Dwyer Instruments CMT Series User manual

SERIES CMT
CARBON MONOXIDE GAS
TRANSMITTER
INSTALLATION
OPERATION AND MAINTENANCE
MANUAL
DWYER INTRUMENTS, INC.
PO BOX 373, MICHIGAN CITY, IN. 46360 USA
PHONE: [phone] FAX: [phone]
Web: www.dwyer-inst.com

Operation And Maintenance Manual
83850-001-003 RF Jan 2009
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CMT Configuration:
Default Settings
Factory User
Settings Settings
1. Signal 4 mA See Table Below ________________
20 mA See Table Below ________________
2. Password 0017 ________________
3.* Relay 1 Actuation Ena led ________________
4. Relay 1 Setpoint (Actuation) See Table Below ________________
5. Relay 1 Release Point See Table Below ________________
(De-Actuation)
6. Relay 1 Actuation Delay 0 Minutes ________________
7. Relay 1 De-Actuation Delay 0 Minutes ________________
8.* Relay 2 Actuation Ena led ________________
9. Relay 2 Setpoint (Actuation) See Table Below ________________
10. Relay 2 Release Point See Table Below ________________
(De-Actuation)
11. Relay 2 Actuation Delay 0 Minutes ________________
12. Relay 2 De-Actuation Delay 0 Minutes ________________
13 Communication Protocol Optomux ________________
14. Digital Address 0001 ________________
15 Baud Rate 4800 ________________
Note: Relay setpoints are included in the software; however relays are optional.
Rela 1 (Warning)
(If Applicable)
Rela 2 (Alarm)
(If Applicable)
Gas T pe
4 mA
Default
20 mA
Default Setpoint Release Point Setpoint Release Point
NO
2
0 ppm 6.0 ppm 1.0 ppm 0.8 ppm 3.0 ppm 2.5 ppm
CO 0 ppm 125 ppm 25 ppm 20 ppm 50 ppm 40 ppm
NO 0 ppm 100 ppm 25 ppm 20 ppm 50 ppm 40 ppm
NH
3
0 ppm 50 ppm 25 ppm 20 ppm 35 ppm 30 ppm
O
2
0% 25% 1 .50%
Decreasing 20.00% 23.00% Increasing 22.00%

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Table Of Contents
Default Settings...........................................................................................................................................1
1. PRINCIPLES OF OPERATION........................................................................................................3
1.1 DISPLAY.............................................................................................................................................3
1.2 KEYPAD AND FUNCTION CONFIGURATION .........................................................................................3
1.3 PASSWORD .........................................................................................................................................4
1.4 OUTPUT SIGNALS ...............................................................................................................................4
1.5 METER JACKS ....................................................................................................................................4
1.6 SIGNAL AND DISPLAY RANGE ............................................................................................................4
1.7 OPTIONAL RELAY PACKAGE...............................................................................................................5
1.8 DEFAULT CONDITIONS .......................................................................................................................5
1. SENSING AND CALIBRATION...............................................................................................................5
1.9.1 Calibration ...................................................................................................................................5
1.9.2 Implications for Troubleshooting.................................................................................................5
2. FUNCTION AND CONFIGURATION .............................................................................................6
2.1 MENU STRUCTURE AND USE..............................................................................................................6
2.2 CONFIGURATION AND CALIBRATION ..................................................................................................7
2.3 HARDWARE CONFIGURATION...........................................................................................................13
2.3.1 Output Signals ............................................................................................................................13
2.3.2 RS 485 End of Line Wiring and Termination ............................................................................13
2.3.3 Battery ........................................................................................................................................14
2.4 GAS CALIBRATION ...........................................................................................................................14
2.4.1 Equipment Required ...................................................................................................................14
2.4.2 Procedure ...................................................................................................................................15
2.4.3 Calibration Errors......................................................................................................................15
3. FAULTS..............................................................................................................................................16
3.1 SELF-CHECK FAULTS........................................................................................................................16
3.2 HARDWARE FAULTS.........................................................................................................................18
4. WIRING AND POWER SUPPLIES ................................................................................................19

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CMT Operating Manual
1. Principles of Operation
1.1 Display
The display module is a 2-line by 8-character LCD. Standard reading in operation is
Gas Type
xxx Units
1.2 Keypad and Function Configuration
Relay settings and other configurable items are accessed through the keypad and menu
display.
The keypad is a set of 3 buttons recessed along the upper right side of the enclosure. It is
not necessary to open the cover for use of the keypad. Access to the menus is password
restricted. Press any key for 3 seconds to enter the menus. (See below for details)
Figure 1 CMT Internal View - Features

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1.3 Password
Factor preset default password is 0017.
Password can be changed. RECORD PASSWORD IN A SECURE PLACE. If the
password is lost, the unit must be returned to Dw er to be reset
1.4 Output Signals
Options are 4-20 milliamp or 2-10 VDC linear. Choose the option by moving the jumper
on JP3. On over range concentrations the signal can exceed the range slightly.
I MPORTANT : Voltage monitoring should be into a monitor with at least 50 000 ohms
input impedance. Voltage monitoring is not recommended over long distances, as
these signals are more susceptible to induced noise than current signals
1.5 eter Jacks
Test pads accepting standard test probes are provided on the circuit card. These are
labeled SigA, SigB and Common
To test milliamp signals measure:
• SigA to Common shorts to internal ground.
• SigA to SigB without interrupting signal to monitor
To Test voltage signals measure:
• SigB to Common.
1.6 Signal and Display Range
It is important to distinguish between Signal Range (often called Span) and Display
Range.
Figure 2 Signal Configuration JP3

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 Display Range is the range of concentrations the unit is capable of displaying
(which is the same concentration it will report on the digital communications).
The display range varies with the gas type.
 Signal Range is the assignment of the 4 to 20 mA signal. Default assignment of 4
mA is zero concentration. The default setting for 20 mA varies with the gas type.
The Signal range is fully adjustable within the limits imposed by the Display Range. Both
the 4 mA level and the 20 mA level can be reassigned through the menu system. Please
note that this adjustment does not change the measurement resolution.
1.7 Optional Relay Package
Two relays are supplied; single pole double throw (SPDT; Form C) 1 Amp. Dry contacts
only. Configuration allows setpoint adjustment for actuation point, dead-band, and
delays, increasing or decreasing concentrations. The relay settings have the same range as
the Display Range, and are independent of Signal Range.
1.8 Default Conditions
Default conditions are those conditions, which occur:
• During the short wait state on Power On.
• In Fault status.
• In the menu tree.
In these situations the following conditions hold:
• Signal set at 4.0 milliamps (2 Volts)
• Relays set non-energized.
• Digital communications report 0; no alarm status and 4 milliamp equivalent
signal.
1.9 Sensing and Calibration
Sensor type: Various electrochemical.
1.9.1 Calibration
The sensor is strongly linear in it’s response to gas. It is therefore straightforward to
calibrate. Two gases are needed for calibration: Zero gas (clean air) and an appropriate
span gas. Adjustment is by one potentiometer on the circuit board.
1.9.2 Implications for Troubleshooting
The microprocessor will detect various component faults and out-of-range conditions,
and drop the output signal to 0.0 milliamps. When a fault is detected, both relays will be
deactivated as well. However, it cannot detect simple out of calibration conditions, which
can only be detected by applying a gas standard.

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2. Function and Configuration
2.1 enu Structure and Use
Note: While the keypad functions are available without opening the case. It is necessary
to open the case to apply the calibration gases. The ‘keypad’ switches are located in the
upper right side of the enclosure. See Figure 1 Page 3.
Displa : The display is 2 line by 8 character alphanumeric. The top line contains the
feature name and the second contains the variable.
Ke pad: The keypad consists of three (3) pushbutton switches.
S1 Scroll Up
S2 Scroll Down
S3 Enter/Accept
Displa at Turn-On:
The display shows the following for about 2 seconds:
QEL M-5
Vx.xx Ry
Where: x.xx = the Software Version
y = the Software Revision
Followed for about 2 seconds by:
ElectrCh
Vx.xx Ry
Where: ElectrCh = Electrochemical
x.xx = the Sensor Algorithm Version
y = the Sensor Algorithm Revision
Displa in Operation: The display shows
GAS
xxx Units
Where GAS will show the target gas, and xxx is concentration of
the gas. Units may be either ppm (parts per million) or %.

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Note: Should the concentration equal or drop below an internal
value, the unit will flash "CALIBR" on display line 2 every 8
seconds.
Menu Activation: Press and hold any key for 3 seconds to enter the menu tree.
Menu Scrolling: Use the scroll buttons to scroll up and down through the menu tree.
Data Entr Mode: Enter the data entry mode by pressing S3 (Enter) while displaying
any feature. This mode is indicated by an * (asterisk) at the right of the variable, and
indicates that the variable may be changed by scrolling. Press S3 (Accept) to save result
and return to menu tree. While in data entry mode, the Up and Down keys perform an
automatic key repeat while the key is held in.
Password: The first item on entering the menu tree is a Password request. The display is
0000, the default password is 0017. The * appears, indicating that a number can be
entered and accepted. This number can be changed by the user (see below).
Fault: In case of faults, the display will read FAULT and a fault code in the bottom LCD
line (see below). Signal will drop to 0 milliamps.
See section 3 below for more information on faults.
2.2 Configuration and Calibration
Note: The user has control of all variables, including calibration gas concentrations,
alarm settings and signal range (both 4 milliamp and 20 milliamp) assignments. It is
important to note that these must be chosen carefully with regard to calibration. Zero
calibration is done through a menu option, Span calibration is done though a
potentiometer on the circuit card, not through the menu system, and so it is possible to
perform the adjustment without the menu system; however, the menus do offer disabling
of output actuation.
1. Press any key for 3 seconds to enter menu system
Gas T pe Displa
Range
Warning
(Rela 1)
W-Deact Alarm
(Rela 2)
A-Deact 20 mA
Default
NO
2
0-10.0 ppm 1.0 ppm 0.8 ppm 3.0 ppm 2.5 ppm 6.0 ppm
CO 0-250 ppm 25 ppm 20 ppm 50 ppm 40 ppm 125 ppm
NO 0-200 ppm 25 ppm 20 ppm 50 ppm 40 ppm 100 ppm
NH
3
0-100 ppm 25 ppm 20 ppm 35 ppm 30 ppm 50 ppm
1 .50% 23.00%
Decreasing Increasing
25%O
2
0-25 % 20.00% 22.00%
Table
1
Default Settings

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2. Password Control
PASSWORD
0000 *
Press up/down to choose correct password and accept.
3. Factory Settings Sub-menu Branch
FACTORY
Settings
This function is for factory setup and test only.
4. Rela 1 Sub-menu Branch
RELAY 1
Settings
Press Enter to proceed to the Relay 1 Settings sub-menu (press down/up to skip
Relay 1 Settings and go to next/previous menu item or sub-menu).
4.1 RELAY
Enable
Press Enter to change. “*” Indicates to use scroll buttons to toggle between
Enable, Disable or Latching. Press Accept when done.
Note that this disables the physical relay, but not the setpoint. Setpoint
actuation status will still be transmitted on the digital communications link
if queried.
When the “Latching” option is selected, the relay will not de-actuate
unless it is cancelled by pressing one of the keyboard buttons. The relay
will only reset if the alarm situation has dissipated.
Enable is the default.
Press Down button to continue through Relay 1 Settings branch. Press Up
to return to Main Menu (and Relay 1 Settings sub-menu branch).
4.2 Actuation Setpoint
ACTUATE
00XX ppm (or %)

Operation And Maintenance Manual
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Choose the concentration of Gas. Up/Down scrolls up/down in the Relay 1
Settings branch.
4.3. De-Actuation Setpoint
DEACT
00XX ppm (or %)
Choose the concentration of the gas at which you want the alarm condition
to stop.
Note: If the De-Actuation Setpoint is set at a higher concentration
than the Actuation setpoint, then the setpoint function reverses and
actuates on decreasing concentrations.
Note: The software will not allow the user to set Actuation = De-actuation.
If Actuation is set equal to De-actuation, the Actuation Setpoint will be
adjusted upward by 10% of display range automatically before saving the
new settings.
4.4 Actuation Delay.
ACT-TIME
00 min
Adjust the amount of time delayed before the relay is actuated after the
Actuation Setpoint is reached. A maximum of 60 minutes is possible,
adjustable in 5-minute increments.
Default is 0000.
4.5 De-Actuation Delay.
DEACTIME
00 min
Adjust the amount of time delayed before the relay is released after the De-
Actuation setpoint is reached. A maximum of 60 minutes is possible,
adjustable in 5-minute increments. Default is 00.
4.6 Buzzer.
BUZZER