Critical Environment Technologies cGas Detector User manual

Rev. A | 2019.07
www.critical-environment.com
cGas Detector Digital Transmitter
Operation Manual

2 © 2019 All rights reserved. Data subject to change without notice.
cGas Detector Digital Transmitter - Operation Manual Rev. A | 2019.07
TABLE OF CONTENTS
1 POLICIES..........................................................................................................5
1.1 Important Note................................................................................................5
1.2Warranty Policy................................................................................................6
1.3 Service Policy...................................................................................................7
1.4 Copyrights........................................................................................................8
1.5 Disclaimer........................................................................................................8
1.6 Revisions..........................................................................................................8
2 INTRODUCTION .............................................................................................9
2.1 General Description..........................................................................................9
2.2 Key Features...................................................................................................10
3 INSTRUMENT SPECIFICATIONS .................................................................11
3.1Technical Specications..................................................................................11
3.2 Enclosure Dimensions....................................................................................14
4 SENSOR SPECIFICATIONS...........................................................................15
4.1 Single Channel Gas Sensor Options................................................................15
4.2 Dual Channel Gas Sensor Options...................................................................17
4.3 Calibration Extending Firmware (CEF) and Sensor Aging................................18
5 INSTRUMENT FEATURES.............................................................................18
5.1 Exterior Enclosure ..........................................................................................18
5.2 Interior System Layout...................................................................................19
6 SYSTEM OPERATION & CONFIGURATION................................................20
6.1 Navigating the Menu Structure......................................................................20
6.2 Accessing the Menu with Passcodes...............................................................21

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6.3 Display Settings .............................................................................................22
6.3.1 Adjust Display Brightness................................................................................23
6.3.2 Display Congurations ....................................................................................23
6.3.3 Display or Hide Line 1 and/or 2 .......................................................................24
6.4 Alarm Status, Fault Detection and Communication Failure Notications........25
6.5 Setting Channel Alarm Setpoints, Direction and Hysteresis............................26
6.6 Enable / Disable Channels..............................................................................29
6.7 Change Units (degC or degF) ofTemperature Readings..................................30
6.8Temperature and/or Relative Humidity Oset................................................31
6.9Test Functions ................................................................................................32
7 MODBUS AND BACNET CONFIGURATION...............................................34
7.1 Changing CommunicationType (Modbus®/BACnet®) in the Field ..................34
7.2 Conguring Modbus® Settings.......................................................................35
7.2.1 Change Modbus® MAC Address.......................................................................35
7.2.2 Change Baud Rate...........................................................................................36
7.2.3 Modbus® Holding Registers ............................................................................37
7.3 Conguring BACnet® Settings........................................................................37
7.3.1 Change BACnet® MAC Address ........................................................................37
7.3.2 Change BACnet® Instance ID ...........................................................................38
7.3.3 Change BACnet® Baud Rate.............................................................................38
7.3.4 BACnet® PICS Information...............................................................................39
8 PLUG & PLAY SMART SENSOR REPLACEMENT.......................................46
8.1 How to Replace or Add a New Smart Sensor Board ........................................46
8.2 Read from Sensor...........................................................................................47
8.3Write to Sensor...............................................................................................49

