Dwyer Series GSTC Specifications-Installation And Operating Instructions

Dwyer Series GSTC Carbon Monoxide/Nitrogen Dioxide Gas Transmitter monitors gas concentration in underground parking garages and loading docks. Compatible with BACnet or Modbus® communication protocol, it can be used with almost any building management controller. Field-replaceable electrochemical sensors have a 2-year lifespan and provide accurate readings (CO: 2% FS; NO2: 3% FS) for up to 5000-7500 sq ft.

PDF

Document

Wall mount with LCD

Bulletin AQ-GSTC

Series GSTC Carbon Monoxide/Nitrogen Dioxide Gas Transmitter

Specifications - Installation and Operating Instructions

3-45/64

[94.06]

3-1/8

[107.95]

2-15/64

[56.75]

3-23/64

[85]

2-55/64

[73]

2-15/64

[57]

4-17/32

[115.09]

5-7/64

[129.78]

Wall mount without LCD

Duct mount

Wall mount

3-59/64

[100]

Duct mount

The Series GSTC Carbon Monoxide/Nitrogen Dioxide Gas Transmitter monitors the gas concentration in underground parking garages and loading docks. The carbon monoxide transmitter is used to measure the exhaust of gasoline engines, while the nitrogen dioxide transmitter is used for diesel engines. The Series GSTC is compatible with either BACnet or Modbus ® communication protocol, allowing the transmitter to be used with almost any building management controller. The GSTC output is communicated over an RS-485 wire via BACnet or Modbus ® communication protocol.

To maximize the accuracy of the Series GSTC, the sensor can be field-calibrated using the A-449 remote LCD display. When the sensor reaches the end of its life, the display will indicate that the sensor needs to be replaced.

BACnet and Modbus ® communication protocol recommend limiting the number of nodes in any segment to 32. Therefore, the transceiver may be rated at one unit load.

Fractional loads are also acceptable. The Series GSTC accounts as an eighth of a load on the MSTP network.

WARNING Disconnect power supply before installation to prevent electrical shock and equipment damage. Make sure all connections are in accordance with the job wiring diagram and in accordance with national and local electrical codes. Use copper conductors only.

NOTICE

Use electrostatic discharge precautions (e.g., use of wrist straps) during installation and wiring to prevent equipment damage.

Avoid locations where severe shock or vibration, excessive moisture, or corrosive fumes are present.

NOTICE Do not exceed ratings of this device, permanent damage not covered by warranty may result.

NOTICE The electrochemical sensors should be stored in an environment with a minimum humidity level of 20% RH. If the sensor dries out, replacements will not be covered under warranty, but they can be revived by allowing them to stabilize in an environment above 40% RH for 10 days. Once revived, they need to be recalibrated before use.

INSTALLATION

NOTICE These are general guidelines. Local laws or ordinances will take precedence.

• The transmitter should be mounted at normal breathing height, approximately 5 to 6

ft above the floor.

• The unit may be mounted in the horizontal or vertical position. It should be mounted

in an area that is shielded from direct contact with the elements or direct sunlight.

• Mount in an area that will prevent the sensor from having any direct contact with

water.

• The unit should be placed in an area that will give an average of the air quality. Do

not place the unit so it will receive direct engine exhaust. Prolonged exposure to

direct engine exhaust may damage the sensor.

SPECIFICATIONS

Sensor: Field replaceable electrochemical, 2 years typical lifespan.

Range: CO: 0 to 500 PPM, NO

: 10 PPM.

Output Drift: <5% per year in air.

Coverage Area: 5000 to 7500 sq ft typical.

Accuracy: CO: 2% FS, NO

: 3% FS, at the time of calibration.

Resolution: CO: 1 PPM; NO

: 0.1 PPM.

Temperature Limits: -4 to 122°F (-20 to 50°C).

Storage Temperature: For best sensor life, 32 to 68°F (0 to 20°C).

Humidity Limits: 15 to 90% RH constant; 0 to 99% RH intermittent.

Response Time: <45 s to 90% CO, <25 s to 90% NO

Span and Zero Adjustment: Via onboard push-buttons or using optional A-449 display. Zero only via BACnet or Modbus ® communication protocol.

