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DCell & DSC Strain Gauge or Load Cell Embedded

1. 17 Mantracourt Electronics Limited DCell DSC CANopen User Manual Apply the high known test weight and enter the required SYS value for this weight In this case it will be 100 Click Next to continue AX SYS Calibration Auto Result Instrument calibration complete The new calibration values have been calculated and the instrument updated Click Finish to complete this Wizard The display below shows the value of SYS You can now apply the low and high inputs to check that the calibration was successful You can press the Back button to return to a previous calibration stage to repeat it SYS 99 99995 NOTE Some instruments have parameters that clamp the output values If the SYS output seems incorrect you should first check the instrument manual to see if there are any parameters that can clamp this output The device is now calibrated However you may find SYS has been clamped if the resultant SYS is greater than SMAX or less than SMIN If this is the case then change these values to suitable limits In this example we may set SMIN to 0 5 Kg and SMAX to 110 0 Kg This would then provide clamping of SYS to these values and also a flags being set in FLAG and STAT For detailed information about calibration calculations please refer to chapter 3 Mantracourt Electronics Limited DCell amp DSC CANopen User Manual 18 Chapter 3 Explanation of Category Items Instrument Explorer shows the categories to w
2. E Temperature Measurement Accuracy 10 to 85 Temperature Measurement Accuracy 55 to 125 pS AA Ae Temperature update Speed Electrical o o o a Power Supply voltage Power Supply ripple Power Supply current 350R Bridge Environmental Data transmission rate 20K tm bs 1000 m 85 C Output cable length speed dependant Operating temperature range 40 Storage temperature TAHT Humidity TR fe ee AA PCB Dimensions DSC 87 4 x 20 x 8 5mm PCB Dimensions DCell Diameter 20mm Height 10mm Power 10v 350R Bridge Notes 1 From original offset at any time 2 1st Year 3 Dependent on cable type and bit rate The DSC digital output is an open collector transistor rated at 100mA 40v Mantracourt Electronics Limited DCell amp DSC CANopen User Manual Technical Specifications DSC DCell Industrial Stability DSC Conditioner is nominally set for 2 5mV V sensitivity Parameter Min Typical Max Units 4 Wire Strain Gauge Drive Capability 320 500 Ohms Offset Temperature Stability 5 10 ppm C Gain Temperature Stability 30 f 50 ppmc Offset Stability with Time TT 35 160 ppm of FR 1 25 2 Non Linearity before Linearization I 25 p pm of FR Internal Resolution 16Milin Counts divs Resolution 1Hz readings Noise stable over 1008s 66 000 Counts divs Resolution 10Hz readings Noise stable over 100
3. Mantracourt Electronics Limited DCell amp DSC CANopen User Manual Sys Calibration Auto Assume we require to calibrate for Kg output and we have available a known accurate 10 Kg and 100 Kg test weights Start the wizard by selecting Sys Calibration Auto from the Wizard menu SYS Calibration Auto Instructions This Wizard will allow you to calibrate your instrument by applying 4 known low input followed by a known high input You will need two levels of input at around 25 or below of full scale and a high level input at around 75 or higher of full scale You will also need to know the required value of SYS for both of these input levels Press NEXT to continue with the calibration Cancel Click Next Ak SYS Calibration Auto Acquire Low Input Apply the low level input and enter the value required in the text box below Ensure that the low input is still applied when the Next button is clicked Enter required value for SYS at this low input level x Back Next Cancel Apply the low known test weight and enter the required SYS value for this weight In this case it will be 10 as we want the units of SYS to be Kg Click Next to continue Ak SYS Calibration Auto Acquire High Input Apply the high level input and enter the value required in the text box below Ensure that the high input is still applied when the Next button is clicked Enter required value for SYS at this high input level nod
4. The input for the temperature compensation is MVV and the output from the process is CMVV If not temperature compensation is invoked the CMVV is equal to MVV Temperature compensation cannot be used at RATE of 8 200Hz A Detailed explanation is given in chapter 5 Cell Scaling CGAI COFS The temperature compensated value CMVV is scaled with gain and offset using CGAI and COFS respectively The gain is applied first and the offset the subtracted This would be used to give a force output in the chosen units this output being termed CRAW CRAW CMVV X CGAI COFS 21 Mantracourt Electronics Limited DCell DSC CANopen User Manual Two Point Calibration Calculations and Examples Examples are given here for two point calibration as this is by far the most common method Cell Calibration The scaling parameters are CGAI and COFS CGAI is in cell units per mV V COFS is in cell units The cell output calculation is in the absence of temperature and linearity corrections CRAW CMVV x CGAI COFS If we have two electrical output MVV readings for two known force loads we can convert the output to the required range So if test load fA gt CMVV reading cA test load fB gt CMVV reading cB then calculate the following gain value CGAI fB fA cB cA and the offset is COFS cA x CGAI fA The outputs should then be CELL fA fB true force values as required Calibration Methods There
5. cA x SGAI xA 100 0112 x 1 003580x10 0 09988 0 00048924 Check Putting the values back into the equation results for the two test loads should then be For x 99 88Kg CELL 100 0112 so SRAW 100 0112 x 1 003580x10 0 00048924 0 09988 For x 500 07Kg CELL 498 7735 so SRAW 498 7735 x 1 003580x10 0 00048924 0 5006987 The remaining errors are due to rounding the parameters to 7 figures Internal parameter storage is only accurate to about 7 figures so errors of about this size can be expected in practice System Limits SMIN SMAX These are used to indicate that the desired maximum and minimum value of SRAW have been exceeded They are set in weight units On SRAW being greater than the value set in SMAX the SRAWOR flag is set in both FLAG and STAT the value of SRAW is also clamped to this value On SRAW being less than the value set in SMIN the SRAWUR flag is set in both FLAG and STAT the value of SRAW is also clamped to this value Mantracourt Electronics Limited DCell amp DSC CANopen User Manual 24 System Zero SZ SZ provides a means of applying a zero to SYS and SOUT This could be used to generate an Net value making SRAW in effect a gross value SYS SRAW SZ Care should be taken on how often SZ is written to see WARNING Finite Non Volatile Memory Life later in this chapter System Outputs SYS SOUT SYS is considered to be the main output value and it is this value
6. 5 Problems are likely if any calibration MIN MAX parameters are set the wrong side of zero i e MIN gt 0 or MAX lt 0 Problems with Bus Baud Rate There are a number of special difficulties to be considered here e Systems with very long cabling may not work with higher bit rates e Always remember you need to reboot devices before the change takes effect Difficult problems can always be overcome if necessary by isolating individual devices and trying the different bit rates in turn This deals with all possible problems as long as your hardware can deliver all the supported baud rates Recovering a lost DCell DSC Resetting to default ID Due to the configure ability of the devices CAN settings it is important to note all changes made to these settings or you may lose the ability to communicate with the device In particular if the ID is changed from the default it would be very difficult to find the ID by trial and error as there are 2047 possible ID s available on a Can 2 0a 11 bit system and 536 870 911 for Can 2 0b 29 bit identifiers For this reason the DSC has a built in mechanism to reset the base ID back to the default value of 1 To activate this recovery mode the device must be sent 2 commands over the CAN Bus on the broadcast ID of 0 with the second command being sent within 2 seconds of the first It is important that the device to be reset is the only device to be connected on the CAN bus otherwise all devices will be
7. DSC DCell amp DSC Strain Gauge or Load Cell Embedded Digitiser Module CANopen 2 Generation Software Version 3 onwards User Manual www mantracourt co uk FOR ENTERPRISE MC mantracourt Contents Chapter A IMtroducti On toi ii dels o s oaa ea aise AAA RA ii 4 OVERVIEW A 4 Key Features ibi A A A A bs ct 4 Sp cial Facilities ii A daa 5 Version 3 Additions and Enhancements oooooccnccnccnncncconcnncnncnnco nce ne ene eneeneeee ees eee ees eeeeeneeneeeeeeseeseeseeaeeeees 5 The Product RANTE a OS Di a Aa 6 Which Device To Use coin da tati 6 Additional DCell DSC Variants Available ccc sce cce cence eee ec ence nee ee ene ene eee eee eee eeeeeseeneeneeeeeesenseeseeaeeeees 6 Some Application Examples iia a 7 Chapter 2 Getting Started with the Evaluation Kit o oooococcccncccconcnnccnccnccnccnccnconcccccnccccconconcanccnccnnononss 8 The Evaluation Kitii cand odes ccd ve drid ennea ce EET EEVEE A a TAS di ia ada 8 COMO ES ti E O A A A AA AAA 8 Checking the Device TY Pex oia A A A ELESE 9 Connecting Up The Evaluation Kit oseese isi e cence eee eens eens eee eeeeee eee e nese aE EEEE n A aak 9 initial CHECKS scs 550 datas fred cadaen a EE AS ETEA 9 Instrument Explore corrr eee ck hee le tea Mes dada AA A a 9 What Can Instrument Explorer Do ccccceesccesccesnee eee eee eens eens eee ee ease nese eee eeeseeeeeeeeeesaseeeseeeseeeeeesseees 9 Installing Instrument Explora ss Hanada da sed cn Daa
8. SMAX Systemrangemax RW boo __ gt _ gt _p USR1 9 Userstorage values RW 5031h 5039N 0 0 FFLV Dynamic Filter Level RW 503Ch FFST Dynamic filter steps RW 503Dh CTN Number of Temperature Compensation RW 503Eh A AA ee CT1 5 Temperature Compensation Point______RW__ 503Fh 5043h_____ 0 0 __ CTG1 5 e Compensation Gain adjust RW 5044h 5048h 0 CTO1 5 remperature Compensation Offset Adjust RW a 504Dh x PER RST SNAP e aa o ooo RSPT pepe e a G eee SCON SCOF E cal OFF WO DA OPON oe Output On WO OPOFF Digital Output Off wO on fT Table Key Denotes a range e g CLK1 7 means CLK1 to CLK7 Access RW RO WO X read write read only write only execute 47 Mantracourt Electronics Limited DCell DSC CANopen User Manual Chapter 10 Installation This chapter gives detailed information on integrating DCell and DSC devices into a production system including mounting protection adjustments wiring and electrical requirements Before Installation Carefully remove the DCell DSC device from its shipment box Check that the device is complete and undamaged Check the Product Type Code on the product label is that which you ordered The DCell DSC can operate in any industrial environment providing the following limits are not exceeded Operating Temperature 40 C to 85 C Humidity 95 non condensing Storage temperature 40 C to 85 C For precise details of Envir
9. This allows for an offset change to be made easily as the offset is not a component of gain The Product Range Devices are available in two physical formats The DCell puck products consist of a Digital Strain Gauge Signal Conditioner with CAN bus output in double sided component population format This is suitable for installation in very small spaces including load cell pockets External connections are made by wiring to through hole pads Mounting is via a 2mm mounting hole to accept M2 screw or American equivalent 0 80 Important Note DO NOT USE 2 screw size The DSC card products are very similar to the DCell but in a different physical form for mounting stand alone or on a board External connections are via header pins which can plug into connectors or be soldered to wires or into a host PCB DSC has an open collector output and volt free digital input Which Device To Use It is important to select the correct product for your application First choose DCell or DSC based on your physical installation needs Common Features Both physical formats offer identical control and near identical measurement performance Differences Only the DSC card is available with digital Input amp output Special Aspects To Consider The DCell fits neatly into a strain gauge pocket The DSC lends itself to PCB mounting Additional DCell amp DSC Variants Available A separate variant is available with RS232 or RS485 output Re