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cGas Detector Digital Transmitter - Operation Manual Rev. A | 2019.07
9 CALIBRATION................................................................................................49
9.1 Calibration Specications...............................................................................49
9.1.1 Gas..................................................................................................................49
9.1.2 Regulators & Flow...........................................................................................50
9.1.3 Adapters..........................................................................................................50
9.1.4 Calibration Frequency .....................................................................................50
9.1.5 Gas Testing Frequency (Bump Testing)............................................................51
9.1.6 Sticky Gases.....................................................................................................51
9.2 Calibrating the Internal Sensor(s) ..................................................................51
9.2.1 Set Calibration GasValue.................................................................................51
9.2.2 Zero (Null) Calibration.....................................................................................53
9.2.3 Span Calibration..............................................................................................54
9.3Troubleshooting Calibration...........................................................................56
9.3.1 Calibration Adapter Plug Doesn’t Fit................................................................56
9.3.2 Zero Fault ........................................................................................................56
9.3.3 Span (Calibration) Fault...................................................................................57
9.3.4 Zero Override...................................................................................................57
9.3.5 Span Override..................................................................................................57
9.4 Calibrating an Oxygen Sensor ........................................................................58
10 ACCESSORIES .............................................................................................60
10.1 Splash Guard (Option -S)..............................................................................60
10.2 Calibration Adapter Clip ”Cal Clip”................................................................60
10.3 Splash Guard for Sticky Gases (Option -SN) ..................................................61
10.4 Metal Protective Guard ................................................................................62
10.5 Calibration Kit..............................................................................................62
11 MAINTENANCE ..........................................................................................63
12 TROUBLE SHOOTING ................................................................................64

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1 POLICIES
1.1 Important Note
Read and understand this manual prior to using this instrument. Carefully read the warranty policy,
service policy, notices, disclaimers and revisions on the following pages.
This product must be installed by a qualied electrician or factory trained technician and according
to instructions indicated in this manual.This instrument should be inspected and calibrated
regularly by a qualied and trained technician.
This instrument has not been designed to be intrinsically safe. For your safety, do not use it in
classied hazardous areas (explosion-rated environments).
INSTRUMENT SERIAL NUMBER:
______________________________________________________
PURCHASE DATE:
______________________________________________________
PURCHASED FROM:
______________________________________________________

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cGas Detector Digital Transmitter - Operation Manual Rev. A | 2019.07
1.2 Warranty Policy
Critical Environment Technologies Canada Inc. (the manufacturer) warrants this gas monitoring
instrument, (excluding sensors, battery packs, batteries, pumps and lters), to be free from defects
in materials and workmanship for a period of two years from the date of purchase from our
facility.The sensors have a warranty period of one year on a pro-rated basis from the date
of purchase from our facility.This warranty is limited to the mechanics of the physical sensor
components and as such, should the sensor become defective within this warranty period, we
will repair or replace it at our discretion.This warranty does not extend to sensors that have been
poisoned by external compounds such as, but not limited to, extreme gas concentrations, paint
fumes, excessive dust, debris, etc. or to sensors that have been improperly zeroed, calibrated or
altered in any way. If it is determined within 90 days of purchase that a sensor is malfunctioning
or unable to remain calibrated due to no fault of its placement or treatment, the instrument may be
sent back to the factory for a free calibration service.
The warranty status may be aected if the instrument has not been operated, calibrated or
maintained as per the instructions in the instrument’s Operation Manual or if the instrument has
been abused, damaged or altered in any way. This instrument is only to be used for purposes stated
herein.The manufacturer is not liable for auxiliary interfaced equipment or consequential damage.
Due to ongoing research, development and product testing, the manufacturer reserves the right to
change specications without notice.The information contained herein is based on data considered
accurate. However, no warranty is expressed or implied regarding the accuracy of this data.
All goods must be shipped to the manufacturer by prepaid freight. All returned goods (whether
under warranty or not) must be pre-authorized by obtaining a return merchandise authorization
(RMA) number. Contact the manufacturer for an RMA number and the procedures required for
product transport.

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1.3 Service Policy
CETCI maintains an instrument service facility at the factory. Some CETCI distributors / agents may
also have repair facilities; however, CETCI assumes no liability for service performed by anyone
other than CETCI personnel.
Repairs are warranted for 90 days after date of shipment (sensors have individual warranties).
Should your instrument require non-warranty repair, you may contact the distributor from whom it
was purchased or you may contact CETCI directly.
Prior to shipping equipment to CETCI, contact our oce for an RMA #. All returned goods must be
accompanied with an RMA number.
If CETCI is to do the repair work, you may send the instrument, prepaid, to:
Attention: Service Department
Critical Environment Technologies Canada Inc.
Unit 145, 7391 Vantage Way
Delta, BC, V4G 1M3
Always include your Returned Merchandise Authorization (RMA) number, address, telephone
number, contact name, shipping / billing information, and a description of the defect as you
perceive it.You will be contacted with a cost estimate for expected repairs, prior to the performance
of any service work.
For liability reasons, CETCI has a policy of performing all needed repairs to restore the instrument to
full operating condition.
Pack the equipment well (in its original packing if possible), as we cannot be held responsible for
any damage incurred during shipping to our facility.

