Macurco BRS-485 User guide

Macurco™ BRS-485
Multi-protocol RS-485 Adapter

User Instructions

IMPORTANT: Keep these user instructions for reference .

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Table of Contents

1 General Safety Information ...................................................................................................................... 4

1.1 List of warnings................................................................................................................................. 4

2 Use Instructions and Limitations .............................................................................................................. 5

2.1 Use For ............................................................................................................................................. 5

2.2 Do NOT use for ................................................................................................................................. 5

2.3 Features ........................................................................................................................................... 6

2.4 Specifications .................................................................................................................................... 7

3 Installation Instructions............................................................................................................................ 8

3.1 Location ........................................................................................................................................... 8

3.2 Installation ........................................................................................................................................ 8

3.3 Connection .....................................................................................................................................10

3.4 Wiring ............................................................................................................................................11

3.4.1 Signal Wire .......................................................................................................................11

3.4.2 Topology ..........................................................................................................................11

3.4.3 Length ..............................................................................................................................12

3.4.4 Grounding ........................................................................................................................12

3.4.5 Power Wire ......................................................................................................................13

4 Configuration .........................................................................................................................................14

4.1 Macurco NPU Software ..................................................................................................................15

4.2 Addressing and Communication Settings ........................................................................................16

4.3 Firmware and Configuration Update ...............................................................................................18

5 Operations .............................................................................................................................................20

5.1 Power up ........................................................................................................................................20

5.2 4-20mA Loop ..................................................................................................................................20

5.3 Normal Operation ...........................................................................................................................20

6 Troubleshooti ng .....................................................................................................................................21

6.1 On-Board Diagnostics ......................................................................................................................21

6.1.1 Unknown Sensor Code ......................................................................................................21

6.1.2 Error Codes ......................................................................................................................21

6.2 Status LED States ............................................................................................................................22

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7 Maintenance .........................................................................................................................................23

7.1 Cleaning .........................................................................................................................................23

8 Testing...................................................................................................................................................24

8.1 Operation Test ................................................................................................................................24

8.2 Manual Operation Test ...................................................................................................................25

9 Appendix A ............................................................................................................................................26

10 Appendix B – Table of Figures ................................................................................................................30

11 Macurco Gas Detection Product Limited Warranty ................................................................................31

Technical Support Contact Information .................................................................................................................. 32

General Contact Information ................................................................................................................................... 32

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WARNING

Each person usi ng this equipm ent must read and understa nd the information in this user manual before

user manual, may adversely affect product performance.

This equipment may not function effectively below 0°F or above 125°F (-18°C or above 52°C). Using the
detector outside of thi s temperature range may adversely affec t product performance.

Do not disassemble unit or attempt to repair or modify any component of this instrument . This instrument

void product warranty.

1 General Safety Information

The Macurco BRS-485 Adapter is an accessory used to convert the 4-20mA analog signal from Macurco 6-Series
type detectors to a dig ital signal for use with multipoint addres sable systems. The Macurco BRS-485 sim ply
connects to the back of the detector and a single screw fastens it in place. The BRS-485 accepts the 4-20mA
output and is powered from the same connection as the detector. The BRS-485 ca n interface with Building
Automation Systems, Control Panels or other Control Devices that accept Modbus, BACnet, Metasys and
Siemens communi cation protocol.

1.1 List of warnings

use. Use of this equipment by untrained or unqualified persons or use that is not in accordance with this

contains no user service able parts, and substitution of components may impair product performance and

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WARNING

Each person using this equi pment must read and understand the information in this user manual before

user manual, may adversely affect product performance.

2 Use Instructions and Limitations

use. Use of this equipment by untrained or unqualified persons or use that is not in accordance with this

2.1 Use For

The Macurco BRS-485 Adapter converts the Macurco 6-Series 4-20mA analog output to a digital output for use
with addressable net work systems. The Macurco 6-Series is a family of fully programmable, low voltage, dual
relay gas detectors , controllers and transducers for BAS, HVAC an d Fire & Security applications. The 6-Series
detectors are used to measure the concentration of various gases and provide feedback and automatic control
to help ensure a safe e nvironment: Carbon Monoxide, Methane, Propane , Hydrogen, Nitrogen Dioxide and
other gases.