10. mV V Output In Percentage Terms ELEC ccccccccccsesscesscscesescceedaccceeseccessctessebscseessccsesenssesessecenseaes 19 Temperature Vallie TEMP icc cesseueee reineta be dev E pad coven dees A e a eee tewes ded ala 19 Output Rate Controls RATE soc ge sees Soe is Ses eae a eg By AAS a 19 Dynamic Filtering FEST and FFEV cocci n eaei cdee dada dea eden notado iaa maso decana so andado nda das 20 Collin A E A A A A E Al 21 Temperature Compensation In Brief oooocooccconcconcconcconnconncoonccn nono n cono eene senses neeeeaeeeeeeeeseeeseeeeeeseeens 21 Cell Scaling CGAI COPS aa A A As 21 Two Point Calibration Calculations and Examples cccceccesccecncenceeeeeeneeeeeeenseenseesaeeeeeeeeseeeseeeseeseeens 22 Calibration Methods v s AAA ii 22 Gelli Limits CMN CMAX reisuren reee rasa e eo o nea a A AAA edad 23 Linearisation In Brit A A A A id id 23 SM A A A ts 23 System Sealing SGAL SOES mna srei enet pE EE A AA ARA rada 23 Example of calculations for SGAI and SOFS ssssessssssssssssssssssssssssessssessesssesesesesseeeeecceesocoseoeeeeseesesseees 24 System Limits SMIN SMAX s enes eoe soere elas dense e A PASE EEEa OEE DAA Dd 24 SYSTE ZEO SZ ae n eee A a wa A sagen soem bas NE RRA 25 System Outputs SYS OUT a ds SENEE TEE SERE ETERA ERER 25 Reading Snapshot SNAP SYSN iesss ce rio cra cos ia E E EEEE AE ene oe ne bene ER TSS E A 25 Cotos cass concn OT A Rs 25 Shunt Calibration Commands SCON and SCOF ooo
11. then i n 1 Otherwise i is chosen so that CLXj lt x lt CLXj 4 The resulting interpolated adjustment value is then calculated as ofs CLKj CLKj 4 CLKj x x CLX CLX 4 CLXj Then the compensated cell value is calculated as CELL CRAW ofs Mantracourt Electronics Limited DCell amp DSC CANopen User Manual 36 How to Set Up Linearity Compensation A linearity correction can be set up either from sensor specification calibration data or more commonly from in system testing results Assuming we do not have any prior information on linearity errors the usual approach is to do a series of controlled tests with accurately known test loads Just as with temperature compensation it is possible to obtain a detailed graph of linearity error and then choose a best fit piecewise linear curve for the compensation table However it is generally good enough and much simpler to simply test at several different points and then apply an exact correction at those points If the error curve is reasonably smooth this should give exact results at the test points and reasonably accurate values in between NOTES Linearisation tests should only be done after the cell calibration is set because the correction values are dependent on the cell calibration Similarly linearisation testing should only be done at the calibration reference temperature or after temperature compensation is installed to avoid
12. Access DEVICE TYPE RO 1000h o Unsigned 32 bit ERROR REGISTER RO 1001h Unsigned 8 bit PRE DEFINED ERROR FIELD RO 1003h Unsigned 32 bit COB ID SYNC MESSAGE RO 1005h o Unsigned 32 bit RESTORE ALL PARAMETERS FROM 1000H TO WO A 2001H note 1 RESTORE COMMUNICATIONS PROFILE WO PARAMETERS 1000H TO 1FFFH note 1 NODE ID amp BITRATE note 1 Note 1 should always be 4 bytes value SAVE MSB LSB 65h e 76h y 61h a 73h Mantracourt Electronics Limited DCell amp DSC CANopen User Manual Transmit PDO Operation Specific N Description Access Object Object icti Dictionary Sub Index TPDO 1 transmit 02h i i 255 Use Event timer Type a D D D PDOE1 TPDO 1 Unsigned 16 bit Transmission a PDOT2 TPDO 2 transmit 02h Unsigned 8 bit 255 Use Event timer Type i i W PDOI2 TPDO 2 Inhibit timer RW 3h Unsigned 16 bit 0 Disabled RW PDOE2 TPDO 2 Unsigned 16 bit Transmission eee ism PDOT3 TPDO 3 transmit RW 02h Unsigned 8 bit 255 Use Event timer gee ie eee AAN PD TPDO 3 COBID W 01h Unsigned 32 bit 0 Use default of 0x380 Node ID W z W R PDOI3 TPDO 3 Inhibit timer R Unsigned 16 bit 0 Disabled R PDOE3 TPDO 3 Unsigned 16 bit 100mS eee rise interval PDOT4 TPDO 4 transmit RW 02h Unsigned 8 bit 255 Use Event timer pa AA A ere 4 COBID W 0x80000000 Disabled w i W R PDOI4 TPDO 4 Inhibit timer R 3h Unsigned 16 bit 0 Disabled PDOE4 TPDO 4 R
13. Cele ties ads anual AA ve vations E AA seven ias 51 DSC Strain Gauge Cabling Arrangement ceccececce nce ene cence ence cence ene eenee eee eeee sense eeeeeeeseenseeeeeenseeeeeeeaees 52 Key Requirements ici a E el evade A AAA di 52 Communications Cabling and Grounding Requirements ooocococcnoncconcccnncconcnoncnoncoonnnonnconnononc conc cnanonanono 53 DCell Power and Communications Wiring cece cece eee eee ence ence eeeeeee eens eens eens eeneeeneeeeeseeeeeeeeeenseeeeeeeaees 53 DGellBus End Arrangement csesactes a pia se tcaaedy 53 DSC4 Versions Power and Communications Wiring cceecceecceesceenceeneeeneeeseeeneeeneeeeeeeenseeseeenseenseeeaees 54 DSC4 Versions Bus End ArrangeMent ccccccecceenceenceene eens cence ene AKETE EEEE E Ea i a E 54 Key ROQUIFSMENES ii A A AA laws caus 54 S itable Cable TYPES 2000 A a ad 54 DCell DSC CAN Bus Cable veicoocoosorionnodocon cata se ceve cess condeno aaa dE tada decada cda ved isis 54 CAN Bus Connections for Multiple DCells oooooocconcccnccccncconnconnconcconnccnn coo n cnc roo or conc ron rro nc nora c cnn nonanono 55 CAN Bus Connections for Multiple DSC Versions ccceeccesceenceeneeene cence snes eeeeeeneeenseeneeenseeeeseeeseeeseeseeene 55 Key REquireMents ires roiricstesir out renns iE eae EEANN EVERE E EEEE oe Ii 56 Bus Layout and Termination a A A Ea a E E EE EEE 56 LOAGING e a eee A A daved aeaa a e A de la 56 Strain Gauge Sensitivity Ad
14. ECOM is an un filtered precursor of ELEC CRAWUR and CRAWOR are the cell output range warnings These are tripped when the cell value goes outside programmable limits CMIN or CMAX The tested value CRAW is the cell output prior to linearity compensation SYSUR and SYSOR are the system output range warnings These are triggered if the SYS value goes outside the SMIN or SMAX limits LCINTEG indicates a missing or a problem with the Load cell It is based on the common mode of the SIG being correct NOTE This flag will also be set when the shunt calibration has been switched on WDRST indicates that the Watchdog has caused the device to re boot If this error continually occurs consult factory Mantracourt Electron ics Limited DCell amp DSC CANopen User Manual 26 BRWNOUT indicates that the device has re booted due to the supply voltage falling below 4 1V the minimum spec for supply voltage is 5 6V and this must include any troughs in the AC element of this supply REBOOT is set whenever the DCell DSC is powered up and is normal for a power up condition This flag can be used to warn of power loss to device Dynamic Status Flags STAT Status are live flags indicating current status of the device Some of these flags have the same bit value amp description from FLAG Meaning and Operation of Flags The various bits in the STAT value are as follows Bit Value Description Name Setpoint output sta
15. Gain table point CTN sets the number of points in the gain amp offset table s A CTN value of less than two effectively switches off temperature compensation The maximum number of point is 5 values greater than 5 reset CTN to 0 switching off temperature compensation CT1 to CT5 sets the temperature in degree C of the correction points The table must be filled from CT1 up to amp including CT CTN and must be entered in order of increasing temperature value CTO1 to CTO5 provide the offset adjustment in mV V x10 The reason for the multiplication is due to the limitation set by the ASCII protocol of only being able to enter up to 6 decimal places The CTOx value is subtracted from the uncompensated value CTG1 to CTG5 provide the gain adjustment in ppm terms The actual gain value used is calculated as 1 CTGn x 10 Internal Calculation The temperature compensation calculation is described as follows The GAIN correction is applied first The current measured temperature is checked against the table values CT1 to CT CTN to establish an index value if the measured temperature is below that of CT1 then CT1 is used as the index If the temperature is above CT CTN 1 then CT CTN 1 is used This can be represented as follows A working table index i is derived from the current measured temperature T as follows n number of points used as set by CTN When T lt CT1 then i 1 When T gt CTn 1 then i n 1 Oth
16. Mechanical Specification tor Dal as 62 CEA oe 62 WAIMTANLY ii A A a a ita 63 3 Mantracourt Electronics Limited DCell DSC CANopen User Manual Chapter 1 Introduction This chapter provides an introduction to DCell DSC products describing the product range main features and application possibilities Overview The DCell and DSC products are miniature high precision Strain Gauge Converters converting a strain gauge sensor input to a CANopen output They allow multiple high precision measurements to be made over a low cost 2 wire link Outputs can be accessed directly by PLCs or computers or connected via various types of network all without compromising accuracy The device is configurable using a CANopen configuration tool Key Features Ultra miniature The DCell puck format can be fitted inside most load cell pockets and similar restricted spaces The DSC cards are similarly very small optimised for mounting as a component onto custom PCBs High precision Industrial Version 25ppm basic accuracy equates to 16 bit resolution High precision High Stability 5ppm basic accuracy equates to 18 bit resolution with comparable stability far exceeds standard instrument performance Low power Low voltage DC supply 5 6V min typically 40mA for RS485 and 52mA for RS232 including 350R strain gauge Adjustable sensitivity Configured for standard 2 5mV V full scale strain gauges as supplied A single additional
17. Unsigned 16 bit Transmission interval 1 Each TPDO can have a maximum of two objects mapped 2 PDO Parameters are stored directly to non volatile memory but will not take effect until the device has been re booted or an NMT reset communications has been issued 3 0x80000000 disables the TxPDO otherwise setting a non zero value will result in this value being used instead P P P P me OT1 OC1 TPDO 1 COBID Unsigned 32 bit 0 Use default of 0x180 Node ID See Note 3 Ol TPDO 1 Inhibit timer Unsigned 16 bit 0 Disabled 0C3 un un o D o oO o D o D 3 z 3 z n o n o ot ot D D Ww Ww 45 Mantracourt Electronics Limited DCell DSC CANopen User Manual Transmit PDO Mapping Specific Name Description Access Object Object Data Type Defaults Dictionary Sub Index PDOP1 TPDO 1 Mapping RW 01h See details below 0x50050004 item 1 SYS Sub Index 0 Length of 4 Bytes PDOS1 TPDO 1 Mapping RW See details below 0 Disabled item 2 PDOP2 TPDO 2 Mapping RW See details below 0x50090002 item 1 FLAG Sub Index 0 Length of 2 Bytes item 2 PDOP3 TPDO 3 Mapping RW See details below 0x500D0002 item 1 SYSN Sub Index 0 Length of 4 Bytes PDOS3 TPDO 3 Mapping RW See details below 0 Disabled PDOP4 TPDO 4 Mapping RW See details below 0 Disabled item 2 PDO mapping data entries consist of the following data which are 4 bytes total First Two bytes ar