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cGas Detector Digital Transmitter - Operation Manual Rev. A | 2019.07
1.4 Copyrights
This manual is subject to copyright protection; all rights are reserved. Under international and
domestic copyright laws, this manual may not be copied or translated, in whole or in part, in any
manner or format, without the written permission of CETCI.
Modbus® is a registered trademark of Gould Inc. Corporation.
BACnet® is a registered trademark of American Society of Heating, Refrigeration and Air
Conditioning (ASHRAE).
1.5 Disclaimer
Under no circumstances will CETCI be liable for any claims, losses or damages resulting from or
arising out of the repair or modication of this equipment by a party other than CETCI service
technicians, or by operation or use of the equipment other than in accordance with the printed
instructions contained within this manual or if the equipment has been improperly maintained or
subjected to neglect or accident. Any of the forgoing will void the warranty.
Under most local electrical codes, low voltage wires cannot be run within the same conduit as line
voltage wires. It is CETCI policy that all wiring of our products meet this requirement.
It is CETCI policy that all wiring be within properly grounded (earth or safety) conduit.
1.6 Revisions
This manual was written and published by CETCI.The manufacturer makes no warranty or
representation, expressed or implied including any warranty of merchantability or tness for
purpose, with respect to this manual.
All information contained in this manual is believed to be true and accurate at the time of printing.
However, as part of its continuing eorts to improve its products and their documentation, the

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Rev. A | 2019.07 cGas Detector Digital Transmitter - Operation Manual
manufacturer reserves the right to make changes at any time without notice. In addition, due to
improvements made to our products, there may be information in this manual that does not exist
in the version of the product the user has. Should you detect any error or omission in this manual,
or should you want to inquire regarding upgrading the device’s rmware, please contact CETCI at
the following address:
Critical Environment Technologies Canada Inc.
Unit 145, 7391VantageWay, Delta, BC, V4G 1M3, Canada
Toll Free: +1.877.940.8741
Telephone: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.critical-environment.com
In no event will CETCI, its ocers or employees be liable for any direct, special, incidental or
consequential damages resulting from any defect in any manual, even if advised of the possibility
of such damages.
2 INTRODUCTION
2.1 General Description
Thank you for purchasing our cGas Detector Transmitter. The cGas Detector is a one or two channel
gas detection transmitter that oers exible customization options with the purpose of meeting
your specic application and budgetary requirements. Ideal for monitoring toxic, combustible and
refrigerant gases in non-hazardous (non-explosion rated) environments such as enclosed parking
facilities, commercial HVAC, greenhouses, recreational facilities, refrigeration plants, manufacturing
plants and other light industrial applications.
The sensors utilized in this device are accurate enough to measure to Occupational Health & Safety

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cGas Detector Digital Transmitter - Operation Manual Rev. A | 2019.07
(OHS) hazardous levels for toxic gases. The transmitter operates by diusion.
2.2 Key Features
• 1 or 2 gas channel operation
• User congurable Modbus® RS-485 RTU or BACnet® MS/TP communication protocols for
communication with a Controller or Building Automation System (BAS)
• Easy Plug & Play Smart sensor replacement at end of life
• Customizable sensor and option combinations to meet specic application requirements
• 24 volt DC or (ground referenced) AC power
• 4-conductor shielded network wiring (daisy-chain)
• In eld upgradable rmware/conguration via USB connection
• Bright LCD display
• Option -LT: Low temperature package for improved usability in cold environments
• Option -RHT: Relative Humidity and Temperature sensor (digital CO and CO2models only)
• Option -S: Splash guard, factory installed, IP54 rated enclosure
• Option -SN: Splash guard, factory installed, for Cl2, HCI or O3sensors only
• Standard water / dust tight, corrosion resistant enclosure (drip proof)
• Copper coated interior to reduce RF interference
• RoHS compliant circuit boards
• Auto resetting fuse
NOTE: Some gas sensor types and Options are restricted to certain models.
If after reading through the manual, you have any questions, please do not hesitate to contact our
service department for technical support.

