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01 April 2010                                                                                    

 

 

 

 

  

 

Group3 Technology Limited  

2 Charann Place, Avondale, Auckland 1026 
 
P.O. Box 71-111, Rosebank, Auckland 1348, New Zealand. 
 
 
Phone: +64 9 828 3358          Fax: +64 9 828 3357           
email

[email protected]

            

web

www.group3technology.com

 

 
 
 
 
 
 
 
 
 

DTM-133 

 

DIGITAL TESLAMETER

 

with IEEE-488 GPIB Communication 
V1.0

 

 

USER’S MANUAL

 

 

 

Содержание DTM-133

Страница 1: ...ce Avondale Auckland 1026 P O Box 71 111 Rosebank Auckland 1348 New Zealand Phone 64 9 828 3358 Fax 64 9 828 3357 email sales group3technology com web www group3technology com DTM 133 DIGITAL TESLAMETER with IEEE 488 GPIB Communication V1 0 USER S MANUAL ...

Страница 2: ...ts and support documentation We welcome input from our customers soifthereareaspects of theinstrument which you particularly like or which you would liketo see improved please contact your Group3 supplier seeback page for acomplete list orGroup3 directly withyour suggestions to sales group3technology com The Group3 website http www group3technoIogy com contains details of all our products This sit...

Страница 3: ...rd Switch Settings 5 3 5 3 Using the IEEE 488 GPIB Interface 5 4 5 4 Triggered Operation 5 19 LIST OF FIGURES 3 1 Fig 1 Panel Cut out Dimensions 3 4 Fig 2 Power Input Connections for the L Option 4 3 Fig 3 Probe Dimensions 5 2 Fig 4 IEEE 4888 Standard Connector 5 2 Fig 5 Location of IEEE 488 Board Switches 5 5 Fig 6 A Typical IEEEE 488 System LIST OF TABLES Table 1 Internal DIP Switch Functions 3 ...

Страница 4: ...Contents 2 DTM 133 User s Manual ...

Страница 5: ... is calibrated with field characteristics stored in memory chip contained in cable plug Accuracy is better than 0 03 for the complete system probe and instrument Temperature coefficient is better than 100ppm C for the overall system Accuracy is verified against nuclear magnetic resonance NMR standard Probe calibration is verified at many field points on every probe and a printed calibration table ...

Страница 6: ... ASCII control commands are accepted to modify the output data format to change the rate of data transmission or to request transmission of a single field reading Other commands select the field range select and peak hold functions turn on and off digital filtering and modify the filter characteristics System status may be determined remotely The system can be operated in triggered mode where fiel...

Страница 7: ...ration 100 ppm of reading C max add 3ppm C for each meter of probe cable zero drift 8 microtesla 0 0015 of full scale C max Temperature stability DTM 133 with MPT 132 probe calibration 100 ppm of reading C typical 140 ppm of reading C max add 3ppm C for each meter of probe cable zero drift 15 microtesla 0 0010 of full scale C typical 40 microtesla 0 0015 of full scale C max Time stability 0 1 max ...

Страница 8: ...decade On board switches digital filtering on off units tesla or gauss Memory backup user entered data stored indefinitely in non volatile memory Power source DTM 133 DTM 133 _S DTM 133 _G ac min 8V 0 65 0 75 1 1 A rms Max 15V 0 3 0 35 0 5 A rms dc min 10V 0 45 0 5 0 75 A dc Max 19V 0 17 0 2 0 3 A dc because a switchmode regulator is used input current falls as the voltage rises ac line input plug...

Страница 9: ...ine feed numerical and system status data requested by commands messages Serial bit rate 16 standard rates switch selected 50 110 134 5 1 TO 200 300 600 900 1050 1200 1800 2000 2400 4800 9600 19200 baud Fiber optic cable Hewlett Packard HFBR 3500 60 meters max IEEE 488 functions SH1 source handshake capability AH1 acceptor handshake capability T5 talker basic talker serial poll talk only mode unad...

Страница 10: ...cable LPT 130 standard sensitivity LPT 230 high sensitivity MPT 132 probes MPT 230 probes Single range probes add range suffix 03 06 12 30 Special probe cable lengths add length suffix XMor XS forXsubstitutecablelengthinmeters 30max M denotes unshielded cable Sdenotesshieldedcable Example LPT 130 2S Accessories fiber optic cable fitted with connectors 60 meter length maximum probe holders fiber op...