Housing: UV resistant glass filled polycarbonate.

ASCII (switch Output Signals: BACnet MS/TP, Modbus ® RTU, or Modbus ® selectable) communication protocol.

Power Requirements: 10-36 VDC or isolated 21.6-33 VAC, 5.7 mA @ 24 VDC.

Electrical Connection: Removable terminal block, knockouts for conduit fitting.

Calibration: Via onboard push-buttons (LCD model only) or using optional A-449 display. Span gas concentration is field selectable.

Enclosure Rating: IP64.

Weight: 1 lb (0.45 kg).

Compliance: CE.

Figure 1 shows the location of the wiring terminal, 8 position DIP Switch SW1, used for configuring the RS-485 address, the 4 position DIP Switch SW2, used for configuring hardware and software options, sensor, span and zero adjustments, and status LEDs.

The device provides three LEDs to indicate status and activity. The LEDs are located to the right of DIP Switch SW1. The yellow LED indicates that the unit is sending a BACnet or Modbus ® communication protocol. The green LED indicates the unit is receiving a

BACnet or Modbus ® communication protocol addressed to this specific device. The red LED will flash once periodically if the BACnet or Modbus configuration is in progress.

® communication protocol address is set incorrectly or the red LED will flash twice periodically if the auto serial

Span

Sensor

DIP switch

SW2

Wiring terminal

Zero

DIP switch

SW1

Status

LEDs

Figure 1

DWYER INSTRUMENTS, INC.

P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A.

Phone: 219-879-8000

Fax: 219-872-9057 www.dwyer-inst.com

e-mail: [email protected]

Wall Mounting

1. Remove the cover plugs from the face of the unit and the top cover.

2. Disconnect the display cable from the USB connector on the main circuit board (if

present).

3. Remove the desired conduit fitting knock out and install conduit fitting (not

provided).

4. Position the transmitter where it is to be mounted and mark the mounting holes in

each corner of the housing.

5. Drill or punch out marked locations.

6. Place the transmitter box over mounting holes on wall and align. Install wall mount

screws (not provided) in mounting holes.

7. Proceed with wiring diagrams according to Figures 3 and 4.

8. Set DIP Switches SW1 and SW2 as desired. Refer to Figure 5, Figure 6, and

Appendix I.

9. Reconnect the LCD cable to the USB port on the main circuit board (if present).

10. Replace cover and cover plugs on the face of the unit.

CO:

Locate GSTC carbon monoxide transmitter about 5 ft (1.5 m) off the floor. Carbon monoxide weighs about the same as air and distributes evenly throughout the monitored space. Install GSTC CO alarm at least 15 to 20 ft (4.6 to 6.1 m) away from boiler or fuel burning heat source. Avoid extremely dusty, dirty, humid or greasy areas.

Do not place in direct sunlight or areas subjected to extreme temperature. Do not place in turbulent air, near fans, heat vents, air conditioners, air returns or open windows.

Blowing air may prevent CO from reaching the CO sensor.

Figure 3 shows how to connect the GSTC in a network containing a common power supply. Use a cable containing two twisted pairs. One pair is to be used for the power and common. The other pair is to be used for A[-] and B[+]. Attach the shields together with a wire nut. This configuration is not suitable for AC supplies. Use a DC supply only. Care should be taken that there are not too many devices powered from the same supply as voltage drops will occur in the wiring. If you have many devices, or have long cable runs, the local supply configuration, shown in Figure 4, may be a better choice.

COM PWR A[-] B[+]

1 2 3 4

TO PREVIOUS

DEVICE

B[+]

A[-]

PWR

COM

ATTACH SHIELDS

TOGETHER W/WIRE NUT

TO NEXT

DEVICE

B[+]

A[-]

PWR

COM

sensors should be mounted in the breathing zone, 4 to 6 ft (1.2 to 1.8 m) from the floor. This is primarily because NO

is a poisonous gas which should be detected in the area where people would be exposed to it, but also because 4 to 6 ft from the floor is an appropriate elevation to detect NO

gas.

Duct Mounting

Duct mounting kit includes an air flow pitot tube, air filter with barbed connections, two short pieces of tubing, and one long piece of tubing.