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3 INSTRUMENT SPECIFICATIONS
3.1 Technical Specications
MECHANICAL
Enclosure ABS / Polycarbonate, IP54 rating with splash guard installed.
Copper coated interior to reduce RF interference.
Weight 400 g / 14 oz
Size 127 mm x 127 mm x 71 mm / 5.0 in x 5.0 in x 2.8 in
USER INTERFACE
Display (standard)
2-line by 16 character graphic LCD, black on green, text
prompting for calibration operation and fault indications. Installer
congurable to suppress reading display.
Display (Option -LT)
Optional OLED display for improved usability in low temperature
applications, 2-line by 16 character, yellow on black, text
prompting for calibration operation and fault indications. Installer
congurable to suppress reading display.
USB Port Internal port for USB memory stick connection for eld
conguration/rmware upgrades
Push Buttons Initiate calibration and menu options with internal UP, DOWN and
ENTER push buttons
Audible Alarm none

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cGas Detector Digital Transmitter - Operation Manual Rev. A | 2019.07
ELECTRICAL
Power Requirement
16 - 30VDC, 3 W, Class 2
12 - 27VAC, 50-60 Hz, 3VA, Class 2
24V recommended.
Digital Wiring VDC orVAC (ground referenced) four-conductor shielded 16 AWG
stranded within conduit, network wiring (daisy-chain)
Fuses Automatic resetting thermal
INPUT/OUTPUT
Communication
Modbus® RTU (version
1.1b3) RS-485
Modbus® ID: 100 (default, congurable)
Baud rate: 19,200 (default, congurable)
Data bits: 8
Start bits: 1
Stop bits: 1
Parity: none
Communication
BACnet® MS/TP (version
1 rev 14) RS-485
BACnet® MS/TP; ANSI/ASHRAE standard 135 BACnet®
Communication protocol: 135-2012
Baud Rate: 76,800 (default)
Base Address: 270 (default)
MAC Address: 100 (default)
Parity: no parity
Stop bits: 1
Data bits: 8

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Rev. A | 2019.07 cGas Detector Digital Transmitter - Operation Manual
RH andTemperature
(Option -RHT) Available for CO2 and CO models only
ENVIRONMENTAL
OperatingTemperature 0°C to 40°C / 32°F to 104°F (standard)
-40°C to 40°C / -40°F to 104°F (with Option -LT)
Operating Humidity 15 - 90% RH non-condensing
Pollution Degree Degree 2
Altitude below 2,000 m
CERTIFICATION
Model: CGAS-D-XXX
S/N: CGASD1807B00010
Rating: 16-30 VDC, 3W, Class 2
12-27 VAC, 50-60 Hz, 3VA, Class 2
CERTIFIED FOR ELECTRIC SHOCK & ELECTRICAL FIRE HAZARD ONLY. LA CERTIFICATION ACNOR
COUVRE UNIQUEMENT LES RISQUES DE CHOC ELECTRIQUE ET D’INCENDIE D’ORIGINE ELECTRIQUE.
Conforms to: CSA-C22.2 No. 205-12, UL508 (Edition 18):2018
Conforms to: EMC Directive 2014/30/EU, EN 50270:2015,Type 1, EN61010
Conforms to: FCC. This device complies with part 15 of the FCC Rules, Operation is subject to
the following two conditions: (1)This device may not cause harmful interference, and (2) this
device must accept any interference received, including interference that may cause undesired
operation.