2.2 Do NOT use for

The BRS-485 is not intended for use in hazardous locations or industrial applications such as refineries, chemical
plants, etc. Do not mount the BRS-485 where the normal ambient t emperature is below 0°F or exceeds 125°F (­18°C or above 52°C ). The BRS-485 mounts to a Macurco 6-Series detector installed on a 4” x 4” electrical box
electrical box suppl ied by the contractor.

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2.3 Features

• The Macurco BRS-485 interfaces the detector power and 4-20mA output lines with a mounted connector

• The BRS-485 monitors sensor type, gas level and trouble status communications from any of the

Macurco 6-Series detectors

• Supports Modbus, BACnet, Metasys and Siemens communication protocol .

• Communication is on a serial line with a “Two-Wire” electrical interface in accordance with EIA/TIA-485

standard using RTU Trans mission Mode

• Commercial type enclosure to protect and support the electronics

• Tricolor LED indicates power, test and communica tion status

• Mounts behind the detector inside of a standard 4” x 4” electrical box

• Held in place on the back of the 6-Series detector with a single screw

• USB connection to configure address and communication protocol and settings.

• RS-485 termination uses 3 pin connectors with jumper to select termination: The user selects no

termination or 120 O hm termination.

• Communications connections incl ude signal (A and B), Common and shield terminals

• Intended for use in non-hazardous areas such as parking garages, warehouses, or other commercial

facilities

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2.4 Specifications

• Power & Current (without detector): 1.5W (max) from 12 to 24 VAC or VDC.

• Shipping Weight: 0.25 lb (0.11 kg)

• Size: 3 1/2 x 2 x 1 3/4 in. (8.9 X 5.1 X 4.4 cm)

• Operating Environment: 14°F to 122° F (-10°C to +50°C), 20 to 90% RH non-condensing

• Connections: plugs/terminals

• Color: Blue

• Mounting screw and screwdriver incl uded

• BRS-485 operates as Modbus RTU Slave, BACnet MSTP Server, Metasys N2 Slave or Siemens FLN Slave

• Baud Rate:

Modbus: 2400, 4800, 9600, 19200 (default), 38400, 57600, 115200 bps
BACnet: 9600, 19200, 38400 (default), 57600, 76800, 115200 bps
Metasys N2 Slave: 9600
Siemens FLN Slave: 2400, 4800, 9600, 19200 (default), 38400, 57600, 115200 bps

• Parity:

Modbus: Odd, Even (default) and None
BACnet: No Parity
Metasys: No Parity
Siemens: No Parity

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WARNING

This equipment may not function effectively below 0°F or above 125°F (-18°C or above 52°C). Using the
detector outside of thi s temperature range may adversely affec t product performance.

3 Installation Instructions

The following instructions are intended to serve as a guideline for the use of the Macurco BRS-485 Adapter. It is
not to be considered all-inclusive, nor is it intended to replace the policy and procedure s for each facility. If you
have any doubts about the applicability of the equipment to y our situation, call Technical Support at 844-325-

3050.

3.1 Location

Refer to the user instructions of the specific Macurco 6-Series gas detector to which the BRS-485 will be
connected.

3.2 Installation

The Macurco BRS-485 Adapter converts the Macurco 6-Seri es 4-20mA analog output to a digital output for use
with addressable net work systems. The Macurco 6-Series is a family of fully programmable, low voltage, dual
relay gas detectors , controllers and transducers for BAS, HVAC an d Fire & Security applications. The 6-Series
detectors are used to measure the concentration of various gas and provide feedback and automatic control to
help ensure a safe environme nt: Carbon Monoxide, Methane, Propane, Hy drogen, Nitrogen Dioxide and other
gases.

1. Remove the 4-20mA/Power connector from the M acurco 6-Series gas detector.

2. Plug the BRS-485 adapter into the empty 4-pin socket.

3. Install the provided BRS-485 screw.

4. See the wiring diagram for wire connection.

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5. The 6-Series detector mounts on a 4”x 4” electrical box supplied by the contra ctor.

