Service - Test Equipment Depot
Contents
1. 1 6 1 63 IMC MACS 1 6 ITE Scu RT mS 1 7 1 7 1 RT 1 7 1 72 OVERVIEW Of TIME Controls 1 7 1 7 3 Overview of the Display Indicators 1 7 1 7 4 Overview of the Control Functions 1 8 1 2 5 MENU SEND ee 1 9 1 76 Language Menu siehe 1 12 5 4 ea ee ee 1 13 1 84 Ze1r0 Gallbralonzan ee AN 1 13 1 82 1 14 1 8 3 Linearity 1 15 1 8 4 5 Linearity nenne 1 16 1 8 3 Galibratioh 1 17 1 8 6 Geographical Adjustment 1 17 1 9 R9232 Interface Gudea u 1 18 1 9 1 Setting Communications 1 18 1 9 2 Interface GOMMANGS 1 19 1 3 3 OulpurFormat ae een 1 20 1 10 Cegal For Trade Een 1 21 CHAPTER 2 TROUBLESHOOTING 2 1 eine T 2 1 NETT 2 1 23 Diagnos Gudo 2 A 2 2 2 2 1 05828454 2 2 CHAPTER 3 MAINTENAN2. Load cQ OS n Load amp Zero Format Multiple Single Line Feed Feed 4 Line Feed Form Feed NO LIST YES 21 2 5 Off ff On Off On Off On Off On Off On Off On Off On ff On END END N PRNT 1 Y N PRNT 2 Y Table 1 4 T71 MENU STRUCTURE Part 2 YES RESET NO STABLE OFF ONLY 2 on Pr L niena T CALIBRATE 7EVEN 7000 PARITY 7205 8NoP ie 7 7ODD PARITY 7 8NoP READOUT STOP Relay Output Stable OFF FUNCTION ON XONXOFF 55 HARDWARE seg fee OFF 99 PRINT 1 5 AT ow ep RI 5 M b b PRINT ar TAR ENTER OFF OR ALPHANUMERIC ENTRY ENTER OFF OR END ALPHANUMERIC Off ENTRY 7 Single Line Feed Feed 4 Line Feed Form Feed LOCK MENU NO LIST Bi N Y YES Net 1 1 END LOCK KEY N 8 5 2 Off Off Off Off Off Off Off Off olo 5 5 END 2 END I O Y Layout Notes 1 Hidden when LFT is ON 2 Locked at current setting when LFT is ON 8 Hidden when Dual Scale is OFF CHAPTER 1 GETTING STARTED 1 7 6 Language M
3. APPENDIX A GEOGRAPHICAL ADJUSTMENT VALUES TABLE 1 GEOGRAPHICAL ADJUSTMENT VALUES Elevation above sea level meters Geographical 0 325 650 975 1300 1625 1950 2275 2600 2925 3250 latitude away 325 650 975 1300 1625 1950 2275 2600 2925 3250 3575 from the 1 equator North evation above sea level in feet or South in degrees and 0 1060 2130 3200 4260 5330 6400 7460 8530 9600 10660 minutes 1060 2130 3200 4260 5330 6400 7460 8530 9600 10660 11730 23 22 22 21 21 20 20 19 19 18 18 55552 57904 57 904 58017 98 17 59 32 59 32 60 49 60 49 62909 62 09 63 30 63 30 64755 64 55 66724 66 924 67797 67 57 69 35 69 35 71 21 71 21 73 16 73 16 75524 75 4 77552 77952 80 56 80 56 85 945 8545 90900 8 0 2 5 2 5 8 8 P N 80252588 SERVICE MANUAL 7000 SERIES T71 INDICATORS Test Equipment Depot 800 517 8431 99 Washington Street Melrose MA 02176 TestEquipmentDepot com
4. 1 3 1 3 Printed Circuit Board PCB T71 1 5 1 4 Load Cell Terminal Blocks J4 Scale 1 and J7 Scale 2 1 5 1 5 Load Cell wiring eee 1 6 1 6 CODen shorted UMP ee 1 6 1 7 Reus 5 1 MM T 1 6 1 8 BAUEN BO 1 7 1 9 171 rein T 1 7 1 10 ISOLA Oele 1 7 1 11 Changing the menu language 1 12 1 12 TAP O D 1 16 1 13 ic ev lt gt NEED TT Tm 1 16 1 14 Wire Seal ee ee een 1 16 1 15 TY ATA Leo lee ee een 1 16 2 1 Visual Checking Procedures 2 1 5 1 Series 7000 T71P Indicator Housing amp Internal Parts 5 2 5 1 Series 7000 T71XW Indicator Housing amp Internal Parts 5 4 CHAPTER 1 GETTING STARTED 1 4 INTRODUCTION This service manual contains the information needed to perform routine maintenance and service on the Ohaus 71 Indicators The contents of this manual are contained in five chapters Chapter 1 Getting Started Contains information regarding service facilities tools and test equipment specifications hardware setup or disassembly operating the Indicator scale setup and calibration and configuring
5. 2 Alternate command characters may be defined by the user Data output by the Indicator is always terminated with a carriage return line feed CRLF CHAPTER 1 GETTING STARTED 1 9 3 Output Format The Result Data is output in the following format TABLE 1 6 DEFAULT SERIAL OUTPUT FORMAT Field Label Space Weight Space Unit Space Stability Space G N Space Term Characters Length lt 11 lt 1 9 lt 1 5 1 lt 1 lt 1 ga 0 Notes 1 In certain cases a Label field of up to 11 characters is included 2 Each field is followed by a single delimiting space ASCII 32 3 The Weight field is nine right justified characters If the value is negative the character is located at the immediate left of the most significant digit 4 The Unit field contains the unit of measure abbreviation up to five characters 5 The Stability field contains the character if the weight reading is not stable The Stability field and the following Space field are omitted if the weight reading is stable 6 The G N field contains the net or gross indication For net weights the field contains NET For gross weights the field contains nothing or depending on the GROSS INDICATOR menu setting 7 The Termination Characters field contains CRLF Four CRLF or Form Feed ASCII 12 depending on the LINE FEED menu setting For more information see the Instruction Manual CHAPTER 1 GETTING STARTED 1 1
6. press No and enter the desired value using the keypad Then press Yes To change the calibration unit of measure press No to alternate between kg and Ib Place the specified full load calibration weight on the scale and press Yes The display shows C followed by the 1 2 load calibration point Place the specified 1 2 load calibration weight on the scale and press Yes The display shows C followed by the zero calibration point mall 5 ERN Zal With no load on the scale press Yes The display shows C then DONE and returns to the current application mode CHAPTER 1 GETTING STARTED 1 8 4 5 point Linearity Calibration Use this calibration method to adjust the zero calibration point 1 4 1 2 3 4 and full load calibration points Go to the Calibration menu and Press No until 5 PT LINEAR appears With no load on the scale press Yes The display shows the current full load calibration point and calibration unit of measure Note To change the full load calibration point press No and enter the desired value using the keypad Then press Yes To change the calibration unit of measure press No to alternate between kg and Ib Place the specified full load calibration weight on the scale and press Yes The display shows C followed by the 3 4 load calibration point Place the specified 3 4 load calibration weight on the scale and press Yes The display shows C followed by the 1 2 load cali