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cGas Detector Digital Transmitter - Operation Manual Rev. A | 2019.07
3.2 Enclosure Dimensions
Above dimensions are shown with optional splash guard.Without splash guard, thickness is
71 mm / 2.8 in.The area required for enclosure door to be open 90 degrees is 178 mm / 7.0 in or
254 mm / 10.0 in for fully open. With the optional splash guard installed, the enclosure is IP54
rated.
NOTE: During calibration, the sensor response time will be slower with a splash guard installed.

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Rev. A | 2019.07 cGas Detector Digital Transmitter - Operation Manual
4 SENSOR SPECIFICATIONS
4.1 Single Channel Gas Sensor Options
Electrochemical Sensors Part Numbers Range Lifespan
Ammonia (NH3) CGAS-D-NH3 0 - 500 ppm ± 2 years
Carbon Monoxide (CO) CGAS-D-LCO 0 - 200 ppm ± 6 years
Chlorine (Cl2) CGAS-D-CL2 0 - 5.0 ppm ± 3 years
Chlorine Dioxide (ClO2) CGAS-D-CLO2 0 - 1 ppm ± 2 years
Ethylene (C2H4) CGAS-D-C2H4 0 - 200 ppm ± 2 years
Ethylene Oxide (C2H4O) CGAS-D-EETO 0 - 20 ppm ± 2 years
Fluorine (F2) CGAS-D-F2 0 - 1 ppm ± 2 years
Formaldehyde (CH2O) CGAS-D-CH2O 0 - 5 ppm ± 2 years
Hydrogen (H2) CGAS-D-EH2 0 - 2,000 ppm ± 2 years
Hydrogen Sulphide (H2S) CGAS-D-H2S 0 - 50 ppm ± 2 years
Hydrogen Chloride (HCl) CGAS-D-HCL 0 - 30 ppm ± 2 years
Hydrogen Cyanide (HCN) CGAS-D-HCN 0 - 30 ppm ± 2 years
Hydrogen Fluoride (HF) CGAS-D-HF 0 - 10 ppm ± 2 years
Nitric Oxide (NO) CGAS-D-NO 0 - 100 ppm ± 2 years
Nitrogen Dioxide (NO2) CGAS-D-NO2 0 - 10 ppm ± 6 years
Oxygen (O2) CGAS-D-O2 0 - 25% Vol ± 3 years
Ozone (O3) CGAS-D-O3 0 - 2 ppm ± 2 years

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cGas Detector Digital Transmitter - Operation Manual Rev. A | 2019.07
Phosphine (PH3) CGAS-D-PH3 0 - 5 ppm ± 2 years
Silane (SiH4) CGAS-D-SIH4 0 - 20 ppm ± 2 years
Sulphur Dioxide (SO2) CGAS-D-SO2 0 - 20 ppm ± 2 years
Refrigerant Sensors Part Numbers Range Lifespan
Refrigerant R22 CGAS-D-SR22 0 - 2,000 ppm ± 5 years
Refrigerant R134A CGAS-D-SR134A 0 - 2,000 ppm ± 5 years
Refrigerant R402A CGAS-D-SR402A 0 - 2,000 ppm ± 5 years
Refrigerant R404A CGAS-D-SR404A 0 - 2,000 ppm ± 5 years
Refrigerant R407A CGAS-D-SR407C 0 - 2,000 ppm ± 5 years
Refrigerant R410A CGAS-D-SR410A 0 - 2,000 ppm ± 5 years
Refrigerant R422D CGAS-D-SR422D 0 - 2,000 ppm ± 5 years
Refrigerant R438A CGAS-D-SR438A 0 - 2,000 ppm ± 5 years
Refrigerant R507A CGAS-D-SR507A 0 - 2,000 ppm ± 5 years
TVOCs CGAS-D-STVOC 0 - 500 ppm ± 5 years
Catalytic Sensors Part Numbers Range
Hydrogen (H2) CGAS-D-CH2-100 0 - 100% LEL ± 5 years
Methane (CH4) CGAS-D-CCH4-100 0 - 100% LEL ± 5 years
Propane (C3H8) CGAS-D-CC3H8-100 0 - 100% LEL ± 5 years