1. Mount the pitot tube into the duct observing the flow direction marked on the pitot

tube.

2. Attach the two short pieces of tubing to the barbed connections on each side of the

air filter. See Figure 2.

3. Attach the remaining side of one of the short pieces of tubing to the barbed

connection on the transmitter.

4. Attach the remaining side of the other short piece of tubing to the high port on the

pitot tube.

5. Attach the long piece of tubing to the open barbed connection on the transmitter.

6. Attach the other end of the long tubing to the low port on the pitot tube.

TO PREVIOUS

DEVICE

B[+]

A[-]

COM

Figure 3 - Common Power Supply

Figure 4 shows how to connect the GSTC in a network containing individual local supplies. Use a cable containing a single conductor and a twisted pair. The single conductor is to be used for common, and the pair is to be used for A[-] and B[+]. Attach the shields together with a wire nut. Both AC and DC supplies are suitable for this configuration.

COM PWR A[-] B[+]

1 2 3 4

TO NEXT

DEVICE

B[+]

A[-]

COM

ATTACH SHIELDS

TOGETHER W/WIRE NUT

Figure 4 - Local Power Supply

All devices in the network should be daisy-chained. Star connections and T connections are not permitted.

The A[-] and B[+] lines must be terminated at both ends with a 120 Ω resistor. If the

GSTC is an end device it has an on-board resistor that may be used. See Table 1 to enable it.

Figure 2

WIRING

NOTICE Wiring should comply with Electrical Characteristics of Generators and Receivers for Use in Balanced Digital Multipoint Systems,

TIA-EIA-485-A-1998, Telecommunications Industry Association, 1998.

NOTICE BACnet installations should comply with ANSI/ASHRAE Standard

135-2010 BACnet A Data Communication Protocol for Building

Automation and Control Networks, American Society of Heating, Refrigerating and

Air-Conditioning Engineers, Inc., 2010.

The network must be biased properly. If needed, there are bias resistors on-board the

GSTC. No more than two sets of bias resistors should be enabled in the network. See

Table 1 to enable them.

NOTICE Modbus

Modbus

communication protocol installations should comply with

communication protocol over Serial Line Specification and Implementation Guide V1.02, Modbus ® Organization, Inc., 2006.

NOTICE

Communication wiring must be in a daisy-chain fashion. Star connections are not permitted.

Cable shield must be connected to earth ground at one location only.

Dip Switch Configurations

Use DIP Switch SW1 (see Figure 5) to configure the RS-485 address of the device. A valid address depends on the protocol selected. Valid BACnet addresses range from

1 to 127. Valid Modbus ® communication protocol addresses range from 1 to 247. By default, the device is shipped with Modbus ® communication protocol selected and the address set to 127, as shown in Figure 5. A valid and unused address should be set before connecting to an existing network. See Appendix I to configure the required address using DIP Switch SW1. The device will not function properly if an invalid address is set. During the power up sequence, the LCD (if present) will display the

RS-485 address as the primary value and either “BAC” to indicate BACnet or “MOD” to indicate Modbus ® communication protocol as the primary text. If the RS-485 address is invalid, the invalid address is shown as the primary value with “ERR” as the primary text, and the red LED will periodically blink once.

1 2 3 4 5 6 7 8

The auto serial configuration process is completed once a message addressed to the device is received and processed successfully. If the serial configuration of the bus changes, a power cycle of the device is required to restart the auto serial configuration process.

More detailed information for BACnet protocol can be found in Appendix II, and information for Modbus ® communication protocol can be found in Appendix III.

MENU

The menu is only shown if a display is present. Figure 7 below outlines the display components. To enter the menu, press and hold both the SPAN and ZERO pushbuttons for at least 3 seconds. The menu descriptions and list of the available values for each standard menu item is shown on in Table 3. Table 4 lists the available values for each manual menu item.

Figure 5

To activate auto serial configuration, set a valid RS-485 address using DIP Switch

SW1, connect the serial bus, common and power wires, and apply power. The device will power up and begin examining the serial bus for communication.