7. Yes Allows entry into the displayed menu Accepts the displayed setting and advances to the next menu item No Skips by the displayed menu Rejects the displayed setting or menu item and advances to the next available item Back Moves backwards through the upper and middle level menus Backs out of a list of selectable items to the previous middle level menu Exit Exits from menu directly to the active weighing mode CHAPTER 1 GETTING STARTED 1 7 5 Menu Setup full cap SPAN2 1 3 Acap LINEARITY1 0 LINEARITY2 1 3 CAL TEST1 Table 1 4 T71 MENU STRUCTURE Part 1 YES RESET NO DUAL ON SCALE OFF RANGE1 SINGLE 2 DUAL RANGE2 SINGLE 248 DUAL CAPACITY1 2 SELECT CAP AND UNIT CAPACITY2 2 3 SELECT CAP AND UNIT GRAD1 2 GRAD2 2 3 2 AUTO EF TARE ON 2 ACCEPT ACCUMU OFF LATE 2 ON RETAIN OFF ZERO 2 ON OFF LFT ON BEEPER So VOLUME 7 UNDER SIGNAL OVER UND OVR ET PTIMIZE 2 ON PERCENT OFF POUNDS ON OUNCES 2 OFF MANUAL SEMI AUTO ort LEVEL SECONDS ON VEHICLE OFF Gross INDICATOR Brutto Notes 1 Hidden when LFT is ON 2 Locked at current setting when LFT is ON 3 Hidden when Dual Scale is OFF CHAPTER 1 GETTING STARTED 1 7 5 Menu Setup YES RESET NO STABLE OFF ONLY 2 Par ear Continuous
8. in gravity To determine the GEO factor that corresponds to your location see Appendix A Note Changing the GEO Factor alters the calibration The GEO value was set at the factory and should only be changed if the location of use varies from the default setting To adjust the GEO Factor go to the Calibration menu and Press No until CAL GEO appears Press Yes The default GEO setting appears Press No to increment the number or Back to decrement until the desired number appears Then press Yes Settings from 1 to 31 are available CAL GEO appears again Press No to exit the GEO menu Then press Exit to return to the current application mode CHAPTER 1 GETTING STARTED 1 9 RS232 INTERFACE CONNECTION The T71 has a bi directional RS232 interface for communication with printers and computers When the Indicator is connected to a printer or Programmable Logic Controller PLC displayed data can be output various ways depending on PRINT menu settings For hardware setup of the RS232 Interface see Section 1 5 2 page 1 6 191 Setting Communications Parameters 1 Note Only the COM1 menu appears unless the COM2 interface is set up The T71 Indicator s default communication parameters are baud rate 9600 bits per second bps 8 databits no parity Handshake XON XOFF Address Off Alt Command for Print Off Alt Tare Off and Alt Zero Off To change these settings use the COM1 menu as follows 1 Press and hold TARE Menu
9. the Display PCB Component parts of the Display PCB are not stocked by Ohaus Replacement is recommended rather than repairing 1 2 Separate the and Bottom Housing Follow steps 1 Section 3 2 1 the T71XW remove the Main PCB Follow steps 4 8 in Section 3 2 1 Remove the four screws holding the Display PCB to the Top Housing Carefully lift out the Display PCB to avoid stretching the fine plastic ribbon cable connected to the Membrane Switch Gently remove the two ribbon cables one connected to the Membrane Switch and the other to the Main PCB Avoid bending the pins Connect the ribbon cables to the replacement Display PCB and position the board over the screw holes Insert the screws and tighten them Carefully re position the Main PCB over its screw holes in the Top Cover Re insert and tighten the screws Reconnect the cables removed in Steps 4 and 5 of Section 3 2 1 On the T71P re insert the hex screws connecting the RS232 Interface port to the Bottom Housing 10 Close the Housing and re insert the four screws 11 Perform calibration procedures See Section 1 8 12 Perform testing procedures See Chapter 4 CHAPTER 3 MAINTENANCE PROCEDURES 3 2 3 Membrane Switch Replacement 1 2 Separate the and Bottom Housing Follow steps 1 3 Section 3 2 1 On the T71XW when removing the old Membrane Switch be sure to extract the plastic ribbon cable th
10. the Indicators communication and Legal for Trade menus Chapter 2 Troubleshooting Contains a diagnosis diagnostics chart and error code table Chapter 3 Maintenance Procedures Contains preventive maintenance procedures and disassembly repair and replacement procedures Chapter 4 Testing Contains an operational test segment display test performance tests and adjustments Chapter 5 Drawings and Parts Lists Contains exploded views of T71 Indicators identifying all serviceable components Before servicing the indicator you should be familiar with the Instruction Manual which is packed with every indicator 1 2 SERVICE FACILITIES To service an indicator the service area should meet the following requirements Must be protected from electrostatic discharge e Should be temperature controlled and meet the indicator specifications for temperature environmental requirements See specifications for temperature range Must be free of vibrations such as fork lift trucks close by large motors Must be free of air currents or drafts from air conditioning heating ducts openwindows people walking by fans etc e Area must be clean and air must not contain excessive dust particles e Work surface must be stable and level e Work surface must not be exposed to direct sunlight or radiating heat sources CHAPTER 1 GETTING STARTED 1 3 TOOLS AND TEST EQUIPMENT REQUIRED In order to properly service
11. through modes Menu Yes No Back Exit Function Accepts the Advances to the Moves back Exits the User Short current menu or next menu or to previous menu menu Press setting menu item item Aborts a Rejects the Decrements the calibration in current setting value progress on the display and advances to the next available setting Increments the value Library Yes No Back Exit Function Accepts the Advances to the Moves back Exits the library Short current setting next library or to previous library Press setting or setting Increments the Decrements the displayed value displayed value 1 7 4 CHAPTER 1 GETTING STARTED OVERVIEW OF THE CONTROL FUNCTIONS TABLE 1 3 FUNCTIONS OF DISPLAY KEYPAD Primary 2ABC through 9WXYZ Function Enter 1 Enter alphanumeric values on the Enter Enter 0 on Clear the Short the display display using the multi tap text entry decimal the display last Press method point character space or from the dash on the display display Secondary 1s2 Info Function Change Show the Change the Long display Accumulation polarity of Press between Statistics on the 1 7 5 Scale 1 and the display displayed Scale 2 value Menu Setup To enter the Menu Mode press and hold the TARE Menu button until MENU appears on the display The first upper level menu appears on the display Use Yes No Back and Exit to navigate in Menu Mode
12. until LFT OFF flashes and CALIBRATION appears Press No until COM1 appears Press Yes RESEt appears Press No unless you want to restore the factory defaults COM 1 bAUd appears Press Yes 3 The default Baud rate setting 9600 bps appears To change the setting press No The menu cycles to the next setting each time you press No first 9600 then 300 600 1200 2400 4800 and 9600 again Press Yes when the desired setting appears COM 1 bAUd appears again Press No 4 COM 1 PAritY appears Press Yes The default Parity setting 8 NONE appears To change the setting press No The menu cycles to the next setting each time you press No first 7 Even then 7 Odd 7 None and 8 None again Press Yes to accept a setting PAritY appears again Press No 5 COM 1 StOP BIT appears Press Yes The default Stop Bit setting 1 appears To change the setting press No The menu toggles to the next setting each time you press No first 1 then 2 then 1 again Press Yes when the desired setting appears COM 1 StOP BIT appears again Press No 6 COM 1 HANdSHAKE appears Press Yes The default setting NONE appears To change the setting press No The menu toggles to the next setting each time you press No first XON XOFF then HARDWARE then NONE again Press Yes to accept a setting Then menu moves to the next item 7 COM 1 ALT COMMAND appears Press Yes to set a different command character for the P Print T Tare and Z Zero comm
13. which is at a different temperature than the area where it is to be operated 3 1 1 Preventive Maintenance Checklist The Indicator should be inspected and checked regularly as follows 1 Unplug the AC Adapter before cleaning 2 For the T71P clean the outside using a cloth dampened with a mild detergent 3 For the T71XW use appropriate cleaning solutions for the stainless steel Indicator housing and rinse with water Dry thoroughly CAUTION DO NOT USE CHEMICAL CLEANERS OR SOLVENTS OF ANY TYPE SOME CLEANERS ARE ABRASIVE AND MAY AFFECT THE SCALE S FINISH 4 Check the Power Cord for broken or damaged insulation 5 Make a visual inspection for faulty connectors wiring and loose hardware 3 2 REPLACEMENT OF MAJOR COMPONENTS The decision to replace any component should only be made after thoroughly diagnosing the problem If after the replacement of any component the Indicator is still non functional and no other information on the subject is available in the manual contact Ohaus Corporation by visiting www ohaus com the United States call Ohaus Aftermarket toll free 800 526 0659 between 8 00 a m and 4 00 p m EST CHAPTER 3 MAINTENANCE PROCEDURES 3 2 1 Main Printed Circuit Board PCB Replacement Repairs are not recommended on the Main PCB Component parts of the Main PCB are not stocked by Ohaus Replacement is recommended rather than repairing 1 2 3 10 11 12 13 14 Unplug the Indicator fr
14. 0 LEGAL FOR TRADE LFT NOTE When is set to ON through the LFT sub menu and the Security Switch on the Main PCB is set to ON see Figure 1 1 page 1 2 the following menu settings cannot be changed Span Calibration Linearity Calibration Calibration Unit GEO LFT Capacity Graduation Zero Range Stable Range AZT Modes and Units To enable editing of these menu settings open the Indicator and put the Security Switch on the Main PCB in the OFF position Then set the LFT menu item to OFF as follows 1 Press and hold TARE Menu until MENU LFT OFF appears briefly followed by MENU CALIBRATION Press No 2 S E t U P appears Press Yes Then press No until LFt appears Press Yes OFF appears Press Yes LFt appears again Press No Then press Exit to return to the current application mode 5 It is now possible to use the abovementioned menus After the Security Switch has been turned off before it can be used a trade approved application it must be inspected in accordance with local weights and measures regulations The weights and measures official may apply a wire or paper security seal as shown below Figure 1 13 T71P Paper Seal Figure 1 15 T71XW Paper Seal Figure 1 14 T71XW Wire Seal CHAPTER 1 GETTING STARTED CHAPTER 2 TROUBLESHOOTING 2 1 INTRODUCTION This section of the manual covers visual inspection of the Indicator troubleshooting and a Diagnostic Guide Table 2 1 For s
15. 650 975 1300 1625 1950 2275 2600 2925 3250 3575 from the ERE 113 equator North evation above sea level in feet or South in degrees and 0 1060 2130 3200 4260 5330 6400 7460 8530 9600 10660 minutes 1060 2130 3200 4260 5330 6400 7460 8530 9600 10660 11730 5 4 4 3 3 2 2 0 00 5 46 5 46 952 9552 12944 12944 15906 15906 17910 17 10 19502 19902 2045 20 45 22 22 22 22 23964 2354 25 21 2921 26945 2645 28906 28 06 29 25 29 25 30 41 30 41 31 996 3156 33909 3309 34 21 34721 35 31 35 31 36 41 36 41 87950 37550 38 58 38 58 40 05 40 05 41 12 41 12 42 19 42 19 43726 43 26 44 32 44932 45 38 45 38 46 5 46 45 47951 47951 48 58 48 58 50 06 50 0 51 713 51 13 52 22 52 22 53 31 53 31 54 41 94 41 55752 c 0 NOOO CI c DODO A c N 0 8 c NND Pr C 0 0 CO OO BW CO c N 01 c 0 0 N 0 0 c 006