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PID Sensors Part Numbers Range
TVOC CGAS-D-SPL 0 - 30 ppm usage /
application
dependent
TVOC CGAS-D-SPH 0 - 300 ppm
Infrared Sensors Part Numbers Range
Carbon Dioxide (CO2)CGAS-D-CO2-5K 0 - 5,000 ppm ± 6 years
CGAS-D-CO2-5% 0 - 5% vol
4.2 Dual Channel Gas Sensor Options
Two Internal
Electrochemical Sensors Part Numbers Range Lifespan
Carbon Monoxide (CO) and
Nitrogen Dioxide (NO2)CGAS-D-LCO-NO2 0 - 200 ppm 0 - 10 ppm ± 6 years
Carbon Monoxide (CO) and
Ethylene (C2H4)CGAS-D-LCO-C2H4 0 - 200 ppm ± 6 years ± 2 years
Carbon Monoxide (CO) and
Hydrogen Sulphide (H2S) CGAS-D-LCO-H2S 0 - 200 ppm 0 - 50 ppm
± 6 years
± 2 years
Carbon Monoxide (CO) and
Oxygen (O2)CGAS-D-LCO-O2 0 - 200 ppm 0 - 25% vol
± 6 years
± 3 years
Carbon Monoxide (CO) and
Nitric Oxide (NO) CGAS-D-LCO-NO 0 - 200 ppm 0 - 100 ppm 2-3 years

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cGas Detector Digital Transmitter - Operation Manual Rev. A | 2019.07
Hydrogen Sulphide (H2S) and
Sulphur Dioxide (SO2)CGAS-D-H2S-SO2 0 - 50 ppm 0 - 20 ppm 2+ years
4.5 Calibration Extending Firmware (CEF) and Sensor
Aging
The cGas Detector with integral electrochemical sensor(s) have been programmed with our CEF.
This rmware takes into consideration the aging of the electrochemical CO and NO2sensors so that
less frequent calibrations are required in less-critical applications such as parking garages. The
system tracks the age of the sensor and automatically compensates for the reduced output of the
sensor as it ages.
5 INSTRUMENT FEATURES
5.1 Exterior Enclosure
Œ
Œ
Ž
•
•
•

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Rev. A | 2019.07 cGas Detector Digital Transmitter - Operation Manual
NUMBER FEATURE FUNCTION
ŒDoor Hinge Secures door to base and allows easy
opening and closing
•Display LCD display (standard display)
ŽSensor Opening Allows gas diusion into sensor
•Door Screw Secures door shut
•Lock Slot For security padlock or tie
5.2 Interior System Layout
•
•
ys yo
Ž
•
Œ
Œ
Œ
NUMBER FEATURE FUNCTION
ŒProgramming Buttons
Access menu options and program functions using
buttons inside the enclosure. (Arrow up, Enter, Arrow
down)
A
B

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cGas Detector Digital Transmitter - Operation Manual Rev. A | 2019.07
•RS-485 Communication
Terminals
Pluggable power and signal terminal for connection
to controller and next transmitter.
ŽUSB Connection For rmware and conguration upgrades
•Termination Resistor Network termination resistor.“IN”position includes
120 ohm resistor.
•Sockets for sensors and
Options boards
Sensor boards and Options boards plug into the main
board using these sockets
6 SYSTEM OPERATION & CONFIGURATION
The cGas Detector continuously monitors target gas concentrations on one or two congured
channels. It must be connected to a controller, control panel or BAS / BMS / DDC system; the cGas
Detector is not a standalone gas detection system.
6.1 Navigating the Menu Structure
The three programming push-buttons inside the enclosure are used to navigate through the cGas
Detector menu structure. Refer to Section 5.1 Exterior Enclosure for location photo.
ENTER begins a process or moves you to the next screen in the same menu.
The UP or DOWN buttons are used to enter characters/numbers and to navigate to the next menu
item.
A line under a character or number indicates that is the space into which you are entering a
character or number. Use the ENTER button to move to the next space. Or use the UP or DOWN
button to change the value in that space.