its MB port,
the Expansion does so on its UP port.

4.2.1.2 Communicating from Master to Expansion Modules

The Master uses the downstream port DN to communicate to the upstream port UP on
the Expansion. If additional Expansion modules are used, they are cascaded such that
the DN port of the Expansion module nearest the Master is connected to the UP port on
the added Expansion module. Commands received by an Expansion module’s UP port
are relayed to its DN port while being read by the module itself. Similarly, a response
received at the DN port is transferred to the UP port — eventually arriving at the Master.
Thus all connections (Master-Expansion and Expansion-Expansion) are point-to-point
with termination and bias in each UP transceiver. DN ports have termination only.

TD040300-0MF

18

4.2.2 Modbus Serial Bus Connections

The Modbus serial Expansion port (MB) on the BAS Remote Master module is non­isolated EIA-485 compatible. When connecting to other non-isolated devices, care
must be exercised to ensure that all non-isolated Modbus devices share the same
ground reference (COM) with the BAS Remote Master module. This is usually
accomplished by sharing the same power source. Configure the Modbus baudrate and
protocol using the BAS Remote Modbus port web page.

Figure 5 — Internal Termination and Bias

When connecting to an isolated 3-wire Modbus device, the signal common of the
isolated device must be connected to the SC pin between the MB and DN ports. This ties
the two reference points together for reliable communications. Refer to Figure 6 for wiring
details.

Modbus serial device can only be attached to the MB port on the Master module. Refer
to Figure 5 for details on the bias and termination network present on the MB port.
Together, these resistors approximate one 120 Ω terminating resistor. Terminal D+
represents the more positive connection for the EIA-485 Modbus serial network while
D– represents the less positive connection. Make corresponding connections to
Modbus serial devices. The last device on the bus should have applied bias and
termination or just termination. A shielded twisted-pair cable should be used with
interconnecting devices. Connect the shields together and attached to chassis at only
one point. Refer to Figure 6 for wiring details.

TD040300-0MF

19

Function

Signalling and
Data Rate

Minimum Required Cable

Maximum Segment Distance

Ethernet

10BASE-T
10 Mbps

Category 3 UTP

100 m (328 ft)

Ethernet

100BASE-TX
100 Mbps

Category 5 UTP

100 m (328 ft)

I/O

Unspecified

Solid: 16–22 AWG
Stranded: 16–18 AWG

Unspecified
Expansion

Unspecified

Belden® 9841 or equivalent*

100 m (328 ft)

Modbus

Varied

Belden® 3106A or equivalent*

100 m (328 ft)

4.2.3 Cabling Considerations

When attaching cables to the BAS Remote, Table 1 should be considered.

Table 1 — Cabling Considerations

* If using shielded cable, connect to chassis at only one point.

NOTE: Wire size may be dictated by electrical codes for the area where the equipment
is being installed. Consult local regulations.

Observe in Table 1 that 10BASE-T segments can successfully use Category 3, 4 or 5
cable — but 100BASE-TX segments must use Category 5 cable. Category 5e cable is
highly recommended as the minimum for new installations.

The Ethernet port of the BAS Remote employs Auto-MDIX technology so that either
straight-through or crossover cables can be used to connect to the network.

TD040300-0MF

20

5 Field Connections

5.1 Sample BAS Remote Wiring Diagram

Figure 6 — Sample BAS Remote Wiring Diagram

Wire Channels 1–6 so the most positive wire goes to

the “A” terminal and the most negative wire to the “B”

terminal.
The wiring options for Channels 1–6 are shown in

Figure 7. For each case in which polarity matters,
proper polarity is indicated.

Considerations in making field connections for various
types of input and output devices are discussed in the
following pages.