6. Connect the detector to the control cabl es with terminal plugs. When making connections , make sure

the power is off.

7. There are two terminals for the dry alarm relay contacts, again with no polarity preference. The alarm

relay can switch up to 0.5 A 120 V, o r 60 VA. The alarm relay is activated if gas reaches or exceeds th e
alarm settings. See Ope ration of the detector User Instructions fo r details on relay settings.

8. The alarm relay can be configured to normally open (default) (N.O.) or normally clos ed (N.C.) and will

activate if the gas concentration exceeds alarm set point. It will deactivate once the gas concentration
drops below the alarm set point. Note that the “disable” setting will cause the alarm relay not to engage
at all.

9. The dry contact, SPDT fan relay has three terminals: The Common (COM ), normally open (N.O.) and the

normally closed (N.C.) contact. The fan relay can switch up to 5.0 A up to 240 VAC. See Operation sect ion
of the detector User Inst ructions for details on relay setting s.

Figure 3-1 BRS-485 Installation Expanded

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3.3 Connection

The Macurco BRS-485 output is connected via a four-terminal screw type conne ctor. The BRS-485 adapter is
wired in the standard 2W-Modbus circuit s definition with selectable built-in terminati ng resistors at the ends of
the RS-485 bus. The power for the BRS-485 adapter is connected via a two-terminal screw type connector, 12 to
24 VAC or 12 to 24 VDC and no polarity.

Note: Running the Modb us cable adjacent to or in the same conduit w ith high voltage wires is not
recommended as there may be interference from the high voltages. Line polarization should not be required for
the BRS-485 but may be re quired for other devices on the RS-485 l ine - see manufacturer’s directions.

Figure 3-2 Connection Expanded

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3.4 Wiring

3.4.1 Signal Wire

A serial Line Cable should be shielded for best performanc e. The shield should be connected on each detector at
SHD terminal and connect ed to a ground terminal or chassis onl y at one end of the bus. An RS-485 must us e a
balanced pair (for A & B) and a third wire (for the Common). For RS- 485, Wire Gauge must be chosen sufficiently
wide to permit t he maximum length (1,000m or 3, 281ft). AWG 24 is always sufficient for the Data. Category 5
cables may operate for RS-485, to a maximum l ength of 600 m 1968.5 ft. For the balanced pai rs used in an RS­485-system, wire wit h a characteristic impedance of higher than 10 0 Ohms may be preferred, especially for
19200 and higher baud rates.

Note: It is recommended to always use twisted wires to reduce noise and allow for reliable data communication
over greater distances. Use at le ast 3-conductor wire with one twisted pair providing a pair for signal (A & B) and
Common (COM) connec tions.

For best performance use shielded 3-conductor wire with one twisted pair providing a pair for signal (A & B),
Common (COM) and shie ld ground (SHD) connections.

3.4.2 Topology

An RS-485 configuration wi thout repeater has one trunk cable, along which devices are connected, directly
(daisy chaining) or by short derivation cables. The trunk cable, also named “Bus”, can be long. Its two ends must
be connected on Line Termi nations. (see Line Termination - End of Line Resistor section). The use of repeaters
between several RS-485 is also possi ble.

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3.4.3 Length

The end to end length of the trunk cable must be limited. The maximum length depends on the baud rate, the
cable (Gauge, Capa citance or Characteristic Impedance), the number of loads on the daisy chain, and the
network configuration (2-wi re). For a maximum 9600 Baud Rate and AWG26 (or wider) ga uge, the maximum
length is 1000m 3281ft. The derivations must be short, never more than 20m 65.5ft. If a multi-port tap is used
with n derivations , each one must respect a maximum length of 4 0m 131ft divided by n.

3.4.4 Grounding

The Common circuit (COM) must be connected directly to protective ground, preferably at one point only for
the entire bus.