18. are generally simpler than testing over temperature the accuracy requirement is often greater See below for notes of possible difficulties to be avoided Control Parameters Refer to the table in Chapter 9 for command numbers The lookup table based on parameters CLXi CLKi defines an offset adjustment based on the CRAW value which is then added in to give the final CELL output So linearity correction is applied after any temperature compensation The Parameters Involved Are CLN Sets the number of linearisation points from 2 up to 7 CLX1 7 Raw input CRAW value points CLK1 7 Output CELL adjustments to apply at these points They are used like this e The number of calibration points is set by CLN from 2 up to 7 e Raw input value points are set by CLX1 CLX2 CLX7 or up to the number set by CLN These must be arranged in order of increasing input value e The output corrections at these points are set by CLK1 CLK2 CLK7 e Corrections are specified in thousandths of a cell unit So a CLKi of 1 0 actually adds 0 001 to the CELL output This due to a limitation in the ASCII conversion to floating point numbers Internal Calculation This uses the same basic interpolated table lookup method as for temperature compensation First a working table index i is derived from the current raw input CRAW x as follows n number of points used as set by CLN When x lt CLX1 then i 1 When x gt CLXp 1
19. po 1 unused reserved Unused NONE unused reserved Unused NONE Temperature under ase TEMP 0 3 erp 4200h device temp 4 16 Strain gauge input under range 0 7 mfrspecd o i ee ne paa 6 64 Cellunder range CRAW 0 7 mfr specd N AJN O OT KR WW oo Cell over range CRAW 0 7 mfr specd System under ee SRAW 0 7 mfr spect aia O O NO A ooo 8192 unused reserved 0 7 mfr Ta 16384 Brown Out Reset 0 7 mfr specd T 15 32768 Reboot warning Normal Power up 0 7 mfr specd 6000h device software Communications Controls The units NODE ID is configured over the CAN BUS by writing to the object at index 2000h sub index 0 The Node ID is stored in non volatile memory and changes will not take effect until the unit is power cycled Units are delivered with a CANopen Node ID set to 127 The CANbus Bit Rate can be configured by writing to the object at index 2001h sub index 0 where the following value settings are defined Setting O 1 2 3 4 5 6 7 EE If a value lt 0 or gt 7 is sent to the unit the next time the power is cycled the unit will return to it s default Bit rate of 125 Kbits to avoid loosing communications with the unit by entering an invalid Bit Rate It is Essential that the Bit Rate is set correctly or communications with the device will no longer be possible Again stored in non volatile memory and changes
20. reset to the default Each Command consists of 7 ASCII Bytes as its Data message bytes shown below First Command Byte 1 2 3 4 5 6 7 8 ASCII M A N T R S T Blank DECIMAL 77 65 78 84 82 83 84 Blank HEX 4D 41 4E 54 52 53 54 Blank Second Command must be sent within 2 seconds of First Command Byte 1 2 3 4 5 6 7 8 ASCII D O R E S E T Blank DECIMAL 68 79 82 69 83 69 84 Blank HEX 44 4F 52 45 53 45 54 Blank After sending the command sequence recycle the power to the DSC the DSC will then have the default base ID of 1 59 Mantracourt Electronics Limited DCell DSC CANopen User Manual Chapter 12 Specifications Technical Specifications DSC DCELL High Stability Set for 2 5mV V sensitivity Parameter Min Typical Max Units 4 Wire Strain Gauge Excitation Voltage 4 5 5 5 25 VDC Strain Gauge Drive Capability 320 5000 Ohms Offset Temperature Stability 1 pme Gain Temperature Stability es 3 5 pmc Offset Stability with Time 20 80 I ppmofFR 1 Gain Stability with Time O da ppm of FR 2 Non Linearity before Linearization 5 25 ppmofFR Internal Resolution 16Milin Counts divs 200 000 Counts divs Resolution 10Hz readings Noise stable over 100s eoo __ counts ds Resolution 100Hz readings Noise stable over 100s 50 000 Counts divs Dynamic recursive type user programmable SE
21. resistor configures the input between 0 5 and 100 mV V full scale Temperature sensing and compensation optional An optional temperature sensor module is available and advanced 5 point temperature compensation of measurement Linearity compensation Advanced 7 point linearity compensation CAN Output Lower cost cabling improved noise immunity and longer cable runs with no accuracy penalty Device addressing allows up to 127 devices on a single bus drastically reducing cabling cost and complexity Two way communications allow in situ re calibration multiple outputs and diagnostics No separate measuring instruments needed Digital calibration Completely drift free adjustable in system and or in situ via standard communications link Two independent calibration stages for load cell and system specific adjustments Programmable compensation for non linearity and temperature corrections Calibration data is also transferable between devices for in service replacement Self diagnostics Continuous monitoring for faults such as strain overload over under temperature broken sensors or unexpected power failure All fault warnings are retained on power fail Mantracourt Electronics Limited DCell amp DSC CANopen User Manual Special Facilities Output Capture Synchronisation A single command instructs all devices on a bus to sample their inputs simultaneously for synchronised data capture Output Tare Value An internal co
22. shortcut on your desktop Instrument Explorer Icon 3 Shortcut to Instrumente The application should open and look like the following shield shot Instrument Explorer Window YE Instrument Explorer TER Bile Communications Parameters Watch Logging Wiz rds Macros View Help Mantrabus 1 ADP 15 standard ADW15 standard Sua LCAIS Fa standard yy UABIS al standard MantraASCi 2 E DCell v3 c DSC v3 Mantrabus 2 E ak mmm DSC v3 MantraCAN x DCell v3 Not Logging Not Watching No Errors Mantracourt Electronics Limited DCell amp DSC CANopen User Manual 10 The layout of Instrument Explorers Window and child windows allows the user full customisation to their requirements If the application show a different arrangement of child windows than the above shield shot then using then load one of the default workspaces as follows Click File on the menu and select Open Workspace From the file dialogue window select Layout Standard iew This will ensure your application layout matches this document A list of available instruments is displayed in the Select Instrument pane of Instrument Explorer Select the relevant device by clicking on the required device icon under the MantraCAN heading Instrument Settings CANopen 2 Instrument Settings rie CANBus VCI v2 DSC CANOpen Name ID 00000007F CAN Interface Settings WEIS O o o USB to CAN Compact d Co
23. that would be mainly used by the master SOUT is for backwards compatibility with Version 2 Reading Snapshot SNAP SYSN The action command SNAP samples the selected output by copying SYS to the special result parameter SYSN The main use of this is where a number of different inputs need to be sampled at the same instant Normally multiple readings are staggered in time because of the need to read back results from separate devices in sequence The snap is always carried out on receipt of a valid sync ID The resulting values can then be read back in the normal way from all the devices SYSN parameters Note Instrument Explorer provides wizards for easy calibration of the System stage There are two wizards Sys Calibration Auto and Sys Calibration Table these can be found under the menu item Wizards Control Shunt Calibration Commands SCON and SCOF The Device is fitted with a Shunt calibration resistor whose value is 100K This can be switched across the bridge using SCON giving an approximate change of 0 8mV V at nominal 2 5mV V The command SCOF removes the resistor from across the bridge It is important for the user to remember to switch out the shunt calibration resistor after calibration has been confirmed Digital Output OPON and OPOF For DSC ONLY an open collector output is available This can be switched on using OPON and off by the command OPOF This output is capable of switching 100mA at 30v
24. two wires The temperature sensor is the Dallas 1 Wire digital device DS18520 One connection is ground for which EXC is used and the other is the 1 wire DQ connection which provides the bi directional data line EXC SIG SIG EXC Temp sensor DQ Note EXC provides the ground connection to the optional temperature module For DSC the DQ connection is connected to the I O pin marked TS The temperature module is a small double sided PCB with an 8 pin SOIC integrated circuit mounted to it The dimensions are 10 5 x 7 6 x 2 5mm There are two solder pads for connection to the DSC or DCell A 2mm hole is used for fixing the temperature module to the body of the load cell The module should ideally be positioned as Mantracourt Electronics Limited DCell amp DSC CANopen User Manual 32 close as possible to the strain gauges The IC on the temperature module must also be in good thermal contact to the load cell body so the strain gauges and temperature sensor see the same temperature EXC Da Y Control Parameters The temperature compensation parameters define a pair of lookup tables that contain adjustments to the cell calibration gain and offset over temperature The parameters concerned are the following CTN Number of temperature table points CT1 CT5 C Indicated TEMP value at table point CTO1 CTO5 mV V MV V x10 Offset adjustment at Offset table point CTG1 CTG5 ppm Gain x10 at
25. 19 0 00000056 20 0 00000021 Remember that if the step change in mV V is greater than the value set in FFLV then New Filter Output value New Input Value And the internal working value of FFST is reset to 1 being incremented each update set by RATE until it reaches the user set value of FFST Cell Provides the level where the integration between the DCell DSC and the strain gauge bridge takes place Features include when the optional temperature module is fitted 5 point temperature compensation to produce a temperature compensated value CMVV Scaling using a gain and offset CGAI and COFS respectively producing a value known as CRAW Linearisation using up to 7 points producing the final output from this section known as CELL Over load and under load values can be set in CMIN amp CMAX to alert the user of forces less or greater than the integrator has intended the unit to be operated These features allow the output CELL to be in force units which can be used by System to convert to units of weight Temperature compensation and linearisation are covered in detail in their own chapters Temperature Compensation In Brief When the optional temperature hardware module DTEMP is connected the temperature compensation is available The temperature compensation facility can remove the need for the fitting of compensation resistors to the strain gauges This compensation can apply for gain and offset with up to 5 temperature points
26. 39 Diagnostics LED iii A A A AS A AA A e 39 Chapter 8 CANopenO Communication Protocol cceccscscccsccsccscesscsscssessccssssssssessesscscsssssssssscssesseees 40 CANopen Features SUPport SUMMAPY pess irois seriet iernii neern tusse dT ni rr rr a rr rro enanos 40 Object Dictionary SUMMALY sssccs savvesesieevecieeuceas aia E EEEE dale di AA a is 41 Error M nagement secc A A EE A A Ae 42 Communications Controls sirsie ici io TAI deuamnateneee sands IRA er cidad 42 Data Type Conversions and Rounding cccceece ence ence ence eee eee cence eee e ene e eats eee eeneeeneeeenseeeeeeeeeenseeseeeeaees 43 Chapter 9 Object Dictionary sisshi sci ses ccetectccasecace es deecedeseesssceescdcesceseesseceeacececdeeeetedesessescdessdesecesecc es 44 COMMUNICATIONS Profile Areas sesers enese a airone EONA EE tea pede dda sens sanas cintas 44 Device Description and Communication Specific sesssssssssssssssssssssssessssssssesesesseeeseeeeeeeoeeceeereeeeeesseees 44 Transmit PDO Operation Specific oooooooooccoconononccnncnnnconnconn EE T EE a e o TEE e SEE 45 Transmit PDO M pping Specific s etigen A A a A oA aed 46 Manufacturer Specific Area aia A a T N E ai ine ached TO Mock a AAA a a 47 Ch pter 10 Installation iii eein aessa eai DA AECA RES AAA IA AE A A AS ESENES EA ERGENE 48 Before Installation vario ossaert hE ERER EEEE EERE EE EE EA A tada 48 Physical MOUNCING sensa n A A A A A a tias aa 48 Electrical Protection sisi icc ints