When the device is installed offline or away from the main network, it is necessary to generate the appropriate traffic in order to configure the serial communication whether

BACnet or Modbus ® communication protocol is selected. While the serial configuration is in progress, the device may not respond. The device may require multiple read requests to complete the serial configuration process.

Use DIP Switch SW2 (see Figure 6) to configure other hardware and software options.

Table 1 shows available options. Table 2 shows supported configurations for either

BACnet or Modbus ® communication protocol.

NETWORK BIAS

Text

Secondary display

Text

Primary display

Figure 7

1 2 3 4

Numeric

PROTOCOL NETWORK TERMINATION

Figure 6

DIP SWITCH SW2 FUNCTIONS

Switch

1 - Protocol

2 - B[+] Bias Resister

3 - A[-] Bias Resister

4 - Terminating Resister

Modbus ®

511Ω Pull-up to 5 V

511Ω Pull-down to GND

120Ω between A[-] and B[+]

Off

BACnet

Pull-up not connected

Pull-down not connected

Open

Table 1

Auto Serial Configuration

Use the auto serial configuration to enable the device to determine the baud rate, parity, and stop bits directly from the serial traffic. After a valid RS-485 address is chosen, the GSTC can be quickly and easily deployed. The auto serial configuration procedure assumes a serial configuration appropriate to the chosen protocol, shown in Table 2. Otherwise, the serial communication must be configured manually in the setup menu.

SUPPORTED CONFIGURATIONS

Protocol Supported Baud Rates Data Size

BACnet

Modbus ®

9600

19200

38400

57600

76800

115200

Table 2

Parity

None

Even

Odd

None

Stop Bits

Standard Menu Descriptions

BAC or MOD: Displays the RS-485 address

CAL:

calibration process

AUT: Auto serial configuration enabled

RST: Reset settings to factory default

Manual Menu Descriptions

BAU: Baud rate selection (only available if AUT = OFF)

Parity selection (only available if AUT = OFF)

STP: Stop bits selection (only available if AUT = OFF)

Menu Navigation

A menu flowchart, located in Appendix IV, illustrates the navigation process.

1. Press and hold the SPAN pushbutton while in the menu to move to the previous

menu item.

2. Press and hold the ZERO pushbutton while in the menu to move to the next menu

item.

3. Press and hold both the SPAN and ZERO pushbuttons for 5 seconds to activate

the current menu item. In the lower left corner of the display “SET” is shown to

indicate a setting change.

4. Press and hold either the SPAN or ZERO pushbutton to change the setting.

5. Press and hold both the SPAN and ZERO pushbuttons for 5 seconds to accept the

setting.

6. After 30 seconds of inactivity, the display will return to normal operation.

STANDARD MENU OPTIONS

Menu Name Value

BAC or MOD xxx ADR RS-485 address (view only)

CAL

AUT

RST

Description xxx PPM Current CO or NO

OFF

YES

Table 3

concentration

Auto-baud will start and return to the main menu

Starts the manual serial configuration menu sequence

Will reset settings to factory default

MANUAL MENU OPTIONS

Menu Name Value

BAU 9600

19200

38400

57600

76800

115200

Description

Only available if AUT = OFF

PAR

STP

EVE

ODD

NON

Only available if AUT = OFF

Table 4

SENSOR REPLACEMENT

A replacement sensor is available from Dwyer Instruments, Inc.

For CO, order part number: A-505.

For NO

, order part number: A-506.

The address of the transmitter in Figure 9 is 127. This final value is determined by adding the individual values of the DIP switches together. The values for each DIP switch are shown below in Table 5. When adding the individual values for Figure 9,

0+64+32+16+8+4+2+1=127, which is the correct factory setting.

DIP SWITCH VALUES

Switch Positions

Address Value

128

Table 5

Another example would be if the desired address was 53. The only DIP switches in the

“ON” position would be switches 3, 4, 6, and 8 as shown in Figure 10 below. By adding the individual values of each switch in the “ON” position, 0+0+32+16+0+4+0+1=53, the desired address is obtained.

WARNING Sensors contain acid and are harmful if handled improperly. Do not attempt to open sensors. Sensors should be disposed of according to local laws.