Figure 7 — I/O Options (Channels 1–6)

TD040300-0MF

21

5.2 Thermistors

The BAS Remote has built-in calibration curves for 10 kΩ Type II or Type III thermistors.
These devices have a non-linear with a negative coefficient of resistance to temperature
and provide a nominal resistance of 10 kΩ at 25°C. Using the web server, configure an
input for either Type II or Type III thermistor. As shown in Figure 8, connect the two­wire thermistor to points A and B. Polarity is not an issue. If averaging of temperature
is desired, connect multiple thermistors in a series-parallel combination so that the nominal
resistance remains at 10 kΩ as shown. Make sure that all devices are of the same type.
The effective range of temperature measurement is from +40° to +110°F (+4.4° to
+44°C). An open input results in a fault condition that produces a red LED indication for
that channel.

Figure 8 — Thermistor Connections

5.3 Contact Closure

The BAS Remote can sense the make or break of a contact from a relay or push-button.
The contacts being sensed must be absent of any applied source of energy, and be
rated for low-voltage, low-current switching. The BAS Remote will provide the electrical
energy to be sensed. Using the web server, configure an input for contact closure. As
shown in Figure 9, simply connect the contacts between points A and B. For common
mechanical contacts, polarity is not an issue. The open-circuit voltage is 24 VDC and the
short-circuit current is 2 mA.

TD040300-0MF

22

Figure 9 — Contact Closure Connections

For solid-state switches, there are further concerns. It is recommended that a solid­state device have an opto-isolated open-collector NPN transistor output stage with a
collector-emitter output voltage (Vce) of at least 30 V. Output sinking current should be
greater than 5 mA. The collector-emitter saturation voltage should be less than 0.2 V
when sinking 2 mA. The emitter should be connected to point B and the collector to
point A which is the more positive point. This polarity must be observed when using
solid-state devices. When an input is configured for a contact closure, the BAS Remote
sets the low-threshold to 2 V and the high-threshold to 3 V. When a contact is made or
the solid-state switch is on (resulting in a saturated output), the voltage at point A is
close to zero volts. The corresponding LED for that channel will be on. If the contact is
opened or the solid-state switch is turned off, the voltage at point B will quickly begin to
rise towards 24 V. Once the voltage passes the 3 V high-threshold, the input channel
will sense the “off” state. To return to the “on” state, this voltage needs to return to 2 V.
The one-volt difference is called hysteresis. There is no need to add an external pull-up
resistor when using a contact closure input.

Contact closure inputs are sampled every 10 ms and for a change of state to be
recognized, the input state must be stable for two consecutive samples. Therefore,
contact closure response is from 20–30 ms.

TD040300-0MF

23

5.4 Pulse Inputs

A variation on contact closure inputs is pulse inputs. In this situation speed is critical so
the input filtering that limits the time response is removed. When an input is configured
for Pulse Input, a pulse rate up to 40 Hz can be measured, assuming a 50% duty cycle.
The pulse device could have an opto-isolated open-collector NPN transistor output
stage like the one identified under Contact Closure, or it could provide an active
sinusoidal output signal that needs to be detected. Data can be in the form of frequency
or pulse count.

The Pulse Input voltage range is 0–10 VDC and the installer can set both the low­threshold and high-threshold on the Pulse Input web page. The difference in the two
thresholds is the hysteresis. You can detect sinusoidal input signals by setting the high
threshold below the positive peak and the low threshold above the negative peak.
Setting the two thresholds well toward the centre of the sinusoidal waveform (rather than
near its peaks) offers some noise immunity. It is not necessary for the input signal to
swing from zero to 10 V. Any substantial swing within this range can be detected. The
input impedance using Pulse Input is 100 kΩ. Connect the output of the pulse device to
point A and the common to BAS Remote common as shown in Figure 10.

Figure 10 — Pulse Input Connections

The pulse output could be sinusoidal with no DC offset so the BAS Remote could
experience both positive and negative excursions of the signal. The BAS Remote can
only detect positive voltages so the negative excursions will be ignored. It is still
possible to detect the input signal by only sensing the positive excursions.

When interfacing to a pulse device that has an opto-isolated open-collector output, a pull-up
resistor must be added to the device output. In Figure 10, a 3-phase wattmeter has three
opto-isolated open-collector outputs, each requiring an external pull-up resistor. Since

TD040300-0MF

24