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OLCT 700/710 TP

 

OLCT 700/710 TP Instruction Manual 

                                Rev. C.1 

Page 27 of 45 

 

4.

 

RS-485 Modbus™ Protocol 

 
OLCT 700/710 gas detectors feature Modbus™ compatible communications protocol and are addressable 
via the program mode. Communication is two wire, half duplex 485, 9600 baud, 8 data bits, 1 stop bit, no 
parity, with the detector set up as a slave device. A master controller up to 1200 meters (4000 feet) away 
can theoretically poll up to 256 different detectors. This number may not be realistic in harsh environments 
where noise and/or wiring conditions would make it impractical to place so many devices on the same pair 
of  wires.  If  a  multi-point  system  is  being  utilized,  each  detector  should  be  set  for  a  different  address. 
Typical address settings are: 01, 02, 03, 04, 05, 06, 07, 08, 09, 0A, 0B, 0C, 0D, 0E, 0F, 10, 11…etc. 
 
Detector RS-485 ID numbers are factory default to 01. These can be changed in the field via the Operator 
Interface described in Section 3.5.5 Set Serial ID. 
 
The  following  section  explains  the  details  of  the  Modbus™  protocol  that  the  OLCT  700/710  detector 
supports. 
 
Code 03 - Read Holding Registers is the only code supported by the transmitter. Each transmitter contains 
6 holding registers which reflect its current status. 
 

Table 3: 

Modbus™ Registers 

FC 

REG 

Content Description 

R/W 

Content Definition 

 

 

 

 

Value 

Meaning 

Range 

03 

40000 

Device Type 

OLCT 700/710 Detector 

 

03 
06 

40001 
40001 

Read Detectable Range

1,2 

Write Detectable Range 

R/W 

100 
10000 

For 0-100 
For 0-10000

2

 

FP – Read only 
TP – 20, 50, 100, 200 
IR – 0 to 10000 

03 

40002 

 

Read Concentration

3,2

 

 

1000 

Bound by range. If > range, this value is 
in fault. 

 

03 
06 

40003 
40003                 

Read AutoSpan Level

4,2

 

Write AutoSpan Level 

R/W 

50 

Span gas at 50 

FP – 5% to 95% of Range 
(40001) 
TP – 2% to 50% of Range 
(40001) 
IR – 5% to 95% of Range 
(40001) 

03 

40004 

Read Sensor Life 

85 

For 85% sensor life 

 

03 

40005 

Read Fault Status Bits

5

 

0x0001 
0x0002 
0x0004 
0x0008 
0x0010 
0x0020 
0x0040 
0x0080 
0x0100 
0x0200 
0x0400 
0x0800 
0x1000 
0x2000 
0x4000 
0x8000 

Global Fault 
Auto Span Fault 
Temperature Fault 
4-20mA Fault 
Input Voltage Fault 
Memory Fault 
Processor Fault 
Clearing Fault 
Stability Fault 
Range Fault 
Sensor Fault 
Zero Fault 
Sensor Fault 2 
<reserved> 
In Calibration 
Communication Error 

 

03 

40006 

Read Model # 

1, 2, 3, 4, 5 

DM, FP, IR, TP, PID respectively 

 

03 

40007 

Read Days Since Cal 

29 

29days 

 

03 

40008 

4-20 Current Output 

mA x100 

400 

4.00mA 

Range 

03 

40009 

Read Input Voltage 

V x100 

2400 

24.00V 

 

03 

40010 

Read Temperature 

28 

28 °C 

 

03/

06 

40011 

Special #1 

R/W 

 

Function dependent on value of 40006 
(See Special Register Table 4) 

 

03/

06 

40012 

Special #2 

R/W 

 

Function dependent on value of 40006 
(See Special Register Table 4) 

 

03 

40013 

Special #3 

 

Function dependent on value of 40006 
(See Special Register Table 4) 

 

03/

06 

40014 

Special #4 

R/W 

 

Function defendant on value of 40006 
(See Special Register Table 4) 

 

Summary of Contents for 700 TP Series

Page 1: ...OLCT 700 710 TP The Fixed Gas Detection Experts Instruction Manual 700 TP Series Hydrogen Sulfide Detector Solid State Sensor Part Number NP700TPIMEN Revision C 1 OLCT 700 OLCT 710...

Page 2: ...ithout the written consent of Oldham S A S All of the information that is provided in this document is accurate to the best of our knowledge As a result of continuous research and development the spec...

Page 3: ...al Start Up 12 3 Operation 15 3 1 Programming Magnet Operating Instructions 15 3 2 Operator Interface 16 3 3 Normal Operation 17 3 4 Calibration Mode AutoSpan 17 3 5 Program Mode 19 3 6 Program Featur...

Page 4: ...Figure 6 Outline and Mounting Dimensions 8 Figure 7 Typical Installation 9 Figure 8 Detector Wire Connections 12 Figure 9 Magnetic Programming Tool 15 Figure 10 Magnetic Programming Switches 15 Figur...

Page 5: ...lated or used as the basis for the manufacture or sale of OLDHAM equipment or for any other reason without the prior consent of OLDHAM Warning This is not a contractual document In the best interest o...

Page 6: ...OLCT 700 710 TP vi OLCT 700 710 TP This page has been left blank intentionally...

Page 7: ...1 ATEX Operational Guidelines for Safe Use Solid State H2S Sensor Technology The sensor technology is a patented solid state mixed metal oxide semiconductor The sensor consists of two thin films a te...

Page 8: ...Module ITM is a fully encapsulated microprocessor based package that accepts a plug in field replaceable H2S sensor Circuit functions include LED display magnetic programming switches a linear 4 20mA...

Page 9: ...s sensor is a field proven plug in replaceable type sensor with over sized gold plated connections that eliminate corrosion problems It can be accessed and replaced in the field very easily by releasi...

Page 10: ...OLCT 700 710 TP Page 4 of 45 Rev C 1 OLCT 700 710 TP Instruction Manual This page has been left blank intentionally...

Page 11: ...erating temperature range equal or greater than 80 C 3 The threaded joints may be lubricated to maintain flameproof protection Only non hardening lubricants or non corrosive agents having no volatile...

Page 12: ...determined by facility engineers with experience in similar processes Ventilation Normal ventilation or prevailing wind conditions can dictate efficient location of gas detectors in a manner where th...

Page 13: ...presence of such contaminants in an area does not preclude the use of this H2S sensor technology although it is likely that the sensor lifetime will be shorter as a result Use of this sensor in these...

Page 14: ...specifications The sensor shall always be in contact with ambient air Therefore do not cover the detector do not paint detector assemblies avoid dust accumulation The OLCT 700 710 TP should be vertic...

Page 15: ...s and to avoid damage due to water leakage Refer to Figure 7 and Figure 8 for proper electrical installation Figure 7 Typical Installation NOTE The Oldham Warranty does not cover water damage resultin...

Page 16: ...nd selected termination resistor Table 2 Wire Gauge vs Distance AWG Wire Dia Cross Section Meters Feet Over Current Protection 22 0 65 mm 0 32 mm 700 2080 3A 20 0 8 mm 0 5 mm 1120 3350 5A 18 1 0 mm 0...

Page 17: ...into the OLCT 710 2 7 2 Terminal Connections CAUTION Do not apply System power to the detector until all wiring is properly terminated and openings are properly closed a Remove the junction box cover...

Page 18: ...uires 24 gauge two conductor shielded twisted pair cable between detector and host PC General Cable Commodore part number ZO16P0022189 is recommended NOTE Install a 120 resistor across A B terminals o...

Page 19: ...cies NOTE Span gas bottles contain 0 humidity and this ultra low humidity condition will cause inaccurate readings when used to calibrate a detector To prevent this error Oldham prescribes the use of...

Page 20: ...OLCT 700 710 TP Page 14 of 45 Rev C 1 OLCT 700 710 TP Instruction Manual...

Page 21: ...t when the arrow prompt appears For momentary contact use the programming magnet is briefly held over a switch location The 3 and 10 second holds are generally used to enter calibration program menus...

Page 22: ...w refer to the complete Software Flow Chart in Figure 11 Normal Operation Current Reading and Fault Status Calibration Mode AutoSpan Program Mode View Sensor Status Sensor Model Type Current Software...

Page 23: ...2 M Set Serial ID Figure 11 OLCT 700 710 TP Software Flowchart 3 3 Normal Operation In normal operation the OLCT 700 710 Display continuously shows the current detector reading which will normally app...

Page 24: ...rough e below for AutoSpan calibration a Verify that the AutoSpan Level is equal to the Calibration Span Gas Concentration refer to View Sensor Status in Section 3 5 2 If the AutoSpan Level is not equ...

Page 25: ...nd will not clear the fault until a successful AutoSpan is completed e AutoSpan calibration is complete NOTE 1 If the sensor fails the minimum signal change criteria a Range Fault will be declared and...

Page 26: ...ional 3 4 seconds to enter the selected menu item If there is no magnet activity while the menu item text is scrolling typically 4 repeated text scrolls the OLCT 700 710 will automatically revert to N...

Page 27: ...se the AutoSpan Level until the correct level is displayed When the correct level is achieved hold the magnet over PGM1 or PGM2 for 3 4 seconds to accept the new value The display will scroll Level Sa...

Page 28: ...ch H2S sensor to the optimum operating temperature NOTE The function is performed during factory calibration of each OLCT 700 710 TP detector assembly and is not necessary during installation However...

Page 29: ...ion and calibration data from memory and revert to factory default values This may be required if the settings have been configured improperly and a known reference point needs to be re established to...

Page 30: ...n the View Sensor Status menu After 180 days an AutoSpan Fault will be declared 3 6 2 Fault Diagnostic Failsafe Features Fail Safe Fault Supervision OLCT 700 710 TP MicroSafe detectors are designed fo...

Page 31: ...until the fault condition is resolved Processor Fault If the OLCT 700 710 has any unrecoverable run time errors a Processor Fault is declared A Processor Fault will cause a Fault Detected message to s...

Page 32: ...ure Fault occurs the 4 20mA signal remains operational AutoSpan Fault If 180 days has elapsed since the last successful AutoSpan an AutoSpan Fault will be generated An AutoSpan Fault will cause the Fa...

Page 33: ...Meaning Range 03 40000 Device Type R 8 OLCT 700 710 Detector 03 06 40001 40001 Read Detectable Range1 2 Write Detectable Range R W 100 10000 For 0 100 For 0 100002 FP Read only TP 20 50 100 200 IR 0...

Page 34: ...Reading times one x 10 with units in notation string for Low Range 1 Gas Reading times one x 100 with units in notation string for Low Range 2 4 Span Gas must be less than or equal to Detectable Range...

Page 35: ...of water accumulation or Terminal Block corrosion 5 3 Condensation Prevention Packet A moisture condensation packet should be installed in every explosion proof Junction Box The moisture condensation...

Page 36: ...guard Unthread and remove the Bottom Housing from the ITM d Gently pull the plug in H2S sensor cell out of the ITM Orient the new plug in sensor so that it matches with the female connector pins It ma...

Page 37: ...l reading range should be 10 100 k ohms For sensors with an X in the serial number the normal reading range should be 75 k ohms to 2 meg ohms Failure would be open circuit Replace the plug in H2S sens...

Page 38: ...nd level Verify use of span gas Humidifying Tube Check validity of span gas using H2S pull tube or other means check MFG date on cal cylinder Check for obstructions through stainless steel flame arres...

Page 39: ...ith no Faults displayed and the 4 20 mA signal output is 0mA Check that wiring is properly connected at terminal blocks and through to controller inputs The 4 20mA output loop must be closed to avoid...

Page 40: ...ustomerservice oldhamgas com technical support support oldhamgas com repair activities r2 oldhamgas com All Technical Service and Repair activities should be handled by the Oldham Service Department v...

Page 41: ...A Over range condition Serial Output RS 485 Modbus RTU 9600 BPS 9600 N 8 1 Half Duplex Status Indicators 4 digit LED Display with gas concentration full script menu prompts for AutoSpan Set up Options...

Page 42: ...10 w stainless steel j box Electrical Specifications Input Voltage 11 30 VDC Power Consumption Normal operation 68mA 1 7 watt Maximum 85mA 2 watts Inrush current 1 0A 24V RFI EMI Protection Complies w...

Page 43: ...ET 960 240010 000 Desiccant Protection Packet for Cell 6322420 OLCT 710 ceiling mount Calibration Accessories DET 943 000000 000 Calibration Wind Guard DET 943 000006 132 Threaded Calibration Adapter...

Page 44: ...OLCT 700 710 TP Page 38 of 45 Rev C 1 OLCT 700 710 TP Instruction Manual 7 3 OLCT 700710 TP Drawings...

Page 45: ...OLCT 700 710 TP OLCT 700 710 TP Instruction Manual Rev C 1 Page 39 of 45 OLCT 710 TP Series Dimensional Ground Ground...

Page 46: ...OLCT 700 710 TP Page 40 of 45 Rev C 1 OLCT 700 710 TP Instruction Manual...

Page 47: ...OLCT 700 710 TP OLCT 700 710 TP Instruction Manual Rev C 1 Page 41 of 45 8 EU Declaration of conformity...

Page 48: ...OLCT 700 710 TP Page 42 of 45 Rev C 1 OLCT 700 710 TP Instruction Manual...

Page 49: ...sion Date dd mm yyyy Changes made Approval A 0 30 09 2014 Release MS B 0 18 06 2015 Addition of the OLCT 710 MS B 1 29 09 2015 EC Declaration Update MS B 2 01 03 2016 Removal of NPT entry types MS C 0...

Page 50: ...OLCT 700 710 TP Page 44 of 45 Rev C 1 OLCT 700 710 TP Instruction Manual This page has been left blank intentionally...

Page 51: ...OLCT 700 710 TP OLCT 700 710 TP Instruction Manual Rev C 1 Page 45 of 45 This page has been left blank intentionally...

Page 52: ...62027 Arras Cedex FRANCE Tel 33 0 3 21 60 80 80 Fax 33 0 3 21 60 80 00 Website https gasdetection 3m com contact gasandflamedetection mmm com AMERICAS Tel 1 800 247 72570 Fax 1 281 292 2860 ASIA PACIF...

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