Replacing The Sensor

1. Remove the cover plugs from the face of the unit and top cover. Locate the sensor,

see Figure 1. The sensor is mounted on three pin sockets. The circuit board is

either labeled “CO SENSOR” or “NO

SENSOR” underneath the sensor.

2. Remove and discard the used sensor.

3. Remove the shorting wire spring located at the bottom of the new sensor.

4. Install the new sensor into the three pin sockets.

5. The unit must be re-calibrated whenever a new sensor is installed.

6. Allow 30 minutes for the unit to come to temperature equilibrium prior to calibration.

The unit has internal temperature compensation, and the sensor must be at the

same temperature as the unit to calibrate properly.

NOTICE

1 2 3 4 5 6 7 8

Figure 10

The minimum possible address would be 0 when all DIP switches are in the “OFF” position, and the maximum possible address would be 255 when all DIP switches are in the “ON” position. When BACnet protocol is selected the transmitter only has valid address from 1 to 127. When Modbus ® communication protocol is selected the transmitter only has valid address from 1 to

247. Any address outside the selected protocol’s range will give an error.

CALIBRATION

Figure 8, located after Appendix III, shows how to set up a GSTC for calibration with an auxiliary display. An auxiliary display is required for calibration unless an LCD model of the GSTC was purchased. The procedure in Appendix IV shows how to set the range, and calibrate the span and zero adjustments.

MAINTENANCE/REPAIR

Upon final installation of the Series GSTC, no routine maintenance is required with the exception of sensor replacement and calibration. As with all electrochemical type gas sensors, routine calibration is required. It is recommended that units be recalibrated at 6 month intervals, to maintain the published accuracy, or as required by local ordinances or other requirements. The units will maintain 5% accuracy if they are re-calibrated at 12 month intervals.

Appendix II: BACnet Protocol

The GSTC supports objects that are listed below. Table 6 and Table 7 outlines each item.

SUPPORTED BACNET OBJECTS

Object Type

Device

Analog Input

Binary Value

Date Value

Dynamically

Creatable

Dynamically

Deletable

Table 6

Object

Identifier Object Name

607xxx

AI1

BV1

DV1

DV2

GSTC

CO Concentration

NO2 Concentration

Zero Sensor

Calibration Date

Replace Sensor Date

Except for the sensor replacement and calibration, the Series GSTC is not field serviceable and should be returned if repair is needed. Field repair should not be attempted and may void warranty.

This symbol indicates waste electrical products should not be disposed of with household waste. Please recycle where facilities exist. Check with your Local Authority or retailer for recycling advice.

WARRANTY/RETURN

Refer to “Terms and Conditions of Sales” in our catalog and on our website. Contact customer service to receive a Return Goods Authorization number before shipping the product back for repair. Be sure to include a brief description of the problem plus any additional application notes.

Appendix I: Setting the RS-485 Address

The address assignment is determined by adding the values for each of the switches that are in the “ON” position. The transmitter comes from the factory with all of the DIP switches in the “ON” position, except position 1 as shown in Figure 9 below.

1 2 3 4 5 6 7 8

Figure 9

OBJECT PROPERTIES

Property

Object Identifier

Default Value

607xxx

Object Name “GSTC 607xxx”

Object Type DEVICE (8)

Property Data Type

BACnetObjectIdentifier

CharacterString (32)

BACnetObjectType

Access

Read/Write

Read

System Status Operational (0)

Vendor Name

Vendor Identifier

Model Name

Firmware Revision

Application Software

Version

Location “”

“Dwyer

Instruments, Inc”

607

“GSTC-C” or

“GSTC-N”

“?.?”

BACnetDeviceStatus

CharacterString

Unsigned

CharacterString

CharacterString (32)

Read

Read/Write

Description

Protocol Version

Protocol Revision

Protocol Services

Supported

Protocol Object Types

Supported

Object List

Maximum APDU

Length Accepted

Segmentation

Supported

APDU Timeout

Number of APDU

Retries

Max Master

Max Info Frames

Devices Address

Binding

Database Revision

Serial Number (1000)

“CO Detector” or

“NO

Detector”

See pics

See Table 2

128

NO_SEGMENTA-

TION (3)

127

Empty

“xxxxxx”

CharacterString (32)

Unsigned

BACnetServicesSupported

BACnetObjectTypesSupported

BACnetArray

Unsigned

BACnetSegmentation

Unsigned

BACnetAddressBinding

Unsigned

CharacterString

Table 7

Read/Write

Read

Read/Write

Read

The default object identifier is 607xxx, where xxx is replaced by the address set by the DIP Switch SW1. The object identifier value will change as the address changes.

