Model 4618B User`s Manual
Contents
1. Assign the primary address wrt H CHR 13 CHR 10 CALL IBFIND N BD Subrtn Call Init Pri Addr CALL IBWRT BD wrt Subrtn Call output data END LLELELLLLLLLLLLLLLLLLLLLLLLLLELLLLLLLLLLLLLLLLLLLLLLL DATA ACQUISITION The 4618B requires no specific input instruction in order to output immediate torque and speed data Simply follow your Computer GPIB interface instructions and issue a data input command If your primary address is set and addressed correctly the 4618B will respond It will probably be necessary to dimension your input variable to 15 13 characters plus CR LF Speed Torque data from the 4618B is in ASCII format and rigidly structured with leading zeros as follows SdddddTdddd L Where d Decimal digit 0 thru 9 S indicating that the following 5 digits are RPM T indicating that the next 4 digits D P is Torque The last character shown L may be either L or R L CCW dynamometer torque application R CW The following is a simple single input instruction source program written in Microsoft Quick Basic using a National Instruments Corp GPIB PCIIA P N 320043 01 IEEE 488 Interface It will access the 4618B fetch immediate data and display it exactly as received dokololetoleloetelejelolejoleleteteletetejotelejeteleleteleteteloetetejetelejeteleleteletetejetelejetek CLS N DEV8 Assign the primary address assume 08 rd2. SPACES 15 Make room for the data CALL IBFIND N BD Subrtn Call Init Pri Addr CALL IBRD BD rd Subrtn Call Input data to rd PRINT rd END 3K K K K K K K K K 3K 2K K 2K K 3K K K 2K K K K 2K K 3K K K 2K K 2K K K 2K K K K K K K K 3K 2K K K K K 2K K K K K K DATA ACQUISITION PROBLEMS Usually a failure to communicate is a result of improper computer input variable word size none or incorrect termination characters CR LF You may save time by contacting Magtrol Customer Service ask for GPIB software assistance 4 Circuit Description TACHOMETER Mounted on the end of the Dynamometer shaft is an encoding disc divided into 60 opaque and clear segments A Lamp Photocell in combination with the disk produces a pulse train of 60 Bits revolution for RPM indication This frequency data 1s applied to a counter where the time base read and reset functions are under control of an MPU The elements comprising the counter and time base shown in the following block diagram are contained on PC Bd TSC 1 QI is the input detector Ula b and c are buffers The basic counter is comprised of elements U8 and U9 The time base is composed of elements U5 U6 and U7 The time base input frequency is 1 0M Hz reduced to a precise 1 2 second period Additionally there are buffers and hand shaking elements U10 and U11 TORQUE TRANSDUCING All Magtrol load cell equipped dynamometers produce an analog torque signal where the
3. located in the upper right corner of the 4618B chassis facing from the front The sketch shows that portion of the board where the trimpots are located and their identification TORQUE ZERO ADJUSTMENT 1 Remove any couplings from the dynamometer shaft 2 Place a precision voltmeter resolving at least 1 millivolt D C between pins 13 and 14 on the DYNAMOMETER ribbon connector pin 13 negative You may have to remove the connector cap on the cable or obtain access from inside the dynamometer rear panel 3 Adjust the dynamometer zero control for best zero dynamometer torque signal output on your voltmeter The object of the following steps is to alternate between the and Q Bal trimpots until you know that each is adjusted such that your output torque reading is just at zero on both trimpots While observing the 4618B Output Torque Reading 1 Adjust the Q Bal trimpot slowly try both CW and CCW rotation until the indicated torque value reads slightly higher then back off very slowly until the reading is zero or returns to the original value Repeat this procedure on the Q Bal trimpot work back and forth and set zero with a 1 flashing occasionally FULL SCALE TORQUE CALIBRATION 1 Complete the zero adjustment procedure outlined in the preceding paragraph Install the Dynamometer Torque Calibration beam as shown in the sketch on the next page 2 Rotate the TORQUE control on your power supply full CW for maximum appl
4. PSB 5 providing 5 logic power 15 Volts for the analog elements If you have questions or require more detailed information please contact Magtrol Customer Service Dept Technical Information 5 Calibration and Balancing There are calibration and offset adjustment controls for most of the analog elements in the 4618B Normally no adjustment of these elements is anticipated for the life of the instrument However all or part of the calibration and balancing procedures may be indicated if any of the following conditions exist Atorque difference between CW and CCW full scale readings of greater than 2 least significant digits in standard resolution Inability to zero the Torque reading with the ZERO control located on the back panel of the dynamometer There is no calibration for the digital speed reading accuracy Please refer to MODEL 4618B SPECIFICATIONS in this chapter PROCEDURE Routine Torque calibration and zero offset adjustments should always be done on the Dynamometer The torque signal offset and calibration controls within the 4618B are there to permit standardization to precise and known value inputs Warning The following requires removal of the 4618B top cover All connections and trimpot adjustments must be made only as specified herein and with caution There is an electrical shock hazard inside the 4618B All calibration and balancing potentiometers are contained on the circuit board identified TSC 1
5. and frequency of adjustment The Torque conversion elements within the 4618B contribute no more than a temperature related drift of up to 005 C_ of ambient change of reading Please refer to your Magtrol Dynamometer User s manual for additional information on Torque accuracy Testing Measurement and Control of Torque Speed Power Load Force Weight Tension Displacement MAGTROL INC 70 Gardenville Parkway Buffalo New York 14224 USA Phone 1 716 668 5555 Fax 1 716 668 8705 E mail magtrol 9 magtrol com MAGTROL SA Route de Moncor 4B 1701 Fribourg Switzerland Phone 41 0 26 407 3000 Fax 41 0 26 407 3001 E mail magtrol 9 magtrol ch Subsidiaries in Germany France Great Britain China Worldwide Network of Sales Agents www magtirol com Certified ISO 9001 2000 by Bi n 150887
6. signal level is exactly equal to the torque value in millivolts For example an HD 400 6 with 43 42 Oz In of torque applied will output a voltage of 0 4342 volts Connector J2 on PC Bd No TSC 1 receives this signal and applies it to operational amplifier U2a and U2b The output of U2b is used by the MPU to establish the CW and CCW appled torque direction indication on the digital readout U2a output is applied to U2c a buffer for the torque signal output applied to the ACCESSORY TORQUE SPEED OUTPUT connector on the rear panel of the 4618B This same signal is also applied to two V F converters U3 and U4 The frequency output is converted to digital using an integration period identical to the speed conversion time This results in concurrent integration of both torque and speed for dynamic tracking accuracy U13 and U14 are the counting elements their outputs buffered by U15 and U16 SIGNAL PROCESSING The primary MPU and GPIB controlling electronic functions are contained on the PC Bd MCI 2 On this assembly U5 is the Microprocessor U9 is the Programmable Read Only Memory containing the 4618B operating system There is a 2K disc emulation RAM device identified as U10 U11 and U12 are Peripheral Interface Adapters U1 U2 and U3 are the GPIB interface control elements U6 and U7 are the LED segmented digital readout drivers The balance of the components are buffer and timing control devices There is a power supply PC Bd
7. M ceto tecto IGI eub ae epo ua Ene eode ar Moneda rado 6 DATA ACQUISMION M 6 DATA ACQUISITION PROBLEMS uscessecitecttetes entes acte tees tesis tbe ee snae ea eed rasta tapete ripa 7 4 iid vsum T 8 TACHOMETER geass acess stenoses osteo saci suctus cata SE deans Eu Op tM Me DE 8 TORQUE TRANSDEGIN I 5 esucerzteeteptebuEtes tisse dci tium bate omae trs auis eese auta 8 SIGNAT PROCESSING us pitasteberee a bh eer in tec Dos Re tenes rebas a c ote deb ss inp papa RSE 8 grupo Emo Es iSESi sa 9 PROCEDURE creerea adag a a a cpi a er 9 DEDI 9 TORQUE ZERO ADIUSTIMEBT ecceerazatos eqs ertet e ene mes ctu eet raid tieu uisi be eta 9 FULL SCALE TORQUE CALIBRATION retener a Ree tet a o ER ERE eodeiona 10 ACCESSORY TORQUE OUTPUT CALIBRATION eee ener 10 MODEL 4618B SPECIFICATIONS 1t react Er esemnha te sprk laneo Lag ERSTER RD E Pop epe petu eus duces 10 PLEASE READ This document includes text recovered from the final edition of a now obsolete manual of a discontinued Magtrol product Magtrol Inc assumes no responsibility for errors or omissions Additionally no liability is assumed for any damages that may result from the use of the information contained within this publication LAST PRINTING EA August 1992 J KAACSTROL 1 Introduction ABBREVIATIONS Please note For the balance of this reference man
8. Magtrol 4618B User s Manual Contents MD me 2 ABBREVIATIONS istuc atu abe a Melee eles Sadie e pte beh oi cMeta es 2 UNPACKING rc ion eao o Ea mcn Ree s Ma MEUS 2 NS RUMAN T POWBR r a e t ette a Ne a a aa ates 2 OPERATIONAL CHECK sinrang oea a a a e a a a 2 2 COSY AGN asin C 3 TORQUE DI OIN a en ere dee REE ene ae Un Or 3 SPEED DISPLAY RR REDE 3 PUSHBUTTON FUNCTIONS erinin aan ORI ERRINDIN ae Un CR D cp oV Qe cu R 3 SIVO xL 3 CN CAT 3 Recall esos os cede snes abese can ences e E vases E E E E E E eceense 3 hoc M EE 4 je p 4 3 Computer Duteriacilip uon aoro sten inas terea ee Eun xS EUER Usu ountous ukas vassa erar S Reo PNE ec HR RSS E NE VAR ER KRESS 5 INSTALLATION peor a E ey uM Eod a a a a Res 5 GPIB IEEE 488 arn a a S a E E a S 5 GPIB Computer Installation 0 ccccccccccccccscesccssecsecssceseeseecsscssecsecssecsesseecsecssecsesssesseessessscsseccsesssessesseeeseeaes 5 Software Installation eod cn o a b de E e eee Et b rae Besnard eta HA eed cede eie 5 PRIMARY ADDRESS 5 4618B INSTRUCTION SET sssccsscissciastecss5etceaseaskasaoavabaccabs ie p
9. ection switch The default setting from the factory on the 4618B is eight 08 If you wish to change the code the chart will help in obtaining the setting you want Please note that the MSB is to the right Switch segment identification resulted in the binary code notation reversed from the standard convention where the LSB is normally on the right Some PC interfaces National GPIB PC2A will access 0 to 16 4 Bit primary address numbers only Others may access up to 31 5 Bit codes even though the GPIB capability is limited to 16 instruments The 4618B Primary Address uses the 5 bit format Before selecting a value greater than 15 check to be sure that your particular interface code range capability is within range of the address you wish to select 4618B INSTRUCTION SET There are two instructions H CR LF will set Hi Resolution operation S CR LF will set Standard Resolution Memory control of the 4618B is not GPIB addressable since the same data is accessible to the computer via the bus Generally the computers memory resources are much more extensive and more readily managed than the 4618B via the bus For your reference the following is a programming example to output a HI RES instruction It is given in Microsoft Quick Basic using a National Instruments Corp GPIB PCHA P N 320043 01 IEEE 488 Interface dokokeletoleloetelejoetelejelolejeteleleteleteteloetetejetelejetelejeteleteteletetejoetelejeteler CLS N DEVS
10. ied torque With a precision weight apply a known torque at or close to full scale in the CCW direction Maintain the beam exactly horizontal and perfectly still 3 Observe the voltage reading on the voltmeter Across Pins 13 and 14 Adjust the TORQUE CALIB on the rear panel of the dynamometer for a vo tmeter millivolt reading exactly equal to the true torque applied 4 Adjust the Q Cal trimpot until the 4618B torque reading is equal to the voltmeter reading and the true torque applied 5 Place the weight on the opposite side of the beam adjust the Q Cal trimpot to match the 4618B Torque reading to the true torque applied ACCESSORY TORQUE OUTPUT CALIBRATION With zero torque on the dynamometer nothing connected to the shaft 1 While reading the 4618B Torque Value adjust the Dynamometer ZERO Control for best zero reading 2 With a voltmeter resolving at least 1 millivolt D C connected between pins 2 and 4 on the ACCESSORY TORQUE SPEED OUTPUT connector adjust trimpot Qo Bal for best zero reading 3 Attach a Calibration beam energize the brake to hold the beam attach a weight to apply an amount of torque close to the dynamometer full scale rated value Adjust Qo Cal for the correct torque reading on the voltmeter MODEL 4618B SPECIFICATIONS Speed Accuracy 0 05 of the SPEED reading 1 0 RPM Torque Basic torque accuracy is controlled by the Dynamometer ZERO and CALIBRATION controls by the level of care
11. l technical information PUSHBUTTON FUNCTIONS Save The first time you press the SAVE button the LED will go on and stay on If you turn the 4618B off then on again the SAVE LED will come on again indicating there is data in memory To lose it you must erase it Each time you press the button data currently displayed is snapshot and appended to memory You have 380 complete display test values before you run out of memory In the unlikely event you should the display will momentarily flash HELP to signal the condition Clear To clear the memory and also minimize accidental erasure the SAVE and RECALL push buttons must be pressed simultaneously If you have nothing in memory worth saving try it you will find that you have to be fairly synchronized when pressing both buttons You will know while pressing the buttons if the memory 1s cleared all three SAVE RESET RECALL LEDs will go ON Recall If the SAVE LED is on when you depress RECALL the SAVE LED goes off the RECALL LED goes ON placing the display in RECALL mode with the first data point saved displayed 3 If you press the RECALL button again the display advances to the next data values saved and so on When you have advanced through all of the contents of memory the last reading will remain unchanged but the RESET LED will flash ON OFF four times indicating you have reached the last item in memory If you press the SAVE LED while in RECALL mode nothing hap
12. nstallation On most computers the GPIB interface is not a standard item An interface card must be installed in the computer and the driver software made resident on disc There are several manufacturers of these products but some systems exchange data more rapidly than others In motor testing usually the test rate and speed of data acquisition is very important One recommendation is National Instruments Corp PN GPIB PC2A for IBM or compatible PCs It will be necessary to install a IEEE 488 Cable between the computer and the 4618B All of this equipment is available from Magtrol along with installation assistance and software help if you require it For additional information contact Magtrol Technical Sales Software Installation There are usually a number of formatting questions to be answered the first time that the GPIB interface control software is installed The following items pertain to the 4618B All GPIB data acquisition systems require the use of data termination characters The 4618B uses the Hewlett Packard HPIB standard termination characters Carriage Return CR Line Feed LF in that order The 4618B looks for these instructions to terminate communication reset the interface and continue with normal program execution PRIMARY ADDRESS All instruments serviced on the GPIB have a separate primary address code On the rear panel next to the GPIB connector there is an opening providing access to the code sel
13. pens except the RESET LED flashes four times in protest It is not logical to save data already saved Reset This is active in RECALL mode only It does two things First the RECALL mode is exited restoring the display to immediate data Second the memory data pointer is reset to the beginning of the data memory stack for future RECALL mode Of course the SAVE LED will go back on because there is still data in momory If no data were in memory you would not have been able to enter the RECALL mode in the first place If you wish to simply kold a single reading freezing the display the memory must be clear Simply tap the SAVE button then RECALL Hi Res This pushbutton operates as a toggling function effecting on y the torque reading When the resolution is less than 1 part in 1000 the decimal point will shift one digit to the left The torque resolution will be increased by a factor of 5 The least significant digit scales by 2 0 2 4 6 8 3 Computer Interfacing INSTALLATION GPIB IEEE 488 Please be sure that the computer and the 4618B are both turned off when you install the GPIB connector cable If you have completed the equipment check out as outlined in Chapter 1 the 4618B Dynamometer interconnection is complete If a Model 4629B controller is used in conjunction with the 4618B Digital Readout the computer interface shoud be connected to the 4629B only Please refer to your 4629B User s Manual GPIB Computer I
14. r shaft by hand You should see both the Torque and Speed displays respond Depress the HI RES Push Button The torque reading decimal point should move one digit to the left o2 If the above checks out satisfactorily it s a pretty good bet that the equipment has survived shipping and is working satisfactorily 2 Operation If the 4618B is used in conjunction with a Magtrol Model 4629B controller please refer to your Dynamometer User s Manual interconnection diagram The Dynamometer should connect directly to the Model 4629B with the 4618B serviced from the 29B with a 7Pin Din 14 Pin Ribbon cable Magtrol P N 88CS09 TORQUE DISPLAY Dynamometer torque is displayed with 4 digits in floating point notation Preceding the MSD is a sign indicating shaft direction The plus sign indicates clockwise torque application minus counter clockwise 5 When you first interconnect the dynamometer before a motor is coupled to the shaft the torque display may not indicate zero Assuming that you have removed the the load cell restraining shipping bolt please proceed with the dynamometer rear panel ZERO and CALIB procedure covered in your Dynamometer User s Manual in Chapter 1 Calibration SPEED DISPLAY Shaft RPM is indicated on 5 digits to the nearest 1 0 RPM The update rate on both the speed and torque display is 0 5 seconds The resolution and basic accuracy of the Speed reading is fixed See Chapter 4 for additiona
15. ual the following terms are used LED refers to the Light Emitting Diode indicators on the push button switches of the 4618B e The term GPIB General Purpose Interface Bus is interchangeable between HPIB and IEEE 488 UNPACKING Your Model 4618B is adequately packaged for shipping We recommend that all cartons and packing material be saved until the unit has been checked operationally If there is any evidence of shipping damage notify the carrier and Magtrol Customer Service as soon as possible Please be sure to sort through the carton and packing material carefully for cord sets and other loose items INSTRUMENT POWER Warning Please check the line voltage setting The Model 4618B operates from either a 120V 60Hz or 240V 50Hz power source If the point of destination line power is 240 50Hz please check that the voltage is set properly Adjustment is made with a switch contained in the line cord receptacle on the rear panel The line cord is a detachable NEMA Standard 3 wire All Magtrol Dynamometer and Electronic Products require that the cabinets and fixturing be earth grounded for proper equipment operation and personnel safety OPERATIONAL CHECK In order to check the 4618B it will be necessary to have a Magtrol Dynamometer a 14 Pin 14 Pin Ribbon Connector Cable This cord set 1s supplied with the dynamometer Please install it before turning on any equipment 1 Turn on the Power Switch left side 2 Spin the dynamomete
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