Страница 11: ...rring to these features All other aspects of operation are identical Before using your teslameter for the first time please read through sections 3 2 3 3 4 1 4 2 and 4 3 of this manual This will give a quick introduction to basic operation of the instrument 3 2 INSTALLING THE PANEL MOUNT OPTION Model DTM 133 P is supplied fitted with a special front bezel which has threaded studs to allow panel mo...

Страница 12: ...eated flexing of this section Keep the cable out of the way of foot traffic Do not pinch the cable or drop sharp or heavy objects on it A severed cable cannot be re joined without altering the probe s performance and requires factory repair and re calibration The DTM 133 must be used with a Group3 Hall probe Probe models LPT 130 LPT 230 MPT 132 or MPT 230 are the most suitable for use with the DTM...

Страница 13: ...ly and the Group3 ferrite kit part no 11000036 is recommended These accessories will greatly reduce the amount of electrical transient energy entering the teslameter The ferrite kit includes a suppressor which fits to the probe cable near the point of entry to the teslameter to reduce the effects of transients picked up on the probe cable For a full discussion of techniques to promote trouble free...

Страница 14: ...sequently the fuse opens the transformer must be replaced with the genuine Group3 part Fig 2 Power Input Connections of the L option If desired the wiring may be protected by installing an external fuse in the ac power feed Suggested fuse ratings are 200 mA for 115 volts or 100 mA for 208 and 230 volt operation When the unit is first powered up the display shows Group 3 for 2 seconds before field ...

Страница 15: ...ion is indicated by the output voltage polarity There is a small zero offset 10 millivolts maximum arising from the probe zero field output and amplifier offsets The output impedance is 1000 ohm with a 1 nF capacitor to common for noise filtering The cable connector required is a Molex receptacle type M5051 2 fitted with M2759 terminals Pin assignments are given below The analog output is not corr...

Страница 16: ...tered by precision instruments Therefore the teslameter has been carefully engineered to be as immune as possible to sparks and other forms of interference through the use of several kinds of power input filtering and a special high isolation switch mode power module built into its circuitry The design has been verified by extensive testing using high energy sparking in close proximity to both the...

Страница 17: ...viding noise free communication in hostile applications The fiber optic cables used with the DTM 133 are economical and convenient to use simpler in fact than wiring To interface the fiber optic cables to your computer or other data acquisition system use a Group3 model FTR fiber optic adaptor Grounding The Teslameter Case The probe shield is terminated to the probe connector case which is then co...

Страница 18: ...abling through a ferrite tube for a few turns to suppress induced noise The probe cable itself can be passed through a ferrite core The internal diameter will need to be sufficient to pass the probe head through An MPT miniature probe head is nearly the same size as shielded cable 6 5mm diameter but an LPT probe head needs an internal ferrite diameter of 14mm or more Alternatively a split core fer...

Страница 19: ...ification The zero field reading is affected slightly by the presence of metal against the probe s back surface If the probe is to be used clamped to a metal surface or in a probe holder it should be zeroed in the same situation Allow the probe to stabilize thermally for a minute or two before zeroing Ambient temperature also has a slight effect on the probe zero The probe should be zeroed at a te...

Страница 20: ...covers the whole of the ceramic surface Donotapply more force than is required to hold the probe inplace Any strain onthe ceramic will alter the probe s calibration and excessive force will destroy the Hallelement inside Whentheprobeheadismounted thecableshouldbeclamped firmly nearby soit cannotbetornawayfromtheprobeheadif accidentallypulled Theflexiblesection adjacent to theprobehead can becarefu...

Страница 21: ...otating the probe As the probe turns and the measured field rises and falls its maximum value is held on the display See section 4 4 2b LPT 130 and LPT 230 MPT 132 and MPT 230 4 3 READING THE FIELD VALUE The field value is read directly off the display A negative sign indicates that the field direction is opposite to that described in section 4 2 The DTM 133 has autoranging capability and powers u...

Страница 22: ...AY MODES USING THE FRONT PANEL KEYS 4 4 1 The Keys Two front panel keys are used to control the teslameter The MODE key used on its own switches the instrument between its operating modes field and peak hold field and auto ranging Pressing the MODE key brings up the operating modes in the following sequence field display auto ranging power up default mode peak hold field manual range change peak h...