Figure 3-3 Modbus Wiring

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Wire gauge

Feet

Meters

18

500

152

16

800

244

14

1250

381

3.4.5 Power Wire

All field wiring is completed via modular connectors (provided). After wiring, simply plug the modular
connectors into the matc hing connectors on the BRS-485. The powe r connections to the remote mo unted
detectors should be siz e AWG18 (minimum) for short runs. Since Ma curco detectors are rated for operation
between 12 and 24 VDC or VAC, the vol tage drop between the power supply and the BRS-485 shoul d not be an
issue if the recommended power wire gauge guidelines below are followed. The terminals will accept wire from
16 to 28 AWG. To ins tall a wire, strip back approx imately 0.25 in. (6 mm) of ins ulation and insert the bare wi re
into the terminal. Tighten the screw clamp and ensure that the wire cannot be easily pulled from the connector.

Table 3-1 Power Wire lengths

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4 Configuration

Figure 4-1 NPU Program

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4.1 Macurco NPU Software

Macurco Network Parameter Utility software can be used to set the BRS-485 to desired address, change the
communication protocol and communication settings. This software can also be used to update BRS-485 with
any latest firmwa re release from Macurco. Figure 4.1 shows the s creen of NPU software when a device is
connected. As shown in the Figure, it displays the device name (BRS-485) with device configuration versi on
(V1.0DS) under it. Fields greyed out are read-only.

Protocol- Factory default for this field is BACnet. Click on drop down list to select appropriate communication
protocol. Modbus, BACne t, Metasys and Siemens are protocol supported by BRS-485.

Address - The address of the device in the network. This setting is not available for BACnet.

MAC Address: Defines the address (0-127) that the BRS-485 (node) will reside on the network. This setting is
available for BACnet only .

Baud Rate - Baud rate of the network.

Parity - Parity for the communication.

Response Delay: Time in milliseconds that the drive r waits before responding to master requests. If no delay is
required, setting t his field to 0 instructs the driver to send it s response as soon as possible. This setting is not
available for BACnet.

APDU Timeout - The time in milliseconds that the driver will wait for a response from a device after sending a
request. This setti ng is available for BACnet only.

A number of APDU Retries - The number of times the driver will retry a request when a response is not received.
This setting is ava ilable for BACnet only.

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Device Name: Device name that will appear for BRS-485 in BACnet network. The device name must be unique
across the enti re BACnet network. Enter a string of between 1 and 16 characters long. This setting is available
for BACnet only.

Device Instance: Object Instance for BRS-485 device BACnet object. The instance number must be unique across
the entire BACnet network. Valid entries are between 0-4194302. This setti ng is available for BACnet only.

Max Master: Defines the highest allowable address (0-127) for M S/TP master nodes on the network. Any
address higher than this will not receive the token from the unit. Note that this value must be greater than or
equal to the configured M AC Address(es). If the highest address on the network is unknown, set this fiel d to

127. This setti ng is available for BACnet only.

4.2 Addressing and Communication Settings

Connect BRS-485 to PC usi ng mini USB to USB adapter, and open Macu rco NPU software. Macurco NPU
software will displ ay the current settings of the BRS-485. Update t he settings in Macurco NPU software and hit
Submit to load the updated settings into BRS-485. Footer of the NPU software displays the status of the settings
update.

Figure 4-2

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Communication Protocol

Valid Address

Modbus RTU

1…247

BACnet MS/TP

0…127

Metasys N2

1…255

Siemens FLN

1…98

NOTE: After any configuration change, disconnect the USB cable from BRS-485 and perform power res et for
BRS-485.

Following table shows the valid addresses for different protocols.

Table 4-1

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4.3 Firmware and Configuration Update

To receive the latest version of Macurco NPU, as well as fi rmware and configurations, download the Ma curco
NPU from our website http://www.macurco.com/downloads.htm l. If a newer version of firmware is available in
the NPU you will be prom pted to update when connected to the BRS-4 85.

Macurco NPU Folder downloaded from website contains a file "BRS-485_VXXX.DUF " where VXX is the version
number. This file is the configuration file for different communica tion protocol supported by BRS-485. This
configuration file can be uploaded to BRS-485 using following procedure.

a. Open the Macurco Network Parameter Utility Software.

b. If BRS-485 is connected to PC via USB, the software will display home screen like one in Figure 5-1. If Software
does not detect the BRS-485 it will display “No Device Connected”. Make sure software detects the panel before
proceeding.

c. Go to File (on the top left corner of the software) and select “Update Device…”.

d. A new window will pop up to select the file. Select the DUF file and hit Open.

e. Now the DUF file will be loade d into the panel. The progress of the file update is displ ayed at the bottom.

f. Once the update is complete it will reset the device and it will return to home s creen. Verify the correct
version of the device con figuration file is updated. Device confi guration version is displayed alongside the
product image displayed in NPU software. It has format "Multi-Protocol VX.XX" where X.XX corresponds to the
device configuration v ersion.