27. 5 to 125 Degree C The resolution of the measurement is 0 0625 Degree C The temperature is sampled and the TEMP variable updated every 5 seconds How to Set Up a Temperature Compensation There are a number of ways of obtaining a temperature compensation curve The best possible compensation for a given piece of physical hardware can only be achieved by performing experiments on that particular unit DCell DSC and associated strain gauges to characterise the measurement output at a variety of different stable temperatures in the required operating range The basic choice of methods depends on trading off ideal accuracy against the complexity of the calibration procedure Method 1 Apply a simple linear drift correction i e for known constant gain and offset changes per degree by specifying zero correction at the calibration temperature and appropriately adjusted correction values at extreme temperatures above and below this This can be used when the measurement or sensor has known temperature coefficients Method 2 Where the temperature characteristics of the measurement are known but not linear a similar scheme to Method 1 can be used with a multi point table defining an approximation to the known ideal temperature curves of offset and gain variations NOTE Both of the above methods are based on known characteristics which could come from datasheets but these methods would not compensate for the DCell DSC Method 3
28. 6 47 USR4 ma DSC v3 16 06 47 05 FF 43 33 50 00 00 00 40 40 16 06 47 06 7F 40 33 50 00 00 00 00 00 16 06 47 USR3 16 06 47 05 FF 43 32 50 00 00 00 00 40 Mantrabus 2 16 06 47 06 7F 40 32 50 00 00 00 00 00 16 06 47 USA2 Dceliv3 16 06 47 05 FF 43 31 50 00 00 00 80 3F 06 47 06 7F 40 31 50 00 00 00 00 00 06 47 USA1 PS 16 06 47 05 FF 48 01 50 00 00 08 OF BF 16 06 47 06 7F 40 01 50 00 00 00 00 00 16 06 47 DSCALON AA 16 06 47 05 FF 48 01 50 00 00 08 OF BF peer vo 16 06 47 06 7F 40 01 50 00 00 00 00 00 go 16 06 47 DSGINTEG w 3 ne AEE Modbus RTU x DCell v3 ma DSC v3 CANBus VG v2 Sh DSC CANOpen Transmit PDOs Click or button to expand or contract this category Instrument Explorer Parameter List When an instrument has been selected from the Select Instrument Window this Parameter List window will become populated The parameters and commands which are available for the selected device will appear in this list in a structured hierarchic manner enabling the user to expand or contract categories by clicking the and amp buttons on the left of the list There are four types of parameters and commands Read write Numeric These parameter values are displayed in the right hand column and can be edited by clicking the value The value can then be changed and pressing the Enter key or moving away prey 0 0 from the edited value will cause the new value to be written to the device There ar
29. AW have been exceeded They are set in Force units On CRAW being greater than the value set in CMAX the CRAWOR flag is set in both FLAG and STAT the value of CRAW is also clamped to this value On CRAW being less than the value set in CMIN the CRAWUR flag is set in both FLAG and STAT the value of CRAW is also clamped to this value Linearisation In Brief Linearisation allows for any non linearity in the strain gauge measurement to be removed Up to 7 points can be set using CLN The principle of operation is that the table holds a value at which an offset is added The point in the table that refer to CRAW are named CLX1 CLX7 The offsets added at these point are named CLK1 CLK7 and are set in thousandths of a cell unit The output from the Linearisation function is CELL If no Linearisation is used CLN lt 2 the CELL is equal to CRAW Linearisation cannot be used at RATE of 8 200Hz A Detailed explanation is given in chapter 6 System System is where the Force output CELL is converted to weight when installed into a system Other features such as SZ offers a means of zeroing the system output SYS Peak and Trough values are also recorded against the value of SYS these are volatile and reset on power up A command SNAP records the next SYS value and stores in SYSN this is useful where more than 1 device in a system and to prevent measurement skew across the system the SNAP command can be broadcast to all devices ready for pollin
30. Do a series of measurements at different temperatures and install the appropriate correction values to give exactly correct results at those same temperatures i e calculate ideal gain and offset corrections at the tested temperatures This method is the most common There is a wizard available in Instrument Explorer which will enable this method to be easily completed by calculating the gain and offset corrections for you Method 4 Use a set of test results to plan a best correction curve not necessarily perfect at test temperatures but slightly better overall NOTES All of these methods can be applied either to data from individual devices or to an average correction for a particular type of sensor hardware During testing temperatures should be measured using the internal TEMP measurement as this is the measurement used to do the corrections For in system tests the environment of the DCell DSC must always be as near as possible to the exact conditions of the eventual in system use Mantracourt Electronics Limited DCell amp DSC CANopen User Manual 34 Parameter Calculations Instrument Explorer provides a Wizard for the calculation of the parameters required by the DSC DCell This is based on Method 3 where data is collected The wizard allows for small changes in the sampled temperature point that may occur when taking a set of results for gain and offset Also taken into account is any variation in t
31. EMPUR TEMPOR ECOMUR ECOMOR CRAWUR CRAWOR SYSUR SYSOR amp LCINTEG 39 Mantracourt Electronics Limited DCell DSC CANopen User Manual Chapter 8 CANopen Communication Protocol This chapter gives details of communication protocols and bus connections This manual only covers CANopen communications The user will need a suitable CANopen bus master application to communicate with DSC Details of suitable solutions are available from Mantracourt on request CANopen Features Support Summary Device Profile Manufacturer defined type 0 NMT support Slave device Boot up Minimum boot up device COB ID Distribution by SDO no DBT support Node ID Distribution by SDO no LMT support PDO s Atx Orx SDO s 1 PDO modes Sync Async Cyclic Acyclic Variable PDO mapping Y Maximum 2 objects PDO Emergency Message Y Life Guarding N Heartbeat Producer Y Additional Notes Changes to NodelD CANbus Bit Rate and PDO communication Parameters will require the device to be power cycled Mantracourt Electronics Limited DCell amp DSC CANopen User Manual 40 Object Dictionary Summary DSC amp DCELL internal data values are mapped into the object dictionary in three distinct areas 1 The main output values are mapped into the Device Profile area at 6000h onward 2 Special control parameters specific to the CANopen version are
32. Outputs From This Are e SRAW is a re scaled and offset adjusted output derived from CELL e SYS is the final output value after removing a final user output offset value SZ from SRAW e SRAWUR and SRAWOR are output warning limit flags In practice SRAW and SYS can be used to represent something like gross and net values Cell and System Scaling Both the Cell and System calibrations are simply linear rescaling calculations i e they apply a gain and offset In both cases four parameters define the scaling offset and min and max limit values These calculations are applied in the following way Output Input x GAI OFS Output min output MAX Output max output MIN In addition if the value exceeds either limit one of two dedicated error flags is set The control parameters thus have the following characteristics e GAI is the multiplying factor set in output units per input unit e OFS is the value that gives zero output set in output units e MAX and MIN are output limit values set in output units The units and functions of the main scaling controls can thus be summarised as Cell Calibration CGAI Force mV V mV V gain factor COFS Force CELL Offset Value CMIN Force Minimum value for CRAW CMAX Force Maximum value for CRAW System Calibration SGAI Eng Force SYS CELL gain factor SOFS Eng SRAW value offset SMIN Eng Minimum value for SRAW SMAX Eng Maximum value for SRAW SZ Eng SYS value off
33. TBC Flags Diagnostics Flags FLAG and STAT All the self diagnostics rely on the FLAG amp STAT parameters which are 16 bit integer register in which different bits of the value represent different diagnostic warnings FLAG is stored in EEPROM and is therefore non volatile STAT is stored in RAM and reset on power up to 0 FLAG is latching requiring reset by the user where as STAT is non latching showing current error status Latched Warning Flags FLAG The flags are normally used as follows FLAG is read at regular intervals by the host like the main output value but generally at longer intervals If some warnings are active i e FLAG is non zero then the host tries to cancel the warnings found by writing FLAG 0 The host then notes whether the error then either remains i e couldn t be cancelled or if it disappears or if it re occurs within a short time and will take action accordingly The warning flags are generally latched indicators of transient error events By resetting the register the host both signals that it has seen the warning and readies the system to detect any re occurrence i e it resets the latch 25 Mantracourt Electronics Limited DCell DSC CANopen User Manual What the host should actually do with warnings depends on the type and the application Sometimes a complete log is kept sometimes no Often some warnings checking at all is needed can be ignored unless they recur within a sho
34. a maximum 330 C for no longer than 2 seconds per pad Excessive heat or increased soldering time may result in damage to the PCB NOTES 1 Solder with water soluble flux should not be used even low residue as this can leave a surface film which attracts atmospheric moisture degrading measurement performance AN 2 DCell units can be damaged by poor soldering due to the small nature of the circuit boards Overheating or applying any pressure to a pad can de solder components on the other side of the board or cause the pad itself to become detached Power Supply Requirements The power supply needed is nominally 5 6 to 18V DC but any possible droop or ripple must be included The devices contain brown out detection which may trigger if the supply voltage at the device drops below the 5 6 volts A single device consumes typically 40mA with a 3500 gauge connected except RS232 output units which use about 10mA more An installation should therefore assume at least 60mA per unit and allow for extra current being taken at power on though supply voltage can safely drop temporarily and for possible voltage drops in long cables Any power supply ripple should be below 100mV and supply arrangements should provide current limiting for fault conditions see Electrical Protection above Cable Requirements Strain Gauge input DSC For optimal performance twin twisted pair with individual shields is recommended this gives goo
35. arameters Summary and Defaults in Chapter 4 The Readings Process Hardware 3 Load Cell problem should be indicated by Flag LCINTEG in STAT 4 Genuine hardware problems usual show up as total failure i e no reading always unchanging usually near zero sometimes always full scale Check wiring take voltage level readings and again if possible use a known good device and set up 5 Check the sensor is connected properly and has some resistance across excitation wires and around 350 Ohms across output wires when disconnected from device 6 Check for damaged DCell DSC device by replacement Mantracourt Electronics Limited DCell amp DSC CANopen User Manual 58 Unexpected Warning Flags Remember that all warning flags in FLAG must be explicitly reset they do not clear themselves when a problem is resolved If a flag cannot be cleared the cause must be persistent i e it keeps happening again This can be immediate regular every few seconds or irregular occasional See Self Diagnosis for precise details of how the individual warnings operate Bear In Mind The Following Possible Problems 1 REBOOT or COMMSFAIL may indicate intermittent connections 2 Where ECOMUR OR or EXCUR EXCOR are triggered suspect input wiring 3 Various range errors CRAWUR OR SRAWUR OR are also likely to be set if the excitation was interrupted EXCUR OR 4 For range errors check the associated limit parameters CMIN MAX SMIN MAX