When a specific object identifier is written via BACnet, that value is stored and changes to the address will no longer affect the object identifier. The object name reflects the current object identifier. When a specific object name is written via BACnet, that value is stored and changes to the object identifier will no longer affect the object name.

Table 8 outlines the Analog Input (AI1) object which represents the current CO or NO

2 concentration reading in parts per million.

ANALOG INPUT

Property

Object Identifier

Object Name

Object Type

Present Value

Status Flags

Event State

Reliability

Out of Service

Units

Default Value

AI1

“CO Concentration” or

“NO2 Concentration”

ANALOG_INPUT (0)

Current reading

NORMAL (0)

NO_FAULT_DETECED(0)

FALSE (0)

Parts-per-million (96)

Table 8

Property Data Type

BACnetObjectIdentifier

CharacterString

BACnetObjectType

Real

BACnetStatusFlags

BACnetEventState

BACnetReliability

Boolean

BACnetEngineeringUnits

Access

Read

Read/Write

Read

Table 9 outlines the Binary Value (BV1) object which allows the sensor to be remotely zeroed. When set to “ACTIVE”, the zero function will attempt to recalibrate the zero point of the sensor.

BINARY VALUE

Property

Object Identifier

Object Name

Object Type

Present Value

Status Flags

Event State

Reliability

Out of Service

Default Value

BV1

“Zero Sensor”

BINARY VALUE (5)

NORMAL (0)

NO FAULT DETECTED (0)

FALSE (0)

Table 9

Property Data Type

BACnetObjectIdentifier

CharacterString

BACnetObjectType

Real

BACnetStatusFlags

BACnetEventState

BACnetReliability

Boolean

Access

Read

Read/Write

Read

Table 10 outlines the Date Value (DV1) object which stores the date when the sensor was last calibrated. Since the GSTC does not track time this value must be updated manually after calibration is performed in the field.

DATE VALUE

Property

Object Identifier

Object Name

Object Type

Present Value

Status Flags

Event State

Reliability

Out of Service

Default Value

DV1

“Calibration Date”

DATE VALUE (42)

????

{F,F,F,F}

NORMAL (0)

NO FAULT DETECTED (0)

FALSE (0)

Table 10

Property Data Type

BACnetObjectIdentifier

CharacterString

BACnetObjectType

BACnetBinaryPV

BACnetStatusFlags

BACnetEventState

BACnetReliability

Boolean

Access

Read

Read/Write

Read

Read/Write

Table 11 outlines the Replace Sensor Date (DV2) object which stores the suggested sensor replacement date. It is recommended to replace the sensor at specific intervals because the sensor degrades over time. The GSTC does not track time so this value must be updated manually after the sensor is replaced in the field.

REPLACE SENSOR DATE

Property

Object Identifier

Object Name

Object Type

Present Value

Status Flags

Event State

Reliability

Out of Service

Default Value

DV2

“Replace Sensor Date”

DATE VALUE (42)

????

{F,F,F,F}

NORMAL (0)

NO FAULT DETECTED (0)

FALSE (0)

Table 11

Property Data Type

BACnetObjectIdentifier

CharacterString

BACnetObjectType

BACnetBinaryPV

BACnetStatusFlags

BACnetEventState

BACnetReliability

Boolean

Access

Read

Read/Write

Read

Read/Write

BACnet Services

The GSTC supports the Device Communication Control Service BIBB. The option time duration in minutes is also supported. This device is configured with a password that must be provided to successfully execute the command. The password is “Dwyer”.

The GSTC also supports the Reinitialize Device Service BIBB. The supported device states are “COLDSTART” and “WARMSTART”. All other states return an error. This device is configured with a password that must be provided to successfully execute the command. The password is “Dwyer”.

Appendix III: Modbus ® Communication Protocol

The GSTC supports functions and input registers that are listed below. Table 12, Table

13, and Table 14 outline each item.

SUPPORTED MODBUS ® FUNCTIONS

Function Name

Read Holding Registers

Read Input Registers

Write Single Register

Write Multiple Registers

Function Code

Table 12

The string data type is read as a stream of ASCII characters with the first character sent in the MSB of the first register and the second character sent in the LSB of the first register and so on. If the string is shorter than the allotted size, the remaining bytes will be zero padded.

INPUT REGISTERS

Register

0001

Description

CO or NO in PPM

Concentration

Data Type

Unsigned 16 bit integer

1000-1009

1010-1013

1014-1017

Model Number String

Serial Number String

Firmware Version String

String

Table 13

Range

0 – 500 PPM CO,

0 – 100 (0 – 10.0) PPM

NO2

“GSTC-C” or

“GSTC-N”

“xxxxxx”

“?.?”

HOLDING REGISTERS

Register Description

0001

0500

Zero Sensor

Reboot device

Data Type

Unsigned 16bit integer

Value Range

0-1

0 or 1

0 - Do Nothing

1 - Warm Reset

Table 14

Writing 1 to the Zero Sensor register will re-zero the sensor just as if the user has pressed the zero pushbutton.

The Reboot Device register allows a Modbus ® communication protocol master to remotely request this device to perform a warm reset. When a value of 1 is written to this register the device will respond with success. The reset will take approximately 5 seconds after the command was received. Writing a value of 0 to this register has no effect.

Figure 8

Appendix IV: Menu Flowchart and Calibration

NOTE - WHEN IN THE MENU, THE

DISPLAY WILL RETURN TO THE

HOME POSITION IF NO KEY IS

PRESSED WITHIN 30 SECONDS.

HOME POSITION, UNIT READS GAS

CONCENTRATION PPM

SPAN

DIGIT

ZERO

VALUE

C O

P P M

PRESS AND HOLD ZERO AND SPAN

KEYS FOR 5 SECODNS TO ENTER

THE MAIN MENU.

MODBUS/BACNET ADDRESS.

VIEWABLE ONLY.

CALIBRATION

MODE

SPAN

DIGIT

SCROLL

SPAN

DIGIT SCROLL

COMMUNICATION

SETTINGS

FACTORY SETTING IS

AUTO BAUD ON.

SCROLL TO TOP

MENU, MODBUS/BACNET

ADDRESS

RESET UNIT

TO FACTORY

DEFAULTS

SPAN

DIGIT SCROLL

ZERO

VALUE

MOD

A DR

SCROLL

ZERO

VALUE

C O

P P M

SCROLL

ZERO

VALUE

PRESS ZERO AND SPAN TO ENTER CALIBRATION MODE

ZERO

VALUE

SPAN

DIGIT

C A L

ZERO

VALUE

PRESS THE ZERO KEY FOR 5 SECONDS. THE

ZERO VALUE IS STORED AND THE DISPLAY

SEQUENCES TO THE SPAN GAS CALIBRATION VALUE PRESS AND HOLD THE SPAN KEY FOR 5 SECONDS

C A L C A L

P P M

SPAN

DIGIT

PLACE THE UNIT IN AN AREA THAT CONTAINS FRESH

AIR (NO CO OR NO2 GAS). ALLOW 3 MINUTES TO

STABILIZE.

TO ADJUST THE DISPLAY TO SET

THE DESIRED SPAN CALIBRATION VALUE,

SPAN

DIGIT

PRESS THE DIGIT KEY TO SCROLL

THROUGH THE DIGITS. THE DIGITS WILL

BLINK AS THEY ARE SELECTED.

ZERO

VALUE

ADJUST THE VALUE OF THE DIGIT

USING THE VALUE KEY

HOOK UP THE UNIT TO THE SPAN CALIBRATION GAS

USING THE CALIBRATION ADAPTER A-507AS SHOW IN FIG. 8

SPAN GAS FLOW IS TO BE BETWEEN 0.5 TO 10. SLPM.

ALLOW GAS TO FLOW FOR AT LEAST 3 MINUTES.

S E N

C A L

DISPLAY READS “CAL” THEN “PASS” AND RETURNS TO HOME POSITION

IF THE SENSOR OUTPUT IS NO LONGER

SUFFICIENT FOR CALIBRATION, THEN

THE DISPLAY READS “BAD SEN”. THE

SENSOR MUST BE REPLACED

A UT

ZERO

VALUE

SPAN

DIGIT

PRESS AND HOLD ZERO AND SPAN UNTIL

“SET” TURNS ON

A UT

PRESS ZERO OR SPAN TO SWITCH

BETWEEN AUTO BAUD ON OR OFF

ZERO

VALUE

SPAN

DIGIT

PRESS AND HOLD ZERO AND SPAN UNTIL

“SET” TURNS OFF

ZERO

VALUE

AUTOBAUD MUST BE SET TO “NO” TO SET

BAUDRATE, PARITY AND STOP BIT SETTINGS

SPAN

DIGIT

SCROLL

ZERO

VALUE

SPAN

DIGIT

R S T

SET BAUD RATE

SET PARITY

SET STOP BITS

SCROLL

SPAN

DIGIT

SPAN

DIGIT SCROLL

SPAN

DIGIT SCROLL

ZERO

VALUE

B A U

SCROLL

ZERO

VALUE

P A R

SCROLL

PRESS AND HOLD ZERO AND SPAN UNTIL

“SET” TURNS OFF

PRESS AND HOLD ZERO AND SPAN UNTIL

“SET” TURNS ON

PRESS AND HOLD ZERO AND SPAN UNTIL

“SET” TURNS OFF

ZERO

VALUE

SPAN

DIGIT

B A U

ZERO

VALUE

USING ZERO AND SPAN KEYS, SET BAUDRATE

TO DESIRED VALUE

SPAN

DIGIT

PRESS ZERO OR SPAN TO SWITCH

BETWEEN NO PARITY OR EVEN OR

ODD PARITY

ZERO

VALUE

P A R

ZERO

VALUE

P A R

SPAN

DIGIT

SPAN

DIGIT

SCROLL

ZERO

VALUE

S T P

PRESS AND HOLD ZERO AND SPAN UNTIL

“SET” TURNS ON PRESS AND HOLD ZERO AND SPAN UNTIL

“SET” TURNS OFF

S T P

ZERO

VALUE

SPAN

DIGIT

ZERO

VALUE

USING ZERO AND SPAN KEYS, SET STOP BIT

TO 1 OR 2

SPAN

DIGIT

SCROLL

PRESS AND HOLD ZERO AND

SPAN UNTIL “SET” TURNS ON

ZERO

VALUE

R S T

ZERO

VALUE

SPAN

DIGIT

ZERO

VALUE

PRESS ZERO OR SPAN TO SWITCH

BETWEEN YES OR NO

R S T

SPAN

DIGIT

PRESS AND HOLD ZERO

AND SPAN UNTIL

“SET” TURNS OFF

ZERO

VALUE

SPAN

DIGIT

ZERO

VALUE

IF RESET IS SET TO YES, PRESSING ZERO AND SPAN

WILL CAUSE A FACTORY RESET, AND DISPLAY WILL

RETURN TO THE HOME POSITION

SPAN

DIGIT

IF RESET IS SET TO NO, PRESSING ZERO AND SPAN

NOTES

__________________________________________________________________________________________________________________________________________

Printed in U.S.A. 3/22

Modbus ® is a registered trademark of Schneider Automation, Inc.

FR# 443872-00 Rev. 8

DWYER INSTRUMENTS, INC.

P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A.

Phone: 219-879-8000

Fax: 219-872-9057 www.dwyer-inst.com

e-mail: [email protected]

Hello! I am an AI chatbot specifically trained to assist you with the Dwyer Series GSTC Specifications-Installation And Operating Instructions. I have thoroughly reviewed the document and can help you locate the exact information you need or explain the content in clear and simple terms. Whether you’re looking for guidance on specific features, troubleshooting steps, or general usage, feel free to ask your questions. The more details you provide about your concerns or needs, the more accurately and effectively I can assist you!