16. ARTED 1 6 2 Jumper Connections When a 4 wire load cell is attached to terminal block J4 jumpers W1 and W2 must be shorted When a 6 wire load cell is attached to terminal block J4 jumpers W1 and W2 must be open When a 4 wire load cell is attached to terminal block J7 jumpers W3 and W4 must be shorted When a 6 wire load cell is attached to terminal block J7 jumpers W3 and W4 must be removed Bin Connection 1 Excitation 2 Sense 3 Signal 4 GND 5 Signal xd SENS GND SENS er OPEN JUMPERS SHORTED JUMPER 7 Excitation Figure 1 5 Load Cell wiring Figure 1 6 Open shorted jumpers 1 6 3 RS232 Interface The T71P has a built in RS232 Interface a standard 9 pin D style female connector on the back of the T71P Housing In addition each model T71P and T71XW has an optional COM2 connector which can be either RS232 or RS422 485 The optional interface is available separately with its own instructional manual for installation and configuration The RS232 pin configuration for the T71P is illustrated in Figure 1 7 below Pin Connection N C TXD RXD N C GND N C CTS RTS N C 5 4 2 CO 9 8 7 6 Figure 1 7 RS232 Pins oo For software setup of the RS232 Interface through the Indicator s menu see Section 1 9 All other aspects of hardware configuration and setup are described in the Instruction Manual CHAPTER 1 GETTING
17. CE PROCEDURES Sel Preventive 3 1 3 1 1 Preventive Maintenance 3 1 3 2 Replacement of Major Components 3 1 3 2 1 Main Printed Circuit Board PCB 3 2 3 2 1 Display Printed Circuit Board PCB 3 3 3 2 3 Membrane Switch Replacement sees 3 4 CHAPTER 4 TESTING 4 1 MEET mI 4 1 43 Performance Tests Using a Scale 4 1 CHAPTER 4 TESTING continued Page No 4 3 1 Increasing Decreasing Load 4 2 45 2 Overoad Underload TSt Ua 4 2 4 4 Performance Tests Using a Load Cell 5 4 3 45 Calibration Retention Test ssessseseemm 4 3 4 6 RS232 Interface 4 3 A 4 3 CHAPTER 5 PARTS LISTS 8 DIAG
18. D REPLACE BOTTOM COVER a BOTTOM COVER VISUAL CHECKS EXTERNAL amp CRACKED REPLACE ASSEMBLE AND TEST INTERNAL MAIN PC BOARD MAIN PC BOARD RS232 CONNECTOR REPLACE PINS BROKEN RS232 CONNECTOR LCD DISPLAY PARTIALLY LIT OR M BLACKENED VERIFY IF TOP REPLACE PANEL SWITCHES SUBSTITUTE PANEL OR MAIN PC TOP PANEL OR NON FUNCTIONAL TOP COVER BOARD 15 BAD MAIN PC BOARD Figure 2 1 Visual Checking Procedures CHAPTER 2 TROUBLESHOOTING 2 3 DIAGNOSTIC GUIDE Table 2 1 is a Diagnostic Guide designed to help locate the problem area quickly and easily The probable causes are listed with the most common cause first If the first remedy does not fix the problem proceed to the next remedy Before attempting any repairs read all chapters of this manual to be familiar with overall operation and all components 2 2 1 1 Diagnosis Isolate and identify the symptom Refer to Table 2 1 Diagnostic Guide and locate the symptom Follow the suggested remedies in the order they appear Perform the indicated checks or see the appropriate section of the manual Repair or replace the defective part NOTE If more than one symptom is observed approach one area at a time and remember that the symptoms may be interrelated If a problem arises that is not covered in this manual contact Ohaus Corporation for further information 2 2 1 Diagnosis CHAPTER 2 TROUBLESHOOTING TABLE 2 1 DIAGNOSTIC GUIDE Unit will not turn on Power cor
19. Display PCB Replace Main PCB Set selected menu to Off in the Lock Menu Lockout Switch on the circuit board may need to be set to the Off position See Figure 1 1 Replace real time clock battery See Figure 1 3 CHAPTER 2 TROUBLESHOOTING Error 8 1 Weight reading exceeds Power Remove load from scale Recalibrate On Zero limit scale Error 8 2 Weight reading below Power On Add load to scale Zero limit Recalibrate scale Error 8 3 Weight reading exceeds Reduce load on scale Overload limit Error 8 4 Weight reading below Underload load to scale limit scale Error 8 6 Weight value exceeds six digits Use more appropriate unit of measure Reduce load on scale displayed Busy message Displayed during If this message persists it usually tare setting zero setting printing indicates the reading is not stable Correct the instability NO displayed The action is not allowed Do not attempt this operation CHAPTER 3 MAINTENANCE PROCEDURES 3 1 PREVENTIVE MAINTENANCE Ohaus Indicators are precision instruments and should be carefully handled stored in a clean dry dust free area and cleaned periodically Follow these precautionary steps When an Indicator has had chemicals or liquids spilled on it all exterior surfaces should be cleaned as soon as possible with warm water on a damp cloth Allow at least 10 minutes for the Indicator to stabilize after moving it from an area
20. ION Press No until MENU MENU LOCK appears Press Yes L MENU RESET appears Press No L MENU LOCK CAL appears Press Yes L CAL OFF flashes Press Yes Then Press Exit to return to weighing mode Open the Indicator and put the Security Switch on the Main PCB in the OFF position 5 Allow the Indicator to warm up for approximately five minutes after stabilizing to room temperature 6 To abort calibration press the Exit button anytime during the calibration process 18 1 Zero Calibration Zero calibration uses one calibration point The zero calibration point is established with no weight on the scale Use this calibration method to adjust for a different pre load without affecting the span or linearity calibration Press and hold TARE Menu until LFT OFF flashes and CALIBRATION appears Press Yes CAL ZERO appears Press Yes Note If DUAL SCALE is OFF the ZERO SPAN 3PTLIN 5PTLIN menu items are displayed DUAL SCALE is ON the ZERO1 ZERO2 SPAN1 5 2 3PTLIN1 3PTLIN2 5PTLIN1 5PTLIN2 menu items are displayed With no load on the scale press Yes to set the new zero point The display shows ZERO C then ZERO DONE and returns to the current application mode CHAPTER 1 GETTING STARTED 1 8 2 Span Calibration Use this calibration method to adjust the zero calibration point and span calibration point without affecting the linearity calibration Be sure there is no load on the scale Press and hold TARE
21. Menu until LFT OFF flashes and CALIBRATION appears Press Yes CAL ZERO appears Press No CAL SPAN appears Press Yes SPAN and the current unit of measure and Span calibration point flash Note change the span calibration point press No and enter the value using the keypad Then press Yes To change the calibration unit of measure press No to alternate between kg and Ib Place the specified calibration weight on the scale and press Yes The display shows SPAN C followed by SPAN DONE SPAN 0 appears With no load on the scale press Yes The display shows SPAN C followed by SPAN DONE and returns to the current application mode CHAPTER 1 GETTING STARTED 1 8 3 3 point Linearity Calibration This calibration method uses three points The full calibration point is established with a weight on the scale The mid calibration point is established with a weight equal to half of the full calibration weight on the scale The zero calibration point is established with no weight on the scale The mid calibration points cannot be altered by the user during the calibration procedure Press and hold TARE Menu until LFT OFF flashes and CALIBRATION appears Press Yes CAL ZERO appears Press No CAL SPAN appears Press No 3 PT LINEAR appears With no load on the scale press Yes The display shows the current full load calibration point and calibration unit of measure 4L Note To change the full load calibration point
22. RAMS 5 1 7000 Series T71P Indicator Housing amp Internal Parts 5 2 5 2 7000 Series T71XW Indicator Housing amp Internal Parts 5 4 APPENDIX A SETUP amp CALIBRATION VALUES Appendix A Geographical Adjustment Values eese A 1 LIST OF TABLES TABLE NO TITLE Page No 1 1 PECE IONS 1 3 1 2 Functions of Display un nei 1 7 1 3 Functions of Display 1 8 1 4 171 MENU SI US ee 1 9 1 5 Interlace Command 16 1 18 1 6 Default Serial 1 19 2 1 UNG Eee ee 2 3 4 1 Increasing Decreasing Load 4 2 5 1 T71P Indicator Housing amp Internal Parts 5 9 5 2 T71XW Indicator Housing amp Internal 5 5 A 1 Geographical Adjustment Values cccccccccceceeeeceeeseeeeeeeeeeeceeseeeeeeeseeeeeeeseaeeeees A 1 LIST OF ILLUSTRATIONS FIGURE NO TITLE 1 1 and Bottom Housing and Rear Panel 71 1 2 1 2 and Bottom Housing and Rear Panel 71
23. STARTED 1 7 OPERATION This section contains information on the basic operation of the Indicator An exploded view drawing is included in Chapter 5 which identifies all components of the indicator The descriptions in this manual refer to the names of the components identified in the exploded view drawing with the numbered callout 1 7 1 Power Supply Both models have an Internal Universal Power Supply 100 240 VAC 50 60 Hz For the T71XW connect the power cord to a properly grounded electrical outlet For the T71P connect the AC power cord to the power receptacle on the rear of the Bottom Housing then connect the AC plug to an electrical outlet The T71P indicator can also be operated on six alkaline 0 5 charged batteries not supplied when AC power is not available It will automatically switch to battery operation if there is power 25 charged failure or the power cord is removed The indicator can ia 26 50 charged operate for up to 80 hours on battery power nmm 51 75 charged During battery operation the battery charge symbol indicates 76 100 charged the battery status The indicator will automatically turn off when the batteries fully discharged Figure 1 8 Battery charge symbol 1 7 2 OVERVIEW OF THE CONTROLS Capacity label Under Accept amp ne ais nn Over LEDs 7000 Series 5 H C CHCHCHCH GU Jis NESE Keypad 7 segment 6 di
24. Test Equipment 99 Washington Street Depot Melrose MA 02176 Phone 781 665 1400 1 800 517 8431 Toll Free 1 800 517 8431 OHAUS SERVICE MANUAL 7000 Series T71 Indicators 7 SERVICE MANUAL 7000 Series T71 Indicators T71P amp T71XW The information contained in this manual is believed to be accurate at the time of publication but Ohaus Corporation assumes no liability arising from the use or misuse of this material Reproduction of this material is strictly prohibited Material in this manual is subject to change Copyright 2008 Ohaus Corporation all rights reserved TM Registered trademark of Ohaus Corporation CHAPTER 1 GETTING STARTED Page No 4 0 0 01262010 6 EE 1 1 142 gt E 1 1 1 3 Tools and Test Equipment 1 2 1 3 1 Special Tools and Test Equipment List eese 1 2 1 3 2 Standard Tools and Test Equipment 1 2 1 4 T71P and T71XW Top and Bottom Housing 1 2 MS 1 4 16 Hardware Setup or Disassembly 1 5 1 6 1 Connecting the Scale Base s Load Cell 1 5 1 5 2 44
25. ands Otherwise press No Then press Yes when COM 1 END COM appears At this point if a second communication interface is present the COM2 menu is available Otherwise press Exit to return to current application mode CHAPTER 1 GETTING STARTED 1 9 2 Interface Commands The RS232 Interface enables a computer to be used to control some functions of the Indicator using the commands listed in Table 1 4 Command ON OFF IP 72 T xT PU xU PV H x text Esc R Notes TABLE 1 5 SERIAL INTERFACE COMMAND TABLE Function Turns the indicator on Turns the indicator off Immediate Print of displayed weight stable or unstable Print stable displayed weight according to stability setting Continuous Print Print when stable Interval Print x Print Interval 1 3600 sec Same as pressing Zero button Same as pressing Tare button Download Tare value in grams positive values only Sending OT clears tare if allowed Print current unit g kg Ib oz 10 02 Set scale to unit x 129 2 kg 3 4 02 5 10 02 Version print name software revision and LFT ON if LFT is set ON Enter Header line where x line number 1 to 5 text header text up to 24 alohanumeric characters Global reset All menu settings are reset to the original factory defaults 1 Commands sent to the Indicator must be terminated with a carriage return CR or carriage return line feed CRLF
26. at connects to the PCB s Keypad Connector Remove the protective backing from the back of the new Membrane Switch carefully position it on the Top Cover starting at the bottom of the cover Use a rolling motion to smooth the Membrane Switch into position Carefully re position the Main PCB over its screw holes in the Top Cover Re insert and tighten the screws Reconnect the cables removed in Steps 4 and 5 of Section 3 2 1 On the T71P re insert the hex screws connecting the RS232 Interface port to the Bottom Housing Close the Housing and re insert the four screws Perform calibration procedures See Section 1 8 Perform testing procedures See Chapter 4 CHAPTER 4 TESTING 4 1 TESTING Before and after servicing the Indicator operational and performance tests should be made to determine if it meets specifications Turn the Indicator ON and allow it to warm up for at least ten minutes before performing these checks The masses used for calibration should be ASTM Class 4 or OIML Class F2 tolerance or better NOTE Make sure the test area is free from drafts and that the base rests on a level and vibration free surface The masses used for final calibration must be adjusted to ASTM Class 4 or OIML Class F2 tolerance or better 4 2 Power Test The purpose of this test is to determine if the electronic circuitry of the Indicator is functioning properly or not at all In some cases the AC Adapter or line cord supplied wi
27. bration point Place the specified 1 2 load calibration weight on the scale and press Yes The display shows C followed by the 1 4 load calibration point Place the specified 1 4 load calibration weight on the scale and press Yes The display shows C followed by the zero calibration point With no load on the scale press Yes The display shows C then DONE and returns to the current application mode aad CI ro am wwe mul 221 5 Zal CHAPTER 1 GETTING STARTED 1 8 5 Calibration Test NOTE Calibration Test is always available even when LFT is set to ON Calibration test is used to compare a known calibration weight against the stored span calibration data Go to the Calibration menu and Press No until CAL CAL TEST appears With no load on the scale press Yes The display shows the zero load calibration point ee kg With no load on the scale press Yes The display shows T followed by the full load calibration point Place the specified full load calibration weight on the scale and press Yes The display shows 7 followed by difference between the calibration weight and the stored calibration data After five seconds the display returns to the current application mode 1 8 5 Geographical Adjustment Factor The Geographical Adjustment Factor GEO is used to compensate for variations
28. d not plugged in or properly connected Power outlet not supplying electricity Battery discharged Other failure Check power cord connections Make sure power cord is plugged in properly into the power outlet Check power source Replace disposable batteries or recharge NiMH Pack Check cable connections replace Battery symbol blank Battery discharged Replace disposable batteries 5h or recharge NiMH Pack Load on Scale exceeds allowable limits Load on Scale is not stable Load Cell damage Cannot zero the Scale or will not zero when turned on Remove load on Scale Wait for load to become stable Replace Load Cell Poor accuracy Improper calibration Perform calibration Unstable environment Move scale to suitable location Unstable environment Incorrect calibration mass Lock Calibration Menu set to On LFT menu set to On Main PCB failure Unable to calibrate Cannot display Unit not set to On weight in desired weighing unit Problems with Display missing characters partial display erratic or unstable display Display PCB failure Menu has been locked Cannot change menu settings Does not retain correct time Real time clock battery failure Move the scale to suitable location Use correct calibration mass Set Lock Calibration Menu to Off Set LFT menu to Off Replace Main PCB Enable unit in the Units Menu Check Display PCB Cable Replace
29. enu Setup The T71 menus are available in English Spanish German French and Italian To change the menu language press and hold TARE Menu until MENU appears When the button is released the Legal For Trade status is displayed followed by the first menu To navigate the menus press No to move to the next menu or Back to move to the previous one Press Yes to enter the displayed menu Press Exit to immediately leave a menu and return to weighing mode The map below shows the steps to enter the Language menu and choose Espanol Figure 1 11 Changing the menu language CHAPTER 1 GETTING STARTED 1 8 CALIBRATION Four calibration processes are available Zero Span 3 point Linearity and 5 point Linearity Calibration In addition a Calibration Test and Geographical Adjustment Factor setting are accessible from the CAL menu Preliminary Steps 1 sure appropriate calibration masses are available before beginning calibration 2 sure the scale base is level and stable during the entire calibration process If LFT is set to On calibration is unavailable To set LFT to OFF see Section 1 10 page 1 19 Note To use the LFT mode again after turning it off it is necessary to have the Indicator locked and sealed by local Weights and Measures authorities 4 If the Calibration Menu is locked in the Menu Lock submenu turn it back on Press and hold TARE Menu until MENU LFT OFF appears briefly followed by MENU CALIBRAT
30. es 7000 T71P Indicator Housing amp Internal Parts CHAPTER 5 PARTS LISTS amp DIAGRAMS 5 1 7000 SERIES T71P INDICATOR HOUSING amp INTERNAL PARTS TABLE 5 1 71 INDICATOR HOUSING amp INTERNAL PARTS e eres C OoOo o AC Relay Kit Accessory Main PCB CHAPTER 5 PARTS LISTS 8 DIAGRAMS 5 2 7000 SERIES T71XW INDICATOR HOUSING amp INTERNAL PARTS 20 qo 22 15 U NO 2 amp amp E Figure 5 1 Series 7000 T71XW Indicator Housing amp Internal Parts CHAPTER 5 PARTS LISTS amp DIAGRAMS 5 1 7000 SERIES T71XW INDICATOR HOUSING amp INTERNAL PARTS TABLE 5 1 T71XW INDICATOR HOUSING amp INTERNAL PARTS 1 Capacity Label Kit Membrane Switch Membrane swen _ 0 Wall Mount Kit PCB Power Supply Cable Kit 14 15 16 19 20 21 22 23 23 4 Knob Kit Set of 2 Accessory 5232 Interface Kit Accessory AC Relay Kit Main PCB 2 CHAPTER 5 PARTS LISTS 8 DIAGRAMS APPENDIX GEOGRAPHICAL ADJUSTMENT VALUES APPENDIX A GEOGRAPHICAL ADJUSTMENT VALUES TABLE 1 GEOGRAPHICAL ADJUSTMENT VALUES Elevation above sea level in meters Geographical 0 325 650 975 1300 1625 1950 2275 2600 2925 3250 latitude away 325
31. etup and connection to either a known good base or simulator see Chapter 1 Follow all directions step by step Make certain that the work area is clean and use care when handling components of the Indicator 2 2 VISUAL INSPECTION Carefully remove the Indicator from its packing container and remove any packing material fastened to the unit Note all items supplied with the unit such as AC power supply cables instruction manual weights etc Keep a record of all items and note their condition 1 Examine the Indicator for signs of abuse such as a cracked top cover or base damage from liquids cracks on corners which may suggest the unit was dropped 2 Open the Indicator by removing the four screws in the rear housing Be careful not to stretch the cables that connect the main Printed Circuit Board PCB to the outlets RS232 and Load Cell ports and power supply 3 Examine the top of the main PCB for cracks or signs of corrosion 4 If it appears that corrosion may have affected the board and you want to examine the bottom of the PCB remove the four screws holding it to the housing 5 Carefully lift out the main PC board If it is cracked or shows signs of corrosion it requires replacement See Chapter 3 Maintenance Procedures for board replacement and testing If the Indicator shows no sign of physical damage continue with procedures see chart below for visual checking procedures CRACKED REPLACE TOP COVER TOP COVER CRACKE
32. ghing Parts Counting Checkweighing Percent Weighing Vehicle Weighing Display 25 mm 1 in High 2 line LCD Over Accept Under Indicators Red Green Yellow LED Ingress Protection Load Excitation Voltage Load Cell Input Sensitivity Auto Zero Tracking Off 0 5 1 or 3 divisions Zeroing Range 2 or 100 of capacity Span Calibration 1 kg or 1 Ib to 100 capacity Overall Dimensions 10 3 x 3 0 x 5 8 W x D x H in mm 260 x 71 x 168 262 x 76 x 149 Net Weight Ib kg 7718 5 Shipping Weight Ib kg 9 5 4 3 Operating Temperature Range 10 to 40 C 14 F to 104 F Main Power 100 240 VAC 50 60 Hz Internal Universal Power Supply 6 C type LR14 Batteries Rechargeable battery pack Battery Power option Rechargeable battery pack option Can be either RS232 or RS422 485 CHAPTER 1 GETTING STARTED 1 6 HARDWARE SETUP OR DISASSEMBLY Both the T71P and T71XW connect to a scale base through a Load Cell Cable that connects to the Indicators Main Printed Circuit Board PCB CAUTION ELECTRICAL SHOCK HAZARD REMOVE ALL POWER CONNECTIONS THE INDICATOR BEFORE SERVICING OR MAKING INTERNAL CONNECTIONS The process of opening the Housing varies slightly for each model T71P T71XW 1 Remove the four Phillips head screws 1 Remove the four hex head screws from from the rear housing the rear housing 2 Open the housing disconnect the 2 Open the housing by carefully pulling ribbon cab
33. git J LI LI l We LED display Control Buttons Figure 1 9 T71 Display 1 7 3 OVERVIEW OF THE DISPLAY INDICATORS Scale symbol 1 2 4 Range symbol ik 4 Kilogram Gram es Percent Pound Ounce Net symbol eme no 1 1 1 0 Negative 1 Fy Stable weight TT Li 1 tt i S Pieces symbols indicator o au ow 1 4 NA MA INVE MALIA Preset Tare VAN WANN AM Brutto Gross charge Memory symbols 14 segment Figure 1 10 T71 Display Indicator ph symbol display symbol Tonne CHAPTER 1 GETTING STARTED 1 7 4 OVERVIEW OF THE CONTROL FUNCTIONS TABLE 1 2 FUNCTIONS OF DISPLAY CONTROLS DE Yes Back Exit Primary ON ZERO PRINT FUNCTION TARE LIBRARY Function Turns the Sends the Initiates an Performs a tare Display the library Short Indicator on current value to application mode operation data Press If Indicator is the COM port if Temporarily on sets zero AUTOPRINT is displays the set to Off active mode s reference data Secondary Off Units Mode Menu Edit Function Turns the Changes the Allows changing Enter the User Enable editing Long Indicator off weighing unit the application menu the current library Press mode record Press and hold allows scrolling
34. le from the top of the PCB the top of the front housing forward Figure 1 2 shows T71 s Main PCB with connectors jumpers terminals and switches indicated Scale 1 Load Cell Power Supply Terminal Block J4 COM2 Connector N Scale 2 Load Real Time RY N Sede 1 Sense PEWS Terminal Jumper W4 RS422 485 Clock Battery Jumper a J7 Battery Rechargeable connector Battery T71P only if p p x me UM Ut 43 T71P opposite side DE O PCB Connection Security Switch RS232 Terminal J7 Scale 1 Load Cell External Inpu T71XW only Scale 1 Sense Connector J14 Terminal Block J9 RS232 Connector Jumper W1 T71P only T71P only Figure 1 3 Printed Circuit Board T71 Indicator 1 6 1 Connecting the Scale Base s Load Cell The T71P has a circular connector jack on its Bottom Housing The white plastic six wire plug connects to the Scale 1 Load Cell Connector J14 See Figure 1 3 Attach a base without a circular connector to one of the Load Cell Terminal Blocks on the Main PCB Pass the load cell cable through a Cable Gland see Figure 1 1 and attach it to Terminal Block J4 or Terminal Block J7 See Figure 1 4 Tighten the Cable Gland to secure the cable and maintain a tight seal Jumper connections must be shorted or opened as follows UP 220 Figure 1 4 Load Cell Terminal Blocks J4 Scale 1 J7 Scale 2 CHAPTER 1 GETTING ST
35. om the AC power source Remove the four screws from the Bottom Housing Carefully separate the Top Housing and Bottom Housing on the T71P disconnect the Display PCB s ribbon cable from the top of the Main PCB Pull all cable connectors from their plugs on the Main PCB including on the T71XW the Display PCB s ribbon cable from the Main PCB If cable leads are connected to the Scale 2 Load Cell Connector J7 see Figure 1 1 loosen the terminal block s set screws and remove the leads On the T71P remove the hex screws connecting the 5232 Interface port to the Bottom Housing so the port will clear when the PCB is lifted out Remove the four screws from the PCB and on the T71XW a fifth securing the grounding cable to the PCB on the lower left CAUTION When handling the PCB grasp it by the edges only Do not touch the foil side Static discharge may damage some components Lift out the PCB Carefully re position the replacement PCB over the screw holes in the Top Cover Re insert and tighten the screws Reconnect the cables removed in Steps 4 and 5 On the T71P re insert the hex screws connecting the RS232 Interface port to the Bottom Housing Close the Housing and re insert the four screws Perform calibration procedures See Section 1 8 Perform testing procedures See Chapter 4 CHAPTER 3 MAINTENANCE PROCEDURES 3 2 2 Display Printed Circuit Board PCB Replacement Repairs are not recommended on
36. or 2 Place a mass on the scale base platform which slightly exceeds the capacity of the scale base and observe the Indicator display The display should indicate Error 8 1 Remove the mass from the scale base The display should return to zero 4 4 Performance Tests Using a Load Cell Simulator A simulator can be used in place of a scale base if available Connect the simulator to Terminal Block 94 the Load Cell terminal block on the PCB so that EX EX S4 and S are matched at each end of the cable See Figures 1 1 and 1 2 page 1 4 Setthe Jumper connections as explained in Section 1 6 1 and 1 6 2 Test the Indicator as follows 1 Set the simulator to zero Power on the Indicator Perform a Span Calibration with zero at the simulator s zero setting and 10096 capacity at the simulator s 2 0 milli volt setting 2 Following calibration check that the Indicator s display reading is stable at each simulator level up to the maximum set in the calibration If the readings are stable the Indicator is functioning properly 4 5 Calibration Retention Test This test checks that the Indicator retains calibration after power is removed and then restored 1 Turn the Indicator OFF and disconnect the AC Adapter or power cord 2 Wait one minute then reconnect the AC Adapter or power cord to the Indicator 3 Checkto insure that the Indicator retained calibration settings 4 6 RS232 Interface Test Print Test The RS232 In
37. terface performance can be monitored using an external printer or computer connected to the Indicator To set up communication parameters see Section 1 9 1 Once the communications parameters match between the Indicator and either a computer or printer it is possible to test the Indicator s print function Press the Print Units button Printing to an external printer or computer should occur each time the button is pressed CHAPTER 5 PARTS LISTS amp DIAGRAMS This section of the manual contains exploded views for the 7000 Series T71 Indicators The exploded view drawings are designed to identify the parts which can be serviced on the indicator in the field NOTE In all cases where a part is replaced the balance must be thoroughly checked after the replacement is made The balance MUST meet the parameters of all applicable specifications in this manual If further technical information is needed please contact your local Ohaus distributor or Ohaus Corporation www ohaus com 19A Chapin Road P O Box 2033 Pine Brook NJ 07058 2033 USA Tel 973 377 9000 Fax 973 593 0359 In the United States call toll free 800 526 0659 between 8 00 a m and 6 00 p m EST CHAPTER 5 PARTS LISTS 8 DIAGRAMS 5 1 7000 SERIES T71P INDICATOR HOUSING amp INTERNAL PARTS 22448 C 254A III T Figure 5 1 Seri
38. th the Indicator may have become defective 1 Plug the AC Adapter or line cord into a suitable power source 2 With the Indicator connected to an appropriate power supply press the ON ZERO Off button The Indicator performs a self test indicates the software revision and then goes into weighing mode 3 If all of the displays appear normal in this test continue with the next test If the display did not appear check that the AC input is good and that the AC adapter or line cord are functioning properly and repeat the test If the display was erratic the PC board is defective and requires replacement 4 3 Performance Tests Using a Scale Base These tests are performed on the Indicator using a known good scale base and test mass At this point the Indicator has been checked for full display menu setup and calibrated If a Load Cell Simulator is being used proceed to paragraph 4 4 Select the maximum possible resolution 1 20 000 to obtain the most accurate test results CHAPTER 4 TESTING 4 3 1 Overload Underload Test This test determines if the Indicator displays the proper indication when an underload or overload condition exists on the scale base 1 With the Indicator ON and no mass on the scale base lift up on the scale base platform and observe the display The display should indicate Error 8 2 Release the platform The display should return to zero N Note Do not exceed Load Cell capacity when testing the Indicat
39. the Indicator certain special tools and test items are required in addition to standard electronic tool kits These items are listed as follows 1 3 1 Special Tools and Test Equipment List 1 Ohaus Scale Base Load Cell Simulator optional Computer with RS232 Interface RS232 Interface cable Data Printer for use with RS232 communications D Xp ge ESD work station or mat 1 3 2 Standard Tools and Test Equipment List 1 Standard Electronics Tool Kit 2 Digital Voltmeter DVM with clip on probes Input impedance of at least 10 megohms in the 1 Volt dc position 3 Soldering Iron solder and flux remover 1 4 Top and Bottom Housing Adjusting Mounting Security screw Battery DR Compartment Hole plug RS232 for option Connector Figure 1 1 Top and Bottom Housing and Rear Panel T71P CHAPTER 1 GETTING STARTED 1 4 Top and Bottom Housing Adjusting Knobs m Mounting Bracket eed 4 hex head RS232 RS485 422 Scale 2 Load Cell Relay Option Cable RS232 Cable Security screw 7 Power Cord Figure 1 2 Top and Bottom Housing and Rear Panel T71XW CHAPTER 1 GETTING STARTED 1 5 SPECIFICATIONS TABLE 1 1 SPECIFICATIONS T71P T71XW Maximum Displayed 1 50 000 Resolution Maximum Approved Resolution 1 10 000 Maximum Counting Resolution 1 500 000 Weighing Units Kg g oz 10 02 tonnes custom Functions Static Weighing Dynamic Wei
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