Страница 23: ...s the display shows the true field value A minus sign is added to indicate reverse polarity fields Press the keys together to zero the display The display shows ZEro In auto range all ranges are zeroed in turn taking 10 seconds Field reading is filtered if selected by the internal switch see section 3 5 The FILTER indicator shows when filtering is enabled b Peak hold display ranges as above Displa...

Страница 24: ...ceeded If a single range probe is in use no range changing can occur Overflow The message o FLo is displayed if the computed value of the field reading exceeds the capacity of the display In overflow the instrument is not over ranged but rather the computed reading is too large to be displayed However if over ranging occurs at the same time as overflow then the over range message is displayed pref...

Страница 25: ...g ofconstant or slowly varyingfields Thedefault window widthis20resolution increments oneach sideofthedisplayed field reading for a total window width of 40 increments The digital filter performs the following computation F new F old F F old where F old istheprevious fieldreadingdisplay F new istheupdatedfieldreadingdisplay Fisthemostrecentunfiltered fieldreading J is the filterfactor The effectiv...

Страница 26: ......

Страница 27: ...le 3 is a listing of the pin assignments pin symbol description 1 DIO1 Data Input Output line 1 2 DIO2 Data input Output line 2 3 DIO3 Data Input Output line 3 4 DIO4 Data Input Output line 4 5 EOI End Or Identify 6 DAV Data Valid 7 NRFD Not Ready For Data 8 NDAC Not Data Accepted 9 IFC Interface Clear 10 SRQ Service Request 11 ATN Attention 12 SHIELD Cable shield connects to teslameter case 13 DI...

Страница 28: ...Fig 4 IEEE 488 Standard Connector Fig 5 Location of IEEE 488 Board Switches 5 2 DTM 133 User s Manual ...

Страница 29: ...dds 4 to address set device address adds 0 to address adds 8 to address set device address adds 0 to address adds16 to address dual primary addressing disable enable talker only mode talker listener talker only not used S2 1 S2 2 S2 3 S2 4 S2 5 service requests EOI operation select terminator doubIe terminator not used disabled enabled EOI not asserted EOI asserted line feed carriage return disabl...

Страница 30: ...DTM 133 User s Manual 5 3 ...

Страница 31: ...h is ON carriage return is used S2 4 when ON introduces a pre terminator character before the final string terminator selected by S2 3 The pre terminator is the character not selected by S2 3 The terminator sequence as selected by S2 3 and S2 4 is shown in Table 5 below Table S String Terminator Switch Settings Check which terminator characters are required by the system controller and or other de...

Страница 32: ...Fig 6 A Typical IEEE 488 System DTM 133 User s Manual 5 5 ...

Страница 33: ...nd asserts the DAV line As each listener on the bus accepts and reads the data it removes its assertion of the NDAC line Thus the NDAC line stays asserted until the slowest unit on the bus has accepted the data and releases the line Now the talker can take the data off the bus which becomes available for the next transaction There can be only one System Controller on the bus However the System Con...

Страница 34: ...h are to receive the command Then the command itself is sent to be received only by the devices addressed to listen Command messages are sent on the data bus using 7 bit ASCII codes and are distinguished from data messages by the state of the ATN line ATN is asserted for commands Command messages tall into four groups as shown in Table G below The groups are the Primary Command Group the Listen Ad...

Страница 35: ...3F UNL Unlisten TAG Talk Address Group 64 94 40 5E Talk Addresses 0 through 30 95 5F underscore UNT Untalk 96 126 60 7E SCG Secondary Command Group Secondary Commands 0 through 30 96 111 60 6F o PPE Parallel Poll Enable SCO thru SC15 112 70 p PPD Parallel Poll Disable SP16 127 7F DEL ignored Table 6 IEEE 488 Command Codes For example a device whose address is decimal 18 has a talk address of decim...

Страница 36: ...on from the controller The controller responds by servicing the device in an appropriate way Often the service request is used to indicate that the device has data ready to be sent The controller is not obliged to respond to the service request but the device will hold the line asserted until it has been serviced Service Requests Often IEEE 488 compatible devices have the ability to generate a ser...

Страница 37: ...ich of the 8 data lines the device will use to send its status and bit 4 is used to determine the logic sense of the status For example if bits 1 through 4 were all 0 the device would place 0 on data line 1 during a parallel poll if its status response were in the affirmative 4 the Unlisten command is sent Now if the controller executes a parallel poll by asserting the ATN and EOI lines simultaneo...

Страница 38: ...dard 488 1978 5 3 2 DTM 133 _G IEEE 488 Capability Th e IEEE 488 Standard defines ten interface functions some with as m any as 28 allowable subsets The DTM 133 G teslameters support the interface functions as listed below See also Appendix C of the IEEE 488 1978 Standard SH1 source handshake capability AH1 accept or handshake capability T5 talker basic talker serial poll talk only mode unaddresse...

Страница 39: ... character IEEE 488 mnemonic description 4 04 EOT SDC Selected Device Clear 5 05 ENO PPC Parallel Poll Configure 8 08 BS GET Group Execute Trigger 20 14 DC4 DCL Device Clear 21 15 NAK PPU Parallel Poll Unconfigure 24 18 CAN SPE Serial Poll Enable 25 19 EN SPD Serial Port Disable 32 62 20 3E sp Listen addresses 0 through 30 63 3F UNL Unlisten 64 94 40 5E Talk Addresses 0 through 30 95 SF underscore...

Страница 40: ...7 characters maximum Cancel text mode return to normal display Turns OFF digital filtering Turns ON digital filtering Erase reset peak hold field value Erase zero cancels zero correction on current range Field reading requests a field reading from the teslameter General function Continuous teslameter measures continuously at 30 readings per second This is the power up default mode General function...

Страница 41: ...r field readings Turns On units symbol sent after field readings Set zero enters zero offset n for the selected range useful when the teslameter must be zeroed but using Z command is inconvenient the correct zero offset must be known can be obtained after Z command by using lz and should be noted for future use with SZ Units field values displayed and transmitted in gauss Default set by S2 Units f...

Страница 42: ...ll is performed on a device in this case a teslameter for two reasons to check on its status by decoding the byte output in response to the serial poll and to reset the SRQ line In systems employing interrupts SRQ function is enabled the serial poll will usually be performed after a parallel poll has indicated which device issued the SRQ Performing the serial poll will immediately reset the SRQ li...

Страница 43: ... sent after field readings Units field values displayed and transmitted in gauss Default set by S2 Units field values displayed and transmitted in tesla Default set by S2 FIELD VALUES F Field teslameter returns a field value P Peak hold field teslameter returns peak field value Peak value is always available irrespective of display mode WA Returns uncalibrated raw field reading immediately after d...

Страница 44: ...28 Entered values from 2 to 128 are rounded to nearest allowed value Filtering becomes more severe as n increases Inspect filter factor returns filter factor Window enters n window within which digital filtering occurs Maximum n 255 Default 20 resolution increments on current range Inspect window returns value of window within which filtering operates PEAK HOLD MODE P Peak hold field teslameter re...

Страница 45: ...f the two DIP switches on the main board and the 16 DIP switches on the communications board 0 OFF 1 ON once the command has been given changing theswitchposition does not alterthebaudrateuntil some other command is sent CTRL U Restarts operating software as if DTM had been freshly powered up CTRL X Load system defaults all default values modes reinstated The message RESET is transmitted End of Ta...

Страница 46: ... Alternatively if theteslameter is setfor continuous transmission withthe SM1command after being set fortriggered operation then following V or GET the device will issue a service request if service request is enabled The device can then be parallel polled and the field value read without needing the controller to send the F command As a useful diagnostic aid while a system is being set up the eff...

Страница 47: ...hile in triggered mode If the teslameter is zeroed either with the keys or by remote command while in the triggered mode a new zero offset will be calculated and stored using the last field measurement made The effect of the zero operation will be reflected in the next field measurement when the trigger command is given To ensure themost accurate zero itisbest toplace theteslameter in continuous m...

Страница 48: ...eturned to the Company s factory or any authorized distributor or service center provided thatprior written authorization for suchreturn has been given by the Company This warranty shall not apply to any equipment which the Company determines to have become defective owing to mishandling improper installation alteration negligence inadequatemaintenance incorrectuse exposure to environmental condit...

Страница 49: ...1130 Saint Germain de la Coudre France Ph 33 1 64 49 63 50 Contact Geoffrey Morelle Email g morelle schaefer tech com http www schaefer tec com Germany Schaefer Technologies GmbH Robert Bosch Straße 31 63225 Langen Germany Ph 49 6103 30098 0 Contact Martin Schaefer Email m schaefer schaefer tec com www schaefer tec com India Transact India Corporation B 406 Naman Midtown Senapati Bapat Marg Elphin...

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