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Marathon Sensors Inc.
Oxymit ™ Transmitter
Operators Manual
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F200060 Revision: 00 04/18/2001 01 04/23/2001 02 05/08/2001 03 09/19/2001 04 11/01/2001 05 11/21/2001 06 04/19/2002 07 10/30/2002 08 11/13/2002 09 11/06/2003 10 12/03/2003 11 09/30/2004 12 04/04/2005 13 04/11/2005 14 11/14/2006 COPYRIGHT © 2004 MARATHON SENSORS INC. 3100 East Kemper Road, Cincinnati, Ohio 45241 1-800-547-1055 (513) 772-1000 FAX: (513) 326-7090 All trademarks used in this publication are duly marked and the sole property of their respective owners. No attempt at trademark or copy
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Table of Contents GENERAL DESCRIPTION............................................................................................................................ 2 SAFETY SUMMARY......................................................................................................................................3 CONNECTIONS .............................................................................................................................................. 3 GROUNDING AND SHIELDING .....
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NOTE: Please specify the following parameters when ordering a transmitter; process type, process range (%, ppm), thermocouple type, temperature scale F/C, analog output 1 process and scale, analog output 2 process and scale. Typical Oxygen Transmitter Calibration (F840030) Calibration Measured Value or Output / Units Function Input Cold Junction Room Temp °F Thermocouple 800°F (B type) °F min standard t/c type Thermocouple 3000°F (B type) °F max standard t/c type Millivolt 0.0 mV Millivolts Mill
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General Description The Oxymit ™ Transmitter has been designed to work as an analog or digital interface for any zirconia based oxygen probe used to track dew point, carbon potential, or oxygen. The transmitter connects to the temperature and millivolts outputs of an oxygen probe and can produce analog outputs proportional to the selected process value. The features available are: Isolated inputs for thermocouple and probe millivolt 24 bit Sigma-Delta ADC for inputs. Serial EEPROM to store
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Safety Summary All cautions and instructions that appear in this manual must be complied with to prevent personnel injury or damage to the Probe Transmitter or connected equipment. The specified limits of this equipment must not be exceeded. If these limits are exceeded or if this instrument is used in a manner not intended by Marathon Sensors Inc., damage to this instrument or connected devices could occur. Do not connect this device directly to AC motors, valves, or other actuators. All AC ala
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The next figure shows a schematic representation of the Probe Transmitter and typical connections required in the field. Figure 3 Schematic Connections Grounding and Shielding To minimize the pick-up of electrical noise, the low voltage DC connections and the sensor input wiring should be routed away from high-current power cables. Where it is impractical to do this, use shielded cables with the shield grounded at the Probe Transmitter enclosure ground as show above. Parameter Selections The fol
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Table 1 Process Parameters Parameter Name Selection Units or Options Range Default PROCESS TYPE %O2 CARBON, DPT, %O2, MV CARB PROC FACT 150 0 to 1000 DEWPT PROC FACT 150 0 to 1000 OXYGEN EXPON 0002 POWER OF TEN 0 to 31 TC TYPE B B, C, E, J, K, N, NNM, R, S, T Process Type Selecting the process type determines what type of calculation the Smart Transmitter is going to do based on the probe millivolt and probe temperature inputs. The default process value for the Smart Transmitter is %O2 with an e
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Oxygen Exponent The range of oxygen is factory configured using the oxygen exponent number. Percent oxygen is the standard setting where the oxygen exponent is set to 2 and the output range is 0.00% to 20.9%. For a part per million (ppm) range the exponent would be set to 6 and the -6 -6 output range of 0.00 X 10 to 99.99 X 10 . TC Type The following table shows the available thermocouple types and the ranges. BOLD indicates the typical oxygen default. Thermocouple Zero ºF Zero °C Span ºF Span °
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Table 2 Analog Outputs Parameter Oxygen Possible Possible Name Default Options Ranges OUTPUT 1 O2 O2, CARBON, O2 = 0 – 9999 MODE DEWPT, TEMP, LIN, %C = 0.00 – 2.55 0–20.9% PROG DP = -99.9 – 212.0 4-20mA Temp = -999 – 3000 LIN = -999 – 9999 PROG = 0 – 4095 OUTPUT 2 TEMP O2, CARBON, O2 = 0 – 9999 MODE DEWPT, TEMP, LIN, %C = 0.00 – 2.55 800-3000°F PROG DP = -99.9 – 212.0 4-20mA Temp = -999 – 3000 LIN = -999 – 9999 PROG = 0 – 4095 NOTE: SEE PAGE 4 FOR TYPICAL CALIBRATION VALUES. Calibration The Smar
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Process Variable Calculations The transmitter has a selectable process calculation for percent carbon, percent oxygen, or dewpoint. The following equations are used to derive these values; Percent Oxygen 20.95 %O2 = ----------------------- (E/0.0215*Tk) e Where: E = probe millivolts, Tk = probe temperature in degrees Kelvin. The 20.95 is the %O2 in air. Percent Carbon ((E-786)/(0.043102*Tk)) e %C = 5.102 --------------------------------------------------- (29*PF + 400)+ ((E-786)/(0.043102*Tk)) e
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Communications The Transmitter is capable of digital communications using the Modbus protocol. This is possible by connecting to the half duplex RS-485 terminals using a shielded twisted pair. Modbus The MODBUS protocol describes an industrial communications and distributed control system (DCS) that integrates PLCs computers, terminals, and other monitoring, sensing, and control devices. MODBUS is a Master/Slave communications protocol, whereby one device, (the Master), controls all serial activ
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byte received will be an address. The follow command message structure is used, where T is the required character delay. Response from the instrument is based on the command. T1,T2,T3 ADDRESS FUNCTION DATA CHECKSUM T1,T2,T3 8-BITS 8-BITS N X 8-BITS 16-BITS Address Field The address field immediately follows the beginning of the frame and consists of 8-bits. These bits indicate the user assigned address of the slave device that is to receive the message sent by the attached master. Each slave mus
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The following is an example of a function 03 call for data at memory location 03. The value returned by the instrument is the hex value 1E. Transmit from Host or Master Address Cmd Reg Reg Count Count CRC CRC HI LO HI LO HI LO 01 03 00 03 00 01 74 0A Response from Transmitter Address Cmd Byte Byte Data Data CRC CRC Count Count HI LO HI Lo HI LO 01 03 00 02 00 1E 38 4C Note that all the values are interpreted as hexadecimal values. The CRC calculation is based on the A001 polynomial for RTU Modbu
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Memory Map NOTE: Modbus refers to the hexadecimal register location. These parameters are formatted as unsigned 16 bit integers. Any real number such as temperature can be evaluated as a signed number, other parameters are bit mapped words that must be evaluated as single bits are bit groups. BLOCK 0 HEX DEC PARAMETER DESCRIPTION READ/WRITE 00 0 Not used READ ONLY LOW BYTE - TIMER CONTROL 01 1 TIME CONTROL READ/WRITE SIOSET BIT 0 – Timer Disabled (0), Timer Enabled (1) BIT 1 – 7 SPARE HIGH BYTE
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BLOCK 0 HEX DEC PARAMETER DESCRIPTION READ/WRITE DEFAULT = 150 05 5 EVENT LOW BYTE – INPUT EVENT READ/WRITE LDLN CONFIGURATION Bits 0 – 3 0000 = None 0001 = Auto Mode Selected 0010 = Remote Setpoint Selected 0011 = Acknowledge alarms 0100 = Timer Hold 0101 = Timer End 0110 = Timer Start 0111 = Start probe test 1000 = Process hold Bits 4 – 7 not used. UPPER BYTE – LOAD LINE LOW BYTE – COLD JUNCTION TRIM 06 6 CJTRM HADR COLD JUNCTION TRIM (unsigned integer) RANGE = –128 TO +127 WHERE 1 COUNT = 1 D
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BLOCK 0 HEX DEC PARAMETER DESCRIPTION READ/WRITE BITS 0 - 4 OXYGEN EXPONENT RANGE = 0 to 31, where 2 = % and 6 = ppm DEFAULT = 2 BITS 5 - 6 DISPLAY DECIMAL PLACE where: 0 = no decimal point in display 1 = Display XXX.X 2 = Display XX.XX 3 = Display X.XXX DEFAULT = 0 BITS 8 – 12 REDOX METAL NUMBER RANGE = 0 – 14 DEFAULT = 0 BITS 13 – 15 SPARE 0A 10 FAULT FAULT BIT MAP READ ONLY BIT 0 = Temperature Input Open BIT 1 = MV Input Open BIT 2 = Range of input is low BIT 3 = Range of input is high BIT 4
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BLOCK 0 HEX DEC PARAMETER DESCRIPTION READ/WRITE HIGH BYTE, ANALOG OUTPUT 2 BITS 8 – 12 0000 = N/A 0001 = Temperature 0010 = Linear Input A 0011 = Carbon value 0100 = Dewpoint value 0101 = Oxygen value 0110 = Redox value 0111 = Output Power 1000 = Control Output 1 1001 = Control Output 2 1010 = Linear Input B 1011 = Programmable* *For Reference Number and Programmable , write required output value into DACV2, where DACV2 = 0 is minimum output and DACV2 = 4096 is maximum output. BITS 13 – 15 SPAR
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BLOCK 0 HEX DEC PARAMETER DESCRIPTION READ/WRITE source value is based on the selection in ASRC upper byte where 14 20 SPARE SPARE READ/WRITE 15 21 SPARE SPARE READ/WRITE 16 22 SPARE SPARE READ/WRITE 17 23 TEMPFIL Temperature Input Filter in seconds READ/WRITE Range = 0 to 3276. The higher the number the faster the reading update. DEFAULT = 1000 BLOCK 1 HEX DEC PARAMETER DESCRIPTION READ/WRITE 18 24 MVFIL Millivolt Input Filter in seconds READ/WRITE Range = 0 to 3276. The higher the number the f
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BLOCK 1 HEX DEC PARAMETER DESCRIPTION READ/WRITE 22 20 DACV2 ANALOG OUTPUT 2 READ/WRITE 0 to 4095 is 4 to 20 ma In dual mode 4mA = - 100, 12mA = 0, 20mA = +100 23 35 SPARE SPARE 24 36 SPARE SPARE 25 37 SPARE SPARE 26 38 SPARE SPARE 27 39 SPARE SPARE 28 40 SPARE SPARE 29 41 SPARE SPARE 2A 42 SPARE SPARE 2B 43 SPARE SPARE 2C 44 SPARE SPARE 2D 45 SPARE SPARE 2E 46 SPARE SPARE 2F 47 SPARE SPARE Page 17 of 23 11/14/2006 Rev. 14