Figure 4-3

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Place the EOL jumper on one of the following positions:

If Line Termination requirements are different than those provided, then the line termination will need to be
provided by the instal ler.

Y = 120 ohm
N = No termination (default)

Figure 4-4 BRS-485 Front view

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5 Operations

5.1 Power up

The Macurco 6-Series detector cycles through an internal sel f-test cycle for the first minute that it is powered.
The unit will execute the test cycle any time power is dropped and reappl ied (i.e. power failure). During the self­test cycle the unit will displa y the firmware versi on number, then count d own from 60 to 0 (if the di splay setting
is “On”) and finally go into normal operation. The alarm relay will be activated for 10 seconds and the fan rel ay
for 60 seconds during t he power-up cycle unless the “Power Up Test ” (PUt) option is OFF. The indicator li ght
(LED) will flash green during the self-test cycle. At the end of the 1-minute cycle, the unit will take its first sample
of the air and the indica tor light will turn solid green.

The BRS-485 is an adapt er which allows the reading of a 6-Series gas detector over a RS-485 inte rface. To
achieve this, the BRS-485 will monitor the 4-20 mA current output of the detector. At power up and during its
warm-up period, the 6 -Series detector will communicate its sensor type over the 4-20 current output us ing a
custom protocol. Th e BRS-485 will automatically register each 6-Series detector as it is programmed with
information about all the detectors to which it can be connected. The BRS-485 will use this information t o
determine the gas level sensed by the 6-Series detector by measuring the 4-20 mA current-loop output during
normal operation of the detector.

5.2 4-20mA Loop

The 4-20mA Loop must be enabled “ON”, the 6-Series detector. If the 4-20mA loop has been disabled “OFF” the
6-series detector wil l not be able to send the signal informati on to the BRS-485.

5.3 Normal Operation

When the LED is solid GREEN, operation is normal, the BRS-485 knows the detector type, no errors ar e detected,
and no data are being received or tra nsmitted over the RS-485 line.

When the LED is GREEN with random burs ts of AMBER, operation is normal and now data are being received or
transmitted over the RS-485 line. The AMBER LED will come on any time that there is data traffic.

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6 Troubleshooting

6.1 On-Board Diagnostics

6.1.1 Unknown Sensor Code

GREEN/OFF Alternating every 500 milliseconds - The BRS-485 does not know the detector type, no Modbus
communications are in p rogress and no errors are detected.

To correct this conditi on:

1. Disconnect the power line from the BRS-485.

2. Disconnect the communication line from the BRS-485.

3. Re-connect the communication line to the BRS-485.

4. Re-connect the power line to the BRS-485.

6.1.2 Error Codes

Solid RED - The BRS-485 detected an error and no Modbus communications are in progress.

RED with random bursts of AMBER - The BRS-485 detected an error and AMBER is displayed when data are

received or transmitted over the RS-485 line

There are a number of conditions whi ch are signaliz ed in this way:

• Current EEPROM Settings not initialized

• Current EEPROM Settings have bad checksum

• Factory EEPROM Settings not initialized

• Factory EEPROM Settings have bad checksum

• Unknown Sensor exponent value

• Watchdog reset

• Loaded Factory EEPROM Settings in EEPROM Current Settings

• Latched sensor type different than registered sensor type

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LED State

Description

Operation is normal, the BRS-485 knows the detector type, no errors are detected, and
Solid Green with Burst s of Amber

Operation is normal and data is being received or transmitted over the RS-485 line.