36. are a number of ways of establishing the correct control values Method 1 Nominal data sheet Performance Values This is the simplest method where the given nominal mV V sensor output is used to calculate an approximate value for CGAI Example A 50 kN load cell has nominal sensitivity of 2 2mV V full scale So to get 50 0 for an input of 2 2mV V we set CGAI to 50 2 2 22 7273 This assumes the output for OKN is OmV V Method 2 Device Standard Calibration Values With some load cells you may have a manufacturer s calibration document This gives precise cell output gain and offset specifications for the individual cell These values can be used to set the SGAI and SOFS values to be used Example A 10 tonne load cell has a calibration sheet specifying 2 19053mV V full scale output and 0 01573mV V output offset CGAI is set to 10 2 19053 0 01573 4 532557 COFS is set to 0 01573 x 4 532557 0 0071297 NOTE Methods 1 and 2 require no load tests This means that systematic installation errors cannot be removed such as cells not being mounted exactly vertical The accuracy is also limited by the DCell DSC electrical calibration accuracy which is about 0 1 The remaining methods require testing with known loads but are therefore inherently more reliable in practice as they can remove unexpected complicating factors relating to installation Method 3 Two Point Calibration Method This is a simple in system calibr
37. at 2000h onward 3 The DCell DSC internal Configuration parameters are mapped at 5000h onward Object Sub 1000 ee FFF O Standard communications area 2000 o UNSIGNED8 R W CANopen6 node id 7 0x7F 2001 E UNSIGNED8 R W CANbus bitrate control Sar 5000 5FFF E SIGNED32 DSC internal parameters 6000 o FLOAT32 RO SYS main value output Scaled E 6001 0 UNSIGNED16 RO DSC FLAG error register ie al SYSN main value Snapped SYS Value 6002 BN FLOAT32 RO The device supports a manufacturer specific device profile with Limited PDO mapping of 2 objects to each Transmit PDO The following communications objects are implemented e SDO e Transmit PDO 1 e Transmit PDO 2 e Transmit PDO 3 e Transmit PDO 4 41 Mantracourt Electronics Limited DCell DSC CANopen User Manual Error Management The DSC FLAG value is mapped to the profile object at 6001h Flags set also cause appropriate bits in the standard Error Register object index 1001h to be set In some cases an Emergency telegram is also broadcast In this case the Manufacturer Specific Error Field simply contains the actual 16 bit FLAG value followed by void bytes When the error condition is removed the error register reverts to 0 and a further NO error emergency telegram is sent if appropriate The error and emergency codes generated by DSC error conditions are the following Bit s
38. ation procedure and probably the commonest method in practice as in the previous example Two known loads are applied to the system and reading results noted then calibration parameters are set to provide exactly correct readings for these two conditions Mantracourt Electronics Limited DCell amp DSC CANopen User Manual 22 E G a 10KN 1 tonne load cell has a CELL reading of 0 120721mV V with no load and 2 21854mV V with a known 100Kg test weight To calibrate this to read in a 1 0 to 1 0 tonne range Calculate CGAI as 0 1 2 21854 0 120721 0 047669 Set COFS 0 120721 x 0 047669 0 005755 Method 4 Multi point Calibration Test For ultimate accuracy to a whole series of point measurements may be taken to determine the best linear scaling of input output Effectively a best line through the data is then chosen and the calibration is set up to follow the line Testing of this sort is also used to establish linearity corrections and similar tests at different temperatures are used to set up temperature compensation see Chapters on Temperature Compensation and Linearity Compensation Note Instrument Explorer provides wizards for easy calibration of the Cell stage There are two wizards Cell Calibration Auto and Cell Calibration Table these can be found under the menu item Wizards Cell Limits CMIN CMAX These are used to indicate that the desired maximum and minimum value of CR
39. ature sensor Other Connections DSC ONLY Resistor RG and track cut TC are used to adjust the mV V sensitivity see Strain Gauge Sensitivity Adjustment below Identifying Bus End Connections DCell Bus Connections Mantracourt Electronics Limited DCell amp DSC CANopen User Manual 50 DSC CAN Versions Bus Connections V and V are the DC power supply and return connections CANH amp CANL are the CAN communications connections GND is a communications ground connection SH is the shield ground used for shielding and grounding only OP is the open collector digital output IP is the volt free digital input TS connects to DQ of the optional temperature sensor Strain Gauge Cabling and Grounding Requirements To achieve full performance specifications and conform to environmental approvals it is important to follow the wiring procedures outlined in this section DCell Strain Gauge Wiring The following diagram illustrates how to wire up a DCell to a strain gauge DCell Strain Gauge Wiring Arrangement Load Cell Body Load Cell Body is Grounded Key Requirements All the load cell wires should be kept as short as feasible at most 20cm The EXC wires should be twisted together also the SIG pair and the two pairs kept apart It is also recommended to secure the wires from moving due to shock or vibration If the DCell is mounted outside the body of the load cell then for optimal performance twin t
40. ature sensor e A 5 way screw connector for power amp CAN comms e A9 way D Type for direct CAN limited to 500Kbps e Link headers for CAN RS232 or RS485 comms selection e Terminating resistor for CAN amp RS485 e LED for power indication e LED for digital output DSC only e Push Switch for digital input DSC only An Evaluation DCell or DSC of your choice ACD ROM containing Instrument Explorer software A 9 way D Type extension lead A USB CAN converter DTEMP temperature sensor for temperature compensation evaluation Other Things you will need e A regulated power supply capable of providing 5 6 18V at 100mA e APC running Windows 98 or above with a spare USB port and 45Mb free disk space and ideally e A strain gauge load cell or simulator 350 5000 ohms impedance Mantracourt Electronics Limited DCell amp DSC CANopen User Manual Checking the Device Type For a DCell the Product Code is one of the following 2 types DLCSCOP Industrial Stability CANopen output DLCHCOP High Stability CANopen output For a DSC card the Product Code is one of the following 2 types DSCSCOP Industrial Stability CANopen output DSCHCOP High Stability CANopen output The CAN bus Identifier ID of a New DCell DSC device is factory set to 127 This can be changed using the CANopen command at Index 2000 subindex 0 Connecting Up The Evaluation Kit Power is supplied to the DSJ1 via the 5 way connector J1 This is c
41. bient temperature Temperature compensation is only provided when an optional module consisting of a digital temperature sensor is wired to the DCell or DSC Purpose and Method of Temperature Compensation Most measurement methods are affected by changes in temperature and uncompensated load cells are especially sensitive having a large overall temperature coefficient Temperature compensation adjusts the measured value in a way that depends on a temperature measurement so that ideally the output does not depend on the current temperature In practice it is usual to refer to a calibration reference temperature The ideal output value is then what the reading would have been if made at the reference temperature The DCell DSC temperature compensation facilities make adjustments to the Cell calibration parameters i e gain and offset which depend on temperature according to a digitally programmed curve These adjustments are automatically applied based on the current device temperature measurement With some care this can remove the need for the usual electrical compensation components altogether Note that the temperature compensation will also remove the temperature drift of the DCell DSC itself if the temperature compensation data is collected when the DCell DSC and strain gauges are tested together as a system Temperature Module Connections and Mounting DTEMP The temperature module is a connected using only
42. cccccncccccnncccconnccconnncconn cnc eens nro eneeeeeeeeseeesaeseeenseeeeeseeeeeas 25 Digital Output OPON and OPONE a 25 Ee EEE E ET eek scan T evade le aetaneds A A a AT 25 Diagnostics Flags FLAG and STA Ti a a a a is Behl 25 Latched Warning Flags FLAG ss srren ve anne A Di Da de 25 1 Mantracourt Electronics Limited DCell DSC CANopen User Manual Meaning and Operation of Elis a A id a AAC 26 Dynamic Stat s Flags STA This a a cata 27 Meaning and Operation Of Flags oooocoooconccoconononcconccnnconn nooo ee eeee eee rn rro o sees nor ai ii a a s 27 Output Update Tracking is cai ii A A dos 27 IAEA NN 28 USRI USRI A NN 28 O AA 28 MTheReset command RSV iii A A A AA A A ca ds 28 WARNING Finite Non Volatile Memory Life ooooocococcconcccnncconcconcnocnco nono no non oo on ro or ron nro nc corno nn ccnnnons 28 Chapter 4 The REadings Process iss is caceeseesseeavisse ss veces esees desde sede seaes ete EE II tees cteeesvee ese Seve saas 29 PLOW IAS FAM wae imoret A A seus see airis 29 Cell and System Scaling wis since cust E EE E els EVRAT EEEE A eyed EEA VNE 30 Calibration Parameters Summary and Defaults cceccceece ence ence ences ne eeeeeeeeeeenseenseeeeeeneeeeeseeeseeeseeneeens 31 Chapter 5 Temperature Compensation siir aureae sens E Er EE So FESTES SSe desedsebasecdscs Ee rS 32 Purpose and Method of Temperature Compensation sssssssssssssssssssssessssssssssessssesesseseseeoceceeeee
43. ct factory If The LED is ON for the majority of time then Flashes OFF for 100mS then a fault exists This Fault can be read back using the communications Likely causes of this are Strain Gauge Integrity error or Limits reached for MVV CRAW SRAW or TEMP First check the connections to the strain gauge are correct Next check the input is not over range or the limits set for CMIN CMAX SMIN or SMAX have not been exceeded No Communications The majority of problems involve a failure to communicate as there are a number of optional settings that must be set the same at both ends of the link For this reason any communications application should always check command responses and flag a problem when there these responses are not activated Possible problems can be categorised according to where in the chain of communication the problem may be The typical chain runs as follows e PC software port connection baud rate Node ID protocol e PC USB working e PC CAN drivers e USB CAN device e Bus wiring e Device wiring ID bit rate working Bad Readings The cause can be either hardware or software related Software 1 Check the MVV reading first and ensure it is correct This figure is the RAW input and is not affected by the user configurable calibration settings 2 If MVV looks correct check the calibration settings step by step Consider resetting all the calibration controls to default values see Calibration P
