Dwyer Instruments GSTA, GSTC Operating Manual

Download

Bulletin AQ-GSTC

3-23/64

Series GSTC Carbon Monoxide/Nitrogen Dioxide Gas Transmitter

Specications - Installation and Operating Instructions

Wall mount

with LCD

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 to be used with almost any building management controller. The GSTC output is communicated over an RS-485 wire via BACnet or Modbus

To maximize the accuracy of the Series GSTC, the sensor can be eld-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 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

accordance with the job wiring diagram and in accordance with national and local electrical codes. Use copper conductors only.

NOTICE

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

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

ft above the oor.

• 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.

communication protocol recommend limiting the number of

Disconnect power supply before installation to prevent electrical shock and equipment damage. Make sure all connections are in

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.

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

The electrochemical sensors should be stored in an environment with a minimum humidity level of 20% RH. If the sensor dries out,

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

Wall mount

without LCD

communication protocol, allowing the transmitter

communication protocol.

Duct mount

3-45/64

[94.06]

3-1/8

[107.95]

4-17/32 [115.09]

5-7/64

[129.78]

SPECIFICATIONS

Sensor: Field replaceable electrochemical, 4 years typical lifespan. Range: CO: 0 to 500 PPM, NO2: 10 PPM.

Output Drift: <5% per year in air. Coverage Area: 5000 to 7500 sq ft typical. Accuracy: CO: 2% FS, NO2: 3% FS, at the time of calibration. Resolution: CO: 1 PPM; NO2: 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% NO2.

Span and Zero Adjustment: Via pushbutton, using optional A-449 display. Zero only via BACnet or Modbus

Housing: UV resistant glass lled polycarbonate. Output Signals: BACnet MS/TP or Modbus

communication protocol.

Power Requirements: 10 to 36 VDC or isolated 21.6 to 33 VAC. Electrical Connection: Removable terminal block, knock outs for conduit tting. Calibration: Via pushbuttons using A-449 auxiliary display. Span gas concentration is eld selectable. Enclosure Rating: IP64.

Weight: 1 lb (0.45 kg).

Agency Approvals: CE.

Figure 1 shows the location of the wiring terminal, 8 position DIP Switch SW1, used for

conguring the RS-485 address, the 4 position DIP Switch SW2, used for conguring

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 BACnet or Modbus

red LED will ash once periodically if the BACnet or Modbus address is set incorrectly or the red LED will ash twice periodically if the auto serial conguration is in progress.

communication protocol. The green LED indicates the unit is receiving a

Span

Sensor

DIP Switch

SW2

Wiring

Terminal

communication protocol.

communication protocol addressed to this specic device. The

2-15/64

[56.75]

Duct mountWall mount

RTU (switch selectable)

[85]

2-55/64

[73]

2-15/64

[57]

3-59/64

[100]

communication protocol

Zero

DIP Switch

SW1

Status

LEDs

DWYER INSTRUMENTS, INC.

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

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

Phone: 219/879-8000

Fax: 219/872-9057

Figure 1

www.dwyer-inst.com

e-mail: info@dwyermail.com

Wall Mounting

PWRCOM A(-)B(+)

PWRCOM A(-) B(+)

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 tting knock out and install conduit tting (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 oor. 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.

2 sensors should be mounted in the breathing zone, 4 to 6 ft (1.2 to 1.8 m) from the

oor. This is primarily because NO

2 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 oor

is an appropriate elevation to detect NO

2 gas.

Duct Mounting

Duct mounting kit includes an air ow pitot tube, air lter with barbed connections, two

short pieces of tubing, and one long piece of tubing.

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

tube.

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

air lter. 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.

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 conguration 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 conguration, shown in Figure 4, may be a

better choice.

1234

DEVICE

B(+) A(-) PWR

COM

ATTA CH SHIELDS TOGETHER W/WIRE NUT

TO NEXT

DEVICE

B(+) A(-) PWR

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 conguration.

1234

DEVICE

B(+) A(-)

COM

DEVICE

B(+) A(-) COM

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

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.

WIRING

NOTICE

Figure 2

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.

communication protocol installations should comply with

NOTICE

and Implementation Guide V1.02, Modbus

NOTICE

Modbus

communication protocol over Serial Line Specication

Modbus

Organization, Inc., 2006.

Communication wiring must be in a daisy-chain fashion. Star

connections are not permitted.

NOTICE

Cable shield must be connected to earth ground at one location

only.

Dip Switch Congurations

NETWORK BIAS

PROTOCOL NETWORK TERMINATION

Use DIP Switch SW1 (see Figure 5) to congure 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 default, the device is shipped with Modbus

communication protocol addresses range from 1 to 247. By

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 congure 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

Figure 5

To activate auto serial conguration, 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 ofine or away from the main network, it is necessary to generate the appropriate trafc in order to congure the serial communication whether

BACnet or Modbus

communication protocol is selected. While the serial conguration

is in progress, the device may not respond. The device may require multiple read

requests to complete the serial conguration process.

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

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.

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.

Use DIP Switch SW2 (see Figure 6) to congure other hardware and software options. Table 1 shows available options. Table 2 shows supported congurations for either

BACnet or Modbus

communication protocol.

1 2 3 4

Figure 6

DIP SWITCH SW2 FUNCTIONS Switch On Off

1 - Protocol 2 - B(+) Bias Resister 3 - A(-) Bias Resister 4 - Terminating Resister

Modbus

511Ω Pull-up to 5V 511Ω Pull-down to GND 120Ω between A(-) and B(+)

BACnet Pull-up not connected Pull-down not connected Open

Table 1

Auto Serial Conguration

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

setup menu.

SUPPORTED CONFIGURATIONS Protocol Supported Baud Rates Data Size Parity Stop Bits

BACnet 9600

19200

Modbus

38400 57600 76800

None 1

Even Odd None 2

115200

Table 2

Text

Secondary

Display

Text

Primary

Display

Numeric

Figure 7

Standard Menu Descriptions

BAC or MOD: Displays the RS-485 address CAL: Start user CO or NO2 calibration process

AUT: Auto serial conguration enabled

RST: Reset settings to factory default

Manual Menu Descriptions

BAU: Baud rate selection (only available if AUT = OFF) PAR: Parity selection (only available if AUT = OFF) STP: Stop bits selection (only available if AUT = OFF)

Menu Navigation

A menu owchart, 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 Description

BAC or MOD xxx ADR RS-485 address (view only) CAL xxx PPM Current CO or NO2 concentration AUT ON Auto-baud will start and return to the main menu

OFF Starts the manual serial conguration menu sequence

RST NO

YES Will reset settings to factory default

Table 3

MANUAL MENU OPTIONS Menu Name Value Description

9600 19200

BAU

38400 57600

Only available if AUT = OFF

76800 115200 EVE

PAR

ODD

Only available if AUT = OFF

NON

STP

1 2

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.

2, order part number: A-506.

For NO

The address of the transmitter in Figure 9 is 127. This nal 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 Value112826433241658647281

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

2 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.

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 nal 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.

Except for the sensor replacement and calibration, the Series GSTC is not eld

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.

1 2 3 4 5 6 7 8

Figure 10

NOTICE

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.

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

Dynamically Creatable

No No

Dynamically Deletable

No No

Object Identier Object Name

607xxx AI1

GSTC CO Concentration

NO2 Concentration Binary Value Date Value

No No

BV1 DV1 DV2

Zero Sensor

Calibration Date

Replace Sensor Date

Table 6

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 Default Value Property Data Type Access

Object Identier

Object Name

Object Type

System Status

Vendor Name

607xxx

“GSTC 607xxx”

DEVICE (8)

Operational (0)

“Dwyer

BACnetObjectIdentier

CharacterString (32)

BACnetObjectType

BACnetDeviceStatus

CharacterString

Read/Write

Read

Instruments, Inc”

Vendor Identier

Model Name

607 “GSTC-C” or

Unsigned CharacterString

Read Read

“GSTC-N” Firmware Revision Application Software

“?.?”

CharacterString CharacterString

Read

Read Version Location

Description

Protocol Version Protocol Revision Protocol Services

“”

“CO Detector” or

2 Detector”

“NO 1 12 See pics

CharacterString (32)

Unsigned Unsigned BACnetServicesSupported

Read/Write

Read

Read Supported Protocol Object Types Supported Object List Maximum APDU

See Table 2

See Table 2 128

BACnetObjectTypesSupported BACnetArray Unsigned

Read

Read Length Accepted Segmentation Supported APDU Timeout Number of APDU

NO_SEGMENTATION (3) 0 0

BACnetSegmentation

Unsigned Unsigned

Read

Read Retries Max Master Max Info Frames Devices Address

127 1 Empty

Unsigned Unsigned BACnetAddressBinding

Read/Write

Read

Read Binding Database Revision Serial Number (1000)

1 “xxxxxx”

Unsigned CharacterString

Read

Table 7

The default object identier is 607xxx, where xxx is replaced by the address set by the DIP Switch SW1. The object identier value will change as the address changes. When a specic object identier is written via BACnet, that value is stored and changes to the address will no longer affect the object identier. The object name reects the current object identier. When a specic object name is written via BACnet, that value is stored and changes to the object identier will no longer affect the object name.

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 Default Value Property Data Type Access

Object Identier

Object Name Object Type Present Value Status Flags Event State Reliability Out of Service

BV1 “Zero Sensor” BINARY VALUE (5)

0 0 NORMAL (0) NO FAULT DETECTED (0) FALSE (0)

BACnetObjectIdentier

CharacterString BACnetObjectType Real BACnetStatusFlags BACnetEventState BACnetReliability Boolean

Read Read Read Read Read Read Read Read/Write Read

Table 9

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 eld.

DATE VALUE

Property Default Value Property Data Type Access

Object Identier

Object Name Object Type Present Value Status Flags Event State Reliability Out of Service

DV1 “Calibration Date” DATE VALUE (42) ???? {F,F,F,F} NORMAL (0) NO FAULT DETECTED (0) FALSE (0)

BACnetObjectIdentier

CharacterString BACnetObjectType BACnetBinaryPV BACnetStatusFlags BACnetEventState BACnetReliability Boolean

Read Read Read Read/Write Read Read Read Read/Write

Table 10

Table 11 outlines the Replace Sensor Date (DV2) object which stores the suggested

sensor replacement date. It is recommended to replace the sensor at specic 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 eld.

REPLACE SENSOR DATE

Property Default Value Property Data Type Access

Object Identier

Object Name Object Type Present Value Status Flags Event State Reliability Out of Service

DV2 “Replace Sensor Date” DATE VALUE (42) ???? {F,F,F,F} NORMAL (0) NO FAULT DETECTED (0) FALSE (0)

BACnetObjectIdentier

CharacterString BACnetObjectType BACnetBinaryPV BACnetStatusFlags BACnetEventState BACnetReliability Boolean

Read Read Read Read/Write Read Read Read Read/Write

Table 11

Table 8 outlines the Analog Input (AI1) object which represents the current CO or NO concentration reading in parts per million.

ANALOG INPUT

Property Default Value Property Data Type Access

Object Identier

Object Name

AI1 “CO Concentration” or

BACnetObjectIdentier

CharacterString

Read Read

“NO2 Concentration” Object Type Present Value Status Flags Event State Reliability Out of Service Units

ANALOG_INPUT (0)

Current reading

NORMAL (0)

NO_FAULT_DETECED(0)

FALSE (0)

Parts-per-million (96)

BACnetObjectType Real BACnetStatusFlags BACnetEventState BACnetReliability Boolean BACnetEngineeringUnits

Read Read Read Read Read Read/Write Read

Table 8

BACnet Services

The GSTC supports the Device Communication Control Service BIBB. The option time

duration in minutes is also supported. This device is congured 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 congured 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 Function Code

Read Holding Registers Read Input Registers Write Single Register Write Multiple Registers

03 04 06 16

Table 12

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

will be zero padded.

INPUT REGISTERS

0001

CO or NO2 Concentration in PPM

Unsigned 16 bit integer

0 – 500 PPM CO, 0 – 100 (0 – 10.0) PPM NO2

1000-1009

Model Number String

String

“GSTC-C” or

“GSTC-N” 1010-1013 1014-1017

Serial Number String Firmware Version String

String String

“xxxxxx”

“?.?”

Table 13

Figure 8

HOLDING REGISTERS

0001 0500

Zero Sensor Reboot device

Unsigned 16bit integer Unsigned 16bit integer

0-1 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.

Appendix IV: Menu Flowchart and Calibration

NOTE - WHEN IN THE MENU, THE

MODBUS/BACNET VIEW

DISPLAY WILL RETURN TO THE HOME POSITION IF NO KEY IS PRESSED WITHIN 30 SECONDS.

HOME POSITION, UNIT READS GAS CONCENTRATION PPM

PPM

SPAN

ZERO

DIGIT

VALUE

PRESS AND HOLD ZERO AND SPAN KEYS FOR 5 SECODNS TO ENTER THE MAIN MENU.

ADDRESS.

ABLE ONLY.

SPAN DIGIT

CALIBRATION MODE

COMMUNICATION SETTINGS FACTORY SETTING IS AUTO BAUD ON.

SCROLL TO TOP MENU, MODBUS/BACNET ADDRESS

RESET UNIT TO FACTORY DEFAULTS

ZERO

VALUE

SPAN DIGIT

SCROLL

SPAN DIGIT

SCROLL

ADR

SCROLL

PPM

SCROLL

MOD

ZERO

PRESS ZERO AND SPAN TO ENTER CALIBRATION MODE

VALUE

ZERO

VALUE

SPAN DIGIT

PLACE THE UNIT IN AN AREA THAT CONTAINS FRESH AIR (NO CO OR NO2 GAS). ALLOW 3 MINUTES TO STABILIZE.

ZERO VALUE

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

AUT

ZERO

VALUE

SPAN DIGIT

SCROLL

ZERO

SPAN DIGIT

VALUE

SET BAUDRAT E

RST

SPAN DIGIT

SETPARITY

SETSTOPBITS

SCROLL

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

ZERO

VALUE

SPAN DIGIT

SCROLL

PRESS THE ZERO KEY FOR 5 SECONDS. THE ZERO VALUE IS STORED AND THE DISPLAY SEQUENCES TO THE SPAN GAS CALIBRATION VALUE

CAL

ZERO

VALUE

TO ADJUST THE DISPLAY TO SET THE DESIRED SPAN CALIBRATION VALUE,

PRESS THE DIGIT KEY TO SCROLL

SPAN

THROUGH THE DIGITS. THE DIGITS WILL

DIGIT

BLINK AS THEY ARE SELECTED.

ADJUST THE VALUE OF THE DIGIT

ZERO

USING THE VALUE KEY

VALUE

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.

PRESS ZERO OR SPAN TO SWITCH BETWEEN AUTO BAUD ON OR OFF

ZERO

AUT

VALUE

SPAN DIGIT

AUTOBAUD MUST BE SET TO “NO” TO SET BAUDRATE, PARITY AND STOP BIT SETTINGS

SCROLL

ZERO

VALUE

BAU

SCROLL

ZERO

VALUE

PAR

SCROLL

ZERO

VALUE

STPSTP

ZERO

VALUE

RST

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

ZERO

VALUE

SPAN DIGIT

USING ZERO AND SPAN KEYS, SET BAUDRATE TO DESIRED VALUE

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

ZERO

VALUE

SPAN DIGIT

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

ZERO VALUE

SPAN DIGIT

USING ZERO AND SPAN KEYS, SET STOP BIT TO 1 OR 2

PRESS ZERO OR SPAN TO SWITCH BETWEEN YES OR NO

ZERO VALUE

SPAN DIGIT

CAL

PPM

PRESS AND HOLD THE SPAN KEY FOR 5 SECONDS

CAL

SPAN DIGIT

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

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

AUT

ZERO VALUE

SPAN DIGIT

SCROLL

PRESS AND HOLD ZERO AND SPAN UNTIL

BAU

PAR

RST

“SET” TURNS OFF

ZERO VALUE

SPAN DIGIT

PRESS ZERO OR SPAN TO SWITCH BETWEEN NO PARITY OR EVEN OR ODD PARITY

ZERO

VALUE

SPAN DIGIT

“SET” TURNS OFF

ZERO

VALUE

SPAN DIGIT

IF RESET IS SET TO YES, PRESSING ZERO AND SPAN WILL CAUSE A FACTORY RESET, AND DISPLAY WILL

ZERO

RETURN TO THE HOME POSITION

VALUE

IF RESET IS SET TO NO, PRESSING ZERO AND SPAN SPAN DIGIT

IF THE SENSOR OUTPUT IS NO LONGER SUFFICIENT FOR CALIBRATION, THEN THE DISPLAY READS “BAD SEN”. THE SENSOR MUST BE REPLACED

SEN

AUT

PAR

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

ZERO

VALUE

SPAN DIGIT

CAL

NOTES

__________________________________________________________________________________________________________________________________________

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: info@dwyermail.com

Dwyer Instruments GSTA, GSTC Operating Manual

Specifications and Main Features

Frequently Asked Questions

User Manual