The BRS-485 doesn’t know the detector type, no errors are detected, and no data is

Green/Red Alternating every

The BRS-485 detected an error (BRS-485 Status is non-zero) and no RS-485

The BRS-485 detected an error (BRS-485 Status is non-zero) and Amber is displayed

A fatal error has occurred. The number of flashes indic ates the error code, followed by 2

• Unknown sensor type because registration failed

6.2 Status LED States

Solid Green

Green/Off Alternating every 500ms

200ms

Solid Red

Red with Bursts of Amber

Flashing Red

no data is being received or transmitted over the RS-485 line.

being received or transmitted over the RS-485 line.

Operation is normal and a USB connection has been made to a PC.

communications are in progress.

when data is received or transmitted over the RS-485 line.

seconds of off time.
1 – 5 = For internal use: contact Macurco for assistance

6 = USB to Serial Pass-Throug h mode

7 = Invalid or corrupt configuration. Use NPU to modify settings, recover configuration,
or download a DUF file.

8 – 10 = For internal use: contact Macurco for assistance

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WARNING

Do not disassemble unit or attempt to repair or modify any component of this instrument . This instrument

void product warranty.

7 Maintenance

The BRS-485 does not require regular maint enance. All maintenance and repair of products manufa ctured by
Macurco are to be performed at the a ppropriate Macurco manufacturing facility. Macurco does not sanction
any third-party repair facilities.

contains no user service able parts, and substitution of components may impair product performance and

CAUTION

Avoid the use of harsh cleaning materials, abrasives, and other organic solvents. Such materials may
permanently scratch the s urfaces and damage the LEDs, labels, or instrument housing.

7.1 Cleaning

Cleaning of the ext ernal surfaces is best carried out using a dam p cloth with a mild detergent or soap. Us e a
vacuum cleaner with soft brush to remove dust or contamination. Do not blow out the sensor with compressed
air.

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8 Testing

The Macurco BRS-485 adapter co nverts the 4-20mA analog signal from Macurco 6-Series type detectors to a
digital signal for use with multipoint addressa ble systems. The 6-Series test procedures may be used to ensure
that the BRS-485 accepts the 4-20mA output for communicati ons. All 6-Series detectors are factory calibrated
and 100% tested for prope r operation. The units also perform a reg ular automatic self-test during normal
operation. If the unit detects an imprope r voltage or inoperable component, it w ill default into Error mode. In
this error mode, the Fan and Alarm relays will be activated, the 4-20 mA out put will go to 24 mA, the unit will
display the error code and the buzzer will chirp intermitte ntly.

8.1 Operation Test

Normally this will be the only test required for the 6-Series detectors and is the recommended way to test the
unit or units after installation. Check that the detector operating LED light is illuminated Green continuously. If
not, do not proceed wit h the tests. If the unit is in error mode, c ontact your local representative or Ma curco
technical service representative for information on resolving the problem.

1. Remove the single screw in the middle of the front cover of the 6-Series detector.

2. Remove the front cover.

3. Observe the LED light on the front of the 6-Series detectors.

4. If the light is solid green, proceed to step 6.

5. If the light is off or flashing Green, refer to the Section 5.3 Normal Operation above.

6. Locate the switch labeled ENTER/TEST on the left side of the printed circuit board. Press the Test switch

once.

7. The 6-Series detector will step through a cycle test:

a. The display progresses through the bUZ (buzzer Test) Art (alarm relay test), Frt (fan relay test)

then 42t (4-20 mA output test).
b. Make sure that the settings are “on” and not disabled “diS”.
c. During the first 10 seconds of the test cycle, the display will show “bUZ” and set off the audible

buzzer.
d. The alarm relay will be clo sed, so any devices connect ed to that relay will be tested.

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e. The Fan relay will be activated for the next 1 minute of the test, so if the fan circuits are wired in

the typical manner, t he fan should run.
f. The 4-20mA output will the n ramp up from 4 to 16 mA over the next 130 seconds of the test, so if

the circuit is wired in the normal manner, the con trol panel or building automation system should

respond.
g. At the end of the test cycle, the light will turn green and be on steady (Normal Operation), the fan

and alarm relays wi ll be in standby mode and the 4-20 mA output w ill return to 4 mA in clean air

8. When testing is completed, reassemble the unit or units

8.2 Manual Operation Test

This option gives the user the opportunity to manually i nitiate an indiv idual test for the audible buzzer, each
relay, the analog output and the sensor response to gas. From normal operation mode, press the Nex t button 2
times to get to the Test Mode (tSt). Press the Enter button once to get into the Test Menu. Press the Next
button to scroll through the Four test options and press Enter to initiate the selected test. Note that if the relay
or 4–20 mA output has been disabled, the test selection wi ll not be displayed in the test menu.

(Exception for Oxygen w ith OX-6).

bUZ – Buzzer Test, 4 seconds
Art – Alarm Relay Test, 6 seconds
Frt – Fan Relay Test, 60 seconds
42t – 420 Loop Test, 135 seconds
gSt – gas test, xxx seconds (available on select detectors)

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Detector

Sensor
Type

Sensor Range

Sensor
Resolution

CM-6 1 200ppm

1ppm

TX-6-ND

2

20.0ppm

0.1ppm

GD-6 3 50% LEL

1% LEL

TX-6-AM

4

100ppm

1ppm

TX-6-HS 5 50ppm

1ppm

RD-6 6 1000ppm

10ppm

OX-6 8 25.0% v/v

0.1% v/v

CD-6H 9 5000ppm

50ppm

CD-6MC

9

5000ppm

50ppm

CD-6G

10

5.00% v/v

0.01% v/v

CX-6

1 (CO)

200ppm (CO)

20.0ppm (NO2)

1ppm (CO)

0.1ppm (NO2)

9 Appendix A

Please refer to BRS-485 product page in www.macurco.com for details on Modbus Registers, BACnet Objects,
Metasys N2 Objects, a nd Siemens FLN points.

NOTE: BRS-485 dynami cally adjusts which objects/registers are exposed on the network based on whether a
single-sensor detector or dual-sensor detector is detected by the BRS-485. So, please refer to corresponding
object mapping available on the BRS-485 product page in www.macurco.com. For dual sensor (CX-6), S1 refers
to carbon monoxide sens or and S2 refers to nitrogen dioxide s ensor.

BRS-485's network drive r does not start up until a valid Macurco de tector is recognized and hence
objects/registers are not exposed until after successful registrati on with valid Macurco detector. Following table
list valid detector ty pe for BRS-485 along with other detector details.

2 (NO2)

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Cal Due Days

Description

Information related to detector/sensor such as sensor reading, sensor type, sensor resolution, and sensor range
are accessible via M odbus, BACnet, Metasys and Siemens communicat ion protocol.

NOTE: Value of Sensor readi ng object/register is not reliabl e when trouble object is set or sensor type is
anything other than listed in table above. In such case other objects such as Sensor Type, No Signal, Calibration
Overdue, Trouble, Wa rm Up etc. must be monitored to validate sensor reading and g et current state of the
detector.

NOTE: Due to limitat ion of Siemen FLN protocol, readings for CD-6H an d CD-6MC might not be communicated
correctly if FLN master interprets 16-bit values as signed integers. So, BRS-485 for use with CD-6H and CD-6MC is
not recommended for Si emen FLN protocol if FLN master interprets 16-bit values as signed integer.

NOTE: Due to limitation of Siemens FLN protocol and variation in range and resolution of Macurco detectors,
BRS-485 when used with CD-6G for Siemens FLN protocol will round readings for CD-6G to one decimal place
instead of two decimal place readings displayed on CD-6G detector. Due to same reason, resolution for CD-6G
will be displayed as 0.0 instead of 0.01.

In addition to this, BRS-485 also provides following additional informati on about BRS-485 and detector
connected to BRS-485.

a. Last Sensor Type

It is the last sensor id detected by BRS-485 at last power on.

b. Cal Due Days

It represents the number of days until the detector connected indicates calibration overdue. Refer to product
manual to verify if t he detector used supports calibration period o r not. Following table represents some
possible values for thi s field.

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65535

Calibration Due feature is disabled.

65534

Unknown value (not transmitted by detector yet)

65533

Calibration Period feature not supported by detector

31

There are more than 30 days until calibration due

1 - 30

Indicates number of days left before calibration overdue

0

Calibration Overdue

Cal Due Days

Description

255

Calibration Due feature is disabled.

254

Unknown value (not transmitted by detector yet)

253

Calibration Period feature not supported by detector

241

There are more than 30 days until calibration due

1 - 240

Indicates number of days left before calibration overdue

0

Calibration Overdue

b. UntilCalDue

Like Cal Due Days it is also consists of information related to time left until the detector connected indicates
calibration overdue. But, value represented is the intervals of 3 hou rs until calibration overdue.

c. No Signal

When there is no signal on the 4-20mA output of the detector connected to BRS-485, the corresponding bit of
Modbus register or cor responding object i s set.

d. Cal Overdue

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When the detector connected goes int o calibration overdue, then the corresponding bi t of Modbus register or
corresponding object is set. Pleas e refer to product manual to check if detector supports this feature and refer
to the manual for detai l on Calibration Overdue.

e. BRS485 Status

When the BRS-485 status is not zero, then it will set this object. Following are possible reasons for non-zero BRS­485 status.

- When calibration data cannot be loaded. This is related to factory operation and should not occ ur in the field.

- When incompatible/unknown detector is connected to BRS-485.

f. Warm up

This is set during the first 60 seconds after power is applied to BRS-485. Since objects are not exposed until
successful registrat ion by BRS-485, this object might not appear for t he first 30 seconds of power up.

g. Over Range

This is set when there is over range signal on the current loop.

h. Trouble

This is set when there is trouble signal (24mA) on the current loop. This is also set when No Signal or Calibration
overdue is set.

i. Cal Error

This is set when the calibration data cannot be loaded and BRS-485 is not calibrated. This is related to factory
operation and should be 0 when used in the field. Do not use BRS -485 if this object is set.

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j. Unknown Sensor

This is set when BRS-485 is connected to unknown/incompatible detector.

10 Appendix B – Table of Figures

Figure 3-1 BRS-485 Installation Expanded .............................................................................................................. 9

Figure 3-2 Connection Expanded ..........................................................................................................................10

Figure 3-3 Modbus Wiring....................................................................................................................................12

Table 3-1 Power Wire lengths ..............................................................................................................................13

Figure 4-1 NPU Program ......................................................................................................................................14

Figure 4-2 ............................................................................................................................................................16

Table 4-1 .............................................................................................................................................................17

Figure 4-3 ............................................................................................................................................................18

Figure 4-4 BRS-485 Front view .............................................................................................................................19

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11 Macurco Gas Detection Product Limited Warranty

Macurco warrants the BRS-485 Adapter wil l be free from defective mat erials and workmanship for a peri od of
two (2) years from date of manufacture (i ndicated on the c over of the BRS-485 ), provided it is maintained and
used in accordance wit h Macurco instructions a nd/or recommendations . If any component bec omes defective
during the warranty period, it will be replaced or repaired free of charge, if the unit is returned in accordance with
the instructions be low. This warranty does not apply to unit s that have been altered or had repair attempted, or
that have been subje cted to abuse, a ccidental or otherw ise. The above warranty is in lieu of all other express
warranties, obligations or liabilities. THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
PARTICULAR PURPOSE ARE LIMITED TO A PERIOD OF TWO (2) YEARS FROM THE PURCHASE DATE. Macurco shal l
not be liable for any i ncidental or cons equential damages for breach of this or a ny other warranty , express or
implied, arising out of or related to the use of said gas detector. Manufacturer or its agent’s liability shall be limited
to replacement or repair as set forth above. Buyer’s sole and exclusive remedies are return of the goods and
repayment of the price, or repair and replacement of non-conformi ng goods or parts.

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Macurco Inc.

1504 W 51st St.
Sioux Falls, SD 57105

Technical Support Contact Information

Phone: [phone]
Fax: [phone]
Email: support@macurco. com
Website: www.macurco.com/support/

Rev – 1.0.1
Issue Date: 2.20.2023
Document No: 34-2900-0019-7

© Macurco 2023. All rights reserved.

General Contact Information

Phone : [phone]
Fax : [phone]
Email : info@macurco. com
Website: www.macurco.com