44. d further use of miniaturisation the cost is now lower e Real mV V calibration Instead of full scale the base measurement is in mV V and is factory calibrated to within 0 1 the of FS output ELEC is still available e Extreme Noise Immunity 5 x heavy industrial level e Diagnostics LED An LED is used to indicate that the device is powered and working correctly The LED is also used to indicate which protocol the device is e Remote shunt cal A 100K 1 50ppm Deg C resistor can be switched across the bridge to allow load cell integrity to be established e Peak amp Trough Measurements Added to allow the faster rates to hold a peak or trough readings These are stored in volatile memory amp are therefore reset on power up e Programmable dynamic filtering The filtering is the same as used on Version 2 but with the advantage of being able to set the characteristics using the communications e Wide Operating Voltage The operating voltage is now 5 5 to 18V allowing the device to be powered from a wider range of available system supplies e DC Excitation DC excitation has now been employed allowing longer cable lengths for the load cells which is particularly useful for DSC This is a 4 wire measurement 5 Mantracourt Electronics Limited DCell DSC CANopen User Manual e Scaling implementation has been changed for both CELL and SYS The gain is applied before the offset thus following the more standard approach
45. d noise immunity Maximum length should not exceed 20m Normal 4 core shielded cable can be used in areas of low electromagnetic noise Power and Communication Again twin twisted pair cable is recommended for this The cable should have the following characteristics e Twisted pair with independent shields e Characteristic impedance 50 150 ohms e Core to core and core to shield capacitance below 300pF m A suitable type is BICC Brand Rex BE56723 also equivalent to Belden type 8723 In the UK this is available from Farnell part number 118 2117 Temperature Sensor A shielded twisted pair is recommended with a maximum length of 10m the shield being connected to the load cell body or CH if DSC For short lengths lt 2m in a low noise environment inside load cell body for example then normal cable can be used 49 Mantracourt Electronics Limited DCell DSC CANopen User Manual Identifying Strain Gauge Connections DCell Input Connections EXC SIG SIG EXC Temp sensor DQ The Optional Temperature sensor has two connections DQ which provides the bi directional data line and EXC which provides the Ov connection DSC Input Connections Strain Gauge Bridge Connections Are As Follows e EXC positive negative excitation supply e SIG positive negative output signal e SH Shield connection for shield of strain gauge cable e GND can be used as the ground connection for the temper
46. e Object dictionary index to be mapped Third byte is object dictionary sub index Forth byte is the required data length Note The TxPDOs defaults have been mapped to the Manufacturers Specific Profile Area and not the Standardised Device Profile Area Name refers to the Instrument Explorer Name Mantracourt Electronics Limited DCell amp DSC CANopen User Manual 46 Manufacturer Specific Area Name Description Access Object Dictionary Object Dictionary Index Sub Index CMVV Temp Compensated mv V______ RO f5000h_ ______ STAT Status JRO omn S o OE MVV Filtered amp factory calibrated mV V RO 5002h SOUT Selected output copy of SYS RO 5003h SYS Main output RO 5005hand 6000h_ 0 TEMP Temperature RO foosh bo SRAW Raw System output Ro soon bb o O CELL Cell output Ro foon O S O O O E RR IE CRAW Raw cell output RO 500Ah ELEC Electrical output RO foh o S O SZ System zero RW orn a SYSN epapshat result RR agoh and 60mm AS PEAK Peskvalve JRO__f500Eh E SERL serie number low 5010h SERH Seriat umber high fo fo RATE gee o S 4 NMVV Romina mi for O at CGAI Cellgain RW boh O CMIN range min RW 5018h CMAX Cell range max RW boh CLN e e A CLX1 7 Linearisation raw values Rw _ 5O1Fh 5025h___ 0 0 CLK1 7 Linearisation corrections RW 5026h 502Ch SGAI System gain RW 502Dh SOFS System offset RW oem CO i O SMIN System range min RW orn gt gt gt o 363
47. e are now calibrating at system level we have a choice of two calibration methods Sys Calibration Table This technique is used when a manufacturers calibration document is available for the connected strain gauge This normally gives mV V to engineering unit values Sys Calibration Auto This technique is used when the input can be stimulated with real input values For example you have access to test weight forces We will now describe each of these techniques with an example Sys Calibration Table A 10 tonne load cell manufacturer gives the following data mV V output Force 2 19053 10 tonne 0 01573 0 tonne Start the wizard by selecting Sys Calibration Table from the Wizard menu A SYS Calibration Table Instructions This Wizard will allow you to calibrate your instrument by entering input values and required values which can be based on manufacturers tables You will need to know two CELL levels and the required SYS values at these points The two levels of input should be around 25 or below of full scale for the lower value and a high level at around 75 or higher of full scale Press NEXT to continue with the calibration 15 Mantracourt Electronics Limited DCell DSC CANopen User Manual Click the Next button and enter the low values as shown below A SYS Calibration Table Enter Low Data Enter the low level input value and required output value Enter value for CELL at this l
48. e calculated as follows New Filter Output value Current Filter Output Value Input Value Current Filter Output Value FFST The time taken to reach 63 of a step change input which is less than FFLV is the frequency at which values are passed to the dynamic filter set in RATE multiplied by FFST The table below gives an indication of the response to a step input less than FFLV Update Rate is 1 table value of RATE see Chapter 3 Output Rate Control Of Final Value Time To settle 63 Update Rate FFST 1 Update Rate FFST 5 0 1 Update Rate FFST 7 For example If RATE is set to 7 100Hz 0 01s and FFST is set to 30 then the time taken to reach a of step change value is as follows Of Final Value Time To settle 63 0 01 x 30 0 3 seconds 1 0 01 x 30 x 5 1 5 seconds 0 1 0 01 x 30 x 7 2 1 seconds The following table shows the number of updates x FFST and the error New Filter Output value will differ from a constant Input Value x FFST Error 1 36 7879441 2 13 5335283 Mantracourt Electronics Limited DCell amp DSC CANopen User Manual 20 3 4 97870684 4 1 83156389 5 0 67379470 6 0 24787522 7 0 09118820 8 0 03354626 9 0 01234098 10 0 00453999 11 0 00167017 12 0 00061442 13 0 00022603 14 0 00008315 15 0 00003059 16 0 00001125 17 0 00000414 18 0 00000152
49. e no checks on the data entered and it is up to the user to enter the correct data Mantracourt Electronics Limited DCell DSC CANopen User Manual 12 Read Only These parameter values are displayed greyed out and cannot be changed Read write Enumerated These parameters can only be changed by BPS 0 selecting the new value from a drop down list Clicking in the right hand column will display a down arrow button which BPS 0 y when clicked will display the parameter value options in a list Note that all enumerated data apart from on off will be displayed with BPS a numeric value hyphen then the description of the value IDSIZE The numeric value is the value of the parameter and the description is CAN Bus just there to help Streaming Commands These commands have Click to execute displayed in the RSTEMPUR Click to execute right hand column Clicking here will display a L J button Click this to issue the command to the device Click to execute y As parameters are changed the communications traffic is displayed in the Traffic Pane If any errors occur these will be shown in red in the Error Pane Once an error occurs it will need to be reset before any more communications can take place Reset errors by either right clicking the Error Pane and selecting Reset Errors from the pop up menu or select the Communications menu and click the Reset Errors item To manually refresh the parameter list cl
50. e second for the reset procedure to complete and measure cycle to start With RATE set to 0 you should be able to see the SYS update rate slow to once a second and the noise level should also noticeably decrease All the main reading output values are updated at this rate Rate does not change the rate at which temperature output TEMP is updated Important Note For A RATE of 8 200Hz Temperature compensation and Linearisation cannot be used due to Calculation time required Dynamic Filtering FFST and FFLV The Dynamic filter is basically a recursive filter and therefore behaves like an RC circuit It has two user settings a level set in mV V by FFLV and a maximum number of steps set by FFST maximum value FFST can be is 255 If a difference between a new input value RMVV and the current filtered value MVV is greater than FFLV then the fractional amount of the new reading added to the current reading is reset to 1 that is to say that output of the filter will be equal to the new input reading If the difference is less than FFLV then the fractional amount added is incremented until it reaches the maximum level set by FFST IE if FFST 10 then after a step change the fractional part of a new reading is incremented as follows 1 1 1 2 1 3 1 4 1 5 1 6 1 10 1 10 1 10 This allows the Filter to respond rapidly to a fast moving input signal With a step change which does not exceed FFLV the calculated new filtered value can b
51. eeeeesseees 32 Temperature Module Connections and Mounting DTEMP ssssssssssssssssssssssssssssssssssssseessseoeceeeeeeeeeessesees 32 Control Para meters indian des EE EEE AE a ii ds 33 Internal Calculation ieceri re iroiiasiii iden io reesei E AEE EE EEEREN EE EAEE ES KERV REEE e Aia 33 The Temperature Measurement oooooccoccnonccononononoconconn E EEEE e Te e E EE a iea 34 How to Set Up a Temperature Compensation ss ssscsseseecsossesessocsssssocssosossoesessisosssssssessesceecssssssosesssessee 34 Parameter Calculations sso cusses desiit onw Ea E EE ced os ERREEN EENE ECEE EIERNE EEEE 35 Chapter 6 Linearity Compensation ccssccecccsccccsceescessccesceesccesscessseenseeesessseessseessseesessseeseesaeeees 36 Purpose and Method of Linearisation oooococococoncconccnnconnconorooncncor ron non eens E aaa E e Saaai 36 Control Parameters lt a cissiesacncese ede vssed ieissa cae deahenseudiecdseseaedestvadendssenwadsdsvcesnseessudba ee adidas 36 Internal Calculation a A a 36 How to Set Up Linearity COMPENSATION cece cece e eee e eee e ene e eee nooo rr rre r rr rr EPONE i riran 37 Parameter Calculations and Example cccceccececeenceene cence eee sence ene ron r ron ron sense eneeeeeseeeseeeeeenseeeeeeeaees 37 Chapter 7 Self DiaQnostics oo3sscdscs cccsedce cane ceccawedsvcescseneacesecese ee sade AAA cee seddecdeu sede sess qeceseeeeed sowedewendes 39 Diagnostics Flags ii A S00 Laas ab A A A AA gerd a
52. erwise i is chosen so that Ti lt T lt Ti 1 Once an index into the table has been established the gain value to be used is extrapolated between the index value and the value above If the temperature is above CT CTN or below CT1 then the calculated temperature gain value is extrapolated from CT CTN 1 to CT CTN or CT1 to CT2 respectively This can be represented mathematically as follows CALC_CTG CTGi CTGi 1 CTGi x T CTi CTi 1 CTi The actual gain value used is 1 CALC_CTGO x 10 6 and is multiplied by the uncompensated value MVV The offset correction is then applied Using the same temperature index i as found for the GAIN index above 33 Mantracourt Electronics Limited DCell DSC CANopen User Manual The Offset value is extrapolated between the same two temperature points This can be represented mathematically as follows CALC_CTO CTO CTOj 4 CTOj x T CTi CTi 1 CTi The actual offset value used is CALC_CTO x 10 and is subtracted from the above gain adjusted value The output from the temperature compensation CMVV is then calculated as CMVV MVV x 1 CALC_CTGO x 10 CALC_CTO x 10 The Temperature Measurement The temperature sensor used is a Dallas MAXIM DS18520 Digital Thermometer using the 1 Wire bus technology This gives a temperature measurement accuracy of 0 5 Degree C over the temperature range 10 to 85 degree C and 2 0 Degree C over temp range 5
53. est loads For test load of x1 OKg E CELL reading c1 0 0010 For test load of x2 100 13Kg CELL reading c2 100 44 For test load of x3 199 72Kg CELL reading c3 200 57 For test load of x4 349 97Kg CELL reading c4 349 75 For test load of x5 450 03Kg CELL reading c5 449 98 We choose these precise test points as our linearisation reference points so CLN 5 CLX1 0 0010 CLX2 100 44 37 Mantracourt Electronics Limited DCell DSC CANopen User Manual Note on the Example If you graph the errors from the above example the results look like this 0 4 0 2 0 0 2 0 4 0 6 0 8 1 This doesn t show any very definite linear trend so the calibration is okay However there is a big jump between points 3 and 4 which might be worth a more detailed investigation Some important features of the error curve could have been missed by the test Mantracourt Electronics Limited DCell DSC CANopen User Manual 38 Chapter 7 Self Diagnostics Diagnostics Flags The main diagnostics facilities are by means of the flags See chapter 3 Flags for a full description of the flags and their meaning The flags are normally used something like this FLAG is read at regular intervals by the host like the main output value but generally at longer intervals If some warnings are active i e FLAG is non zero then the host tries to cancel the warnings found by writing FLAG 0 The host then notes w
54. fer to DCell amp DSC CAN 2 Generation Manual These variants are sufficiently different to require their own manuals The following order codes are supported by an earlier version manual DCell amp DSC Version 2 DLCPKASC DLCPKMAN DLCPKMOD DSC2AS DSC2MA DSC2MB DSC4AS DSC4MA DSC4MB Mantracourt Electronics Limited DCell amp DSC CANopen User Manual Some Application Examples Simple Distributed Measurement Pressure loads are taken at a number of keys points in a manufacturing process distributed over a large area Each pressure sensor contains a DCell unit and all the sensors are connected by a single cable carrying power and CAN communications A central PC allows continuous display monitoring and logging of all values from a central control room This displays a control panel and current display window and logs information to an Excel spreadsheet for future analysis Further monitoring checks and displayed information can easily be added when required to the system where up to 127 nodes can be installed Low Cost Dedicated Weighing Station A basic load cell weighing pad device has a cable leading to a wall mounted weight display Digital Load Cell Load cell products are offered with a high precision digital communications option A DCell is fitted into the gauge pocket of each load cell in manufacture During product testing each unit undergoes a combined load test and temperature cycle Each unit is the
55. fferent corner readings If it exceeds a programmed limit a command to the I O card turns the relay on Total weight is calculated by summing the individual results mathematically Automatic re zeroing occurs when the total is near zero for more than a few seconds A control button enables a set up mode for recalibration protected by operator password which displays individual readings and total Corner compensation can be checked by observing the changing total as a weight is moved around Simple button presses control two point recalibration for any cell 7 Mantracourt Electronics Limited DCell DSC CANopen User Manual Chapter 2 Getting Started with the Evaluation Kit This chapter explains how to connect up a DCell DSC for the first time and how to get it working For simplicity this chapter is based on the standard DCell DSC Evaluation Kit which contains everything needed to communicate with a puck or card from your PC It is advised that first time users wishing to familiarise themselves with the product use the Mantracourt Evaluation Kit This provides a low cost easy way to get started If you do not have an Evaluation Kit the instructions in this chapter mostly still apply but you will need to wire up the device and possible bus converter and have some means of communicating with it The Evaluation Kit Contents e An Evaluation PCB DSJ1 which comprises of e A 8 way screw connector for the strain gauge amp Temper
56. g of their individual SYSN values System Scaling SGAI SOFS The cell output value CELL is scaled with gain and offset using SGAI and SOFS respectively The gain is applied first and the offset the subtracted This would be used to give a force output in the chosen units this output being termed SRAW SRAW CELL X SGAI SOFS If we have two cell output CELL readings for two known test loads we can convert the output to the required range So if Test load xA gt CELL reading cA Test load xB gt CELL reading cB Then we calculate the following gain value SGAI xB xA cB cA 23 Mantracourt Electronics Limited DCell DSC CANopen User Manual And then the offset SOFS cA x SGAI xA The outputs should now be SRAW xA xB true load values as required Example of calculations for SGAl and SOFS Example A 2500Kgf load cell installation is to be calibrated by means of test weights The cell calibration gives an output in Kgf ranging 0 2000 A system calibration is required to give an output reading in the range 0 1 0 tonnes Calculations Take readings with two known applied loads such as For test load of xA 99 88Kg CELL reading cA 100 0112 For test load of xB 500 07Kg CELL reading cB 498 7735 Calculate gain value In this case put SGAI xB xA cB cA 0 50007 0 09988 498 7735 100 0112 0 001003580 1 003580x10 Calculate offset value In this case SOFS
57. ge in transit Mantracourt warranty does not apply to defects resulting from action of the buyer such as mishandling improper interfacing operation outside of design limits improper repair or unauthorised modification No other warranties are expressed or implied Mantracourt specifically disclaims any implied warranties of merchantability or fitness for a specific purpose The remedies outlined above are the buyer s only remedies Mantracourt will not be liable for direct indirect special incidental or consequential damages whether based on the contract tort or other legal theory Any corrective maintenance required after the warranty period should be performed by Mantracourt approved personnel only aby ISO 9001 REGISTERED FIRM THE QUEEN S AWARDS D 2 FOR ENTERPRISE Fa y AMS C In the interests of continued product development Mantracourt Electronics Limited reserves the right to alter product specifications without prior notice Designed and Manufactured In the UK Code No 517 160 21 01 10 63 Mantracourt Electronics Limited DCell DSC CANopen User Manual
58. hardware sensitivity to avoid saturating the input If it is less you can correct in software alone but increasing sensitivity will generally improve accuracy To adjust the mV V for DSC an extra resistor Rg is fitted across the pads RG as shown above in Identifying the DSC Rg Resistor RG TC Identifying Sensor End Connections The link across TC can be cut to disconnect the internal 100R gain resistor This is needed for lowering the sensitivity The resistor is 0805 size surface mount chip A 0 1 5ppm Deg C resistor for the high stability version 25ppm Deg C for the Industrial must be used to maintain performance Reducing Sensitivity To accommodate a maximum sensor output larger than 2 5mV V it is necessary to reduce the electrical sensitivity of the input circuitry To decrease sensitivity the link TC is cut and the value of the resistor fitted in Q should be Rg required mV V x 40 Example For 10mV V Rg 10 x 40 4000 Mantracourt Electronics Limited DCell amp DSC CANopen User Manual 56 Increasing Sensitivity When the full scale output is smaller than 2 5 mV V it may be desired to increase sensitivity However it is often possible instead to compensate partly or entirely in software by increasing a software gain control CGAI or SGAI To increase sensitivity TC is left in place so that the fitted Rg appears in parallel this gives better temperature stability Its value should
59. he test weights at different temperatures This is a complex mathematical procedure which is best solved by a PC programme such as the wizard 35 Mantracourt Electronics Limited DCell DSC CANopen User Manual Chapter 6 Linearity Compensation This chapter describes the Linearity Compensation features and how to use them Purpose and Method of Linearisation Load cell sensor outputs are never precisely proportional to the input applied load If the graph of the measurement output against the true value shows slight deviations from the ideal straight line then slight errors remain even when the basic calibration offset and gain is as good as possible Linearity compensation adjusts the raw measurement by a small amount that is calculated as a function of the raw measurement value itself Ideally this will adjust the output response for any given input load by exactly the right amount to place the final result onto the ideal straight line The DCell DSC non linearity compensation uses a single lookup table similar to those used for temperature compensation see previous chapter This provides a linearly interpolated compensating value with up to 7 control points which is then added to the output result Generally linearisation is a finer level of compensation than temperature compensation It should only be applied after the basic Cell calibration and temperature compensation if any have been set up Although the tests
60. hether the error then either remains i e couldn t be cancelled or if it disappears or if it re occurs within a short time and will take action accordingly The warning flags are latched indicators of transient error events By resetting the register the host both signals that it has seen the warning and readies the system to detect any re occurrence i e it resets the latch What the host should actually do with warnings depends on the type and the application Sometimes a complete log is kept sometimes no checking at all is needed Often some warnings can be ignored unless they recur within a short time Warning flags survive power down i e they are backed up in non volatile EEPROM storage Though useful this means that repeatedly cancelling errors which then shortly recur can wear out the device non volatile storage see WARNING Finite Non Volatile Memory Life in chapter 3 STAT provides a current status of the device These flags are not latched and not saved on power fail Diagnostics LED A new feature for Version 3 is the addition of an LED to indicate the current status of the device If all is healthy the LED should flash ON for a period of 100mS The rate at which the LED flashes is 0 5 second If an error conditions occurs which is based on any of the following error flags being set then the operation of the LED will invert IE the LED will flash off for 100mS at the rate set in the table above These flags Being T
61. hich parameters and generated variables belong This provides a convenient method for describing the functionality and purpose of each The categories can be seen from Instrument Explorers Parameter List pane and are as follows Information Reports the current version of the devices software and the devices unique serial number Note that VERSION is the read able item derived from the devices internal value of VER and SerialNumber is derived from SERL and SERH Software Version VER The VER parameter read only byte returns a value identifying the software release number coded as 256 major release minor release where MSB of VER is major release and LSB of VER is minor release Eg current version 3 1 returns VER 769 256 x 3 1 Serial Number SERL and SERH SERL and SERH are read only integer parameters returning the device serial number This is decoded as 65536 SERH SERL The VisualLink Instrument Explorer software drivers include a convenience Serial Number property that automatically does this Strain Gauge This is where the measurement process starts If the optional temperature module is fitted then TEMP will display actual temperature in Degree C Otherwise TEMP will display 125 Degree C RATE is the parameter that selects measurement cycle update rate mV V output MVV MVV is the factory calibrated mV V output and it is this value that all other measurement output values are derived from Factory calibratio
62. ick the amp button on the toolbar or select Sync Now from the Parameters menu Now you have successfully established communications with your evaluation device the next step is to perform a simple calibration Connecting a Load Cell You can now connect a strain gauge bridge load cell or simulator to the DCell DSC A suitable strain gauge should have an impedance of 350 5000ohms and at least for now a nominal output of around 2 5mV V 13 Mantracourt Electronics Limited DCell DSC CANopen User Manual DSJ1 Evaluation Board Sensor Connections DSJ1 SH EXC SIG SIG EXC SH EXC Optional Temperature Sensor DTemp DQ See Chapter 10 for Connection Method to Strain Gauge See Chapter 5 for Connections to Temperature Sensor Module Next Instrument Explorer will set to automatically update dynamic parameters from the device so that we can see values as SYS changing on the shield To do this either click the 2 button on the toolbar or click on the Parameters menu and select the Auto Sync item Note that these options toggle so be sure to leave your selection in the active state From the Parameter List click the t next to the System heading to expand this level The Parameter List should look as follows ood eit This now exposes more levels that can be expanded as Scaling required by clicking the next to the heading name Limits SZ 0 0 SNAP Click to execute Peak Tr
63. justment DSC ONLY sssssssssssssesessssssseseesssssseeeessesseeeesesessseseeeeessssseeeeessses 56 Identifying the DSG Rg RESIStOM vrai a chs ESEE eos EEEE Suen wad sea A a es 56 Chapter 1 1 ProuDleshOOting lt a A 58 LED Indicador vicio oct rin esha doseadeuds a dd ed baina 58 NO COMMUMICALIONS a TEE ES aa aa A a ti sists site Aia 58 A sted ce tel A dagbahedueede suas anegee sees Sees Si edesugeedh geuhwabas gees me eeecgssecesaens 58 Unexpected Warning Flags ccvici ntorocon anotan eden vedas cess cWaleciaieenaiesased seeded such Vawelededeucdeecdeeeeb s danese dade dusalen 59 Problems with Bus Baud Rate iscsi cei scccsssonvessseteaea se coc cmsnseadidaes acd evbsscoasiaees te sbvsdedesesha sescdisevedessevsesvesedede 59 Recovering a lost DEEL DS Cirine g ve eases a VEE ce Eo sae Rede A A sO dhe need dae aia ok 59 Resetting to default ID oiriin sees ira A A A RS AAA A eva RARA 59 First Commands sieer a a A EE A AAA eens ooaveeevenceess 59 SECONA COMME in 59 Chapter 1 2 Specifications ssesisass isssiwes iii eiii aida iii 60 Technical Specifications DSC DCELL High Stability oooooocooccoocccnccnonaconononononcconncoorccon crono conc cnn roca cons 60 Technical Specifications DSC DCell Industrial Stability oooocooccoocccoccconcnoncnonnconnconccconoroncconcccnnnona nono 61 Mechanical Specification for DSC c c cc secccsdevsccccssccntetennceceessseccsccctensecdseeeneeeaessdsueccedsevcsesescseeevaeedan 62
64. ly Devices are protected against shorting of communications lines to power supply and shorting of sensor inputs No over current protection is provided in case of faults so the supply arrangements should ensure adequate power limiting or fusing NOT PROTECTED AGAINST REVERSE POLARITY OF SUPPLY Moisture Protection Both DCell and DSC must only be operated in a dry environment as moisture can dramatically degrade the measurement performance DCell Will normally be sealed into a load cell pocket While flexible silicone sealant can be used to completely embed the unit this is not adequate moisture protection in itself If required the entire unit can be embedded in a potting compound A two part epoxy compound can be used but bubbles and gaps must be avoided to prevent mechanical stress which could break the device Mantracourt Electronics Limited DCell amp DSC CANopen User Manual 48 The compound used must be specified for electrical use and have sufficient thermal conductivity to cope with the heat given off up to 1W on a 15V supply DSC no additional electrical shielding is required but moisture and or mechanical protection are often required Any simple box or enclosure can be used If metal the enclosure should be grounded to the SH connection see Communications Cabling and Grounding Requirements below Soldering Methods Take care soldering cables to the pads Use a temperature controlled soldering iron set to
65. ly be used repeatedly For the same reason automatically cancelling warning flags must also be implemented with caution It is okay as long as you are not getting an error recurring repeatedly and resetting it every few seconds Mantracourt Electronics Limited DCell amp DSC CANopen User Manual 28 Chapter 4 The Readings Process This chapter gives an account of the reading process except for the linearity and temperature compensation processes which have their own chapters later on Flow diagram Electrical MMV delas x 100 CTGx Ctx CTOx Ctx The underlying analogue to digital conversion rate is 3 255Khz These results are block averaged to produce the required output rate set by the RATE control This block averaged result is then passed through the dynamic filter at the same rate and then into the chain of above calculations The named values shown in the boxes are all output parameters which can be read back over the comms link The diagram shows three separate calibration stages called the Electrical Cell and System This allows independent calibrations to be stored for the device itself the load cell and the installed system characteristics Electrical The Electrical calibration produces corrected electrical readings from the internal measurements This is factory set by Mantracourt during the production process The main outputs from this are e MVV is the fact
66. n Instrument Explorer Do e Save and restore customisable user workspace e Read and Write individual instrument parameters e Save and restore parameter configurations e Log data to a window or file e Perform calibration and compensation Installing Instrument Explorer Install the Instrument Explorer software by inserting the CD in the CD ROM drive This should start the AutoRun process unless this is disabled on your computer If the install program does not start of its own accord run SETUP EXE on the CD by selecting Run from the Start Menu and then entering D SETUP where D is the drive letter of your CD ROM drive 9 Mantracourt Electronics Limited DCell DSC CANopen User Manual The install program provides step by step instructions The software will install into a folder called InstrumentExplorer inside the Program Files folder You may change this destination if required Shortcut icons can be created on your desktop and shortcut bar After installation you may be asked to restart the computer This should be done before proceeding with communications When given the option to install IXXAT CAN drivers ensure these are selected which is the default Running the Instrument Explorer Software Having installed Instrument Explorer you can now run the application which the rest of this chapter is based around From the Windows Start button select Programs then Instrument Explorer or click on the
67. n iaa EEEE a ER ES AENDE EE E ias 48 Moisture Protections ission geren SEA N AA E A a deis 48 Soldering Methods 2 A E a A E ae ee ee 49 Power Supply Requirements 1 A Sales Saeko ae eee OVIE EEEE Sain ba Ca dale BON CSETE AA AAA 49 Gable Requirements Aaa tn dees 49 Strain Gauge Input DCi a a a e di PE a le SEKERES 49 Power and CommMunicatiON i esesoncooonocconorcocancecanano cc cmsesedtedauensdedesdcosdedecsasdeossesesesaans idas ono e eSEE 49 Temperature SEnSOM cece HS A A A A A cede A EREA 49 Identifying Strain Gauge CONNECTIONS ccccesce cece esc e ences ee ee eee nese sees nese E a A T Ee EE EEEE 50 DGell INPUt CONNECLIONS ia A dees A See OURS han alae a vo ao AAA E Daten AE a 50 DSC Input Comme ction ense ensems e tE tivo sad 50 Identifying Bus End CONNECtIONS sj ii a A A A dit Beds 50 DCell Bus COnnectiOnsss sosise tens onda ias dd bits 50 Mantracourt Electronics Limited DCell DSC CANopen User Manual 2 DSC CAN Versions Bus CONNECTIONS cccccceccccccccccceeececceeeeeeeeeeeeeeeeeseeeeeeeeeeeeeceeeeeeeeeeeeeeessseeeeeeeeeess 51 Strain Gauge Cabling and Grounding Requirements ccsccesceenccencenee ence eeeeeeneeenseeeeeeeeeeeeseeeseenseeeeeens 51 DCelUStrain Gauge Wiig ves ce cwncs ces vedas A 4 eid ed da dllviee all s a a i 51 DCell Strain Gauge Wiring ArranGeEMeNnt cecce cece esc eene cence eeeeeeee eens sense eee eeeeeenseeneseeeseeneeeeeeenseeeeeeeaees 51 Key R quirementS iia A a
68. n is within 0 05 Nominal mV V level NMVV This is used to represent the nominal mV V value representing 100 of full scale This value is used solely for the generation of ELEC It is factory set for 2 5mV V If the electronic gain is adjusted by changing the gain resistor then if ELEC is used NMVV value must be changed to represent the new nominal mV V mV V Output In Percentage Terms ELEC This is mainly for backwards compatibility with Version 2 It is the mV V value represented in percentage terms 100 being the value set by NMVV Temperature Value TEMP If the optional temperature module is fitted DTEMP then TEMP will display actual temperature in Degree C Otherwise TEMP will display 125 Degree C TEMP is used by the temperature compensation See chapter 5 Output Rate Control RATE The RATE parameter is used to select the output update rate according to the following table of values RATE value 5 update rate readings per 1 2 second The default rate is 10Hz RATE 3 The other settings give a different speed accuracy trade off Invalid RATE values are treated as if it was set to 3 19 Mantracourt Electronics Limited DCell DSC CANopen User Manual The underlying analogue to digital conversion rate is 1627Khz These results are block averaged to produce the required output rate To Change The Output Rate 1 Set RATE to the new value 2 Click on the RST button to reboot the device 3 Wait for on
69. n programmed with individually calculated gain offset linearity and temperature compensation tables All units perform to a very tight specification without the use of any trimming components High Reliability Load sensing A road bridge has a dedicated load monitoring and active control computer system System calibration adjustments are only established during construction so sensors must be replaceable without recalibration Each load monitoring point has a digital load cell fitted with calibration values set during construction Self diagnostics aid detection of failures When a failed load cell is replaced it will produce identical force measurements The old load cell set up data values are programmed into the separate user level calibration store in the unit to produce an identically performing replacement Load Balance Monitor A lorry loading weighpoint monitors left right load balance and sounds a warning if loading is too uneven for safety A drive on weighing platform is provided with load cells at each of four corners Each cell is wired to a DSC unit and these are cabled to a 3 party LCD display and control unit producing a complete turnkey system A digital 1 0 card is wired to the same bus to control the warning alarm Application software running on the control unit provides a left right balance readout with a graphical tipping display and a total weight indication The balance indication is calculated by comparing the di
70. ntrol allows removal of an arbitrary output offset enabling independent readings of net and gross measurement values Dynamic Filtering Gives higher accuracy on stable inputs without increased settling time Programmable Output Modes Output rate control enables speed accuracy trade off ASCII output version provides decimal format control and continuous output mode for dumb terminal output Unique Serial Number Every unit carries a unique serial number tag readable over the communications link Communications Error Detection CAN transmit and receive error counts along with CAN bus status can be read from the device External Temperature Sensing optional An external temperature module for improved accuracy especially tracking changing temperature conditions Software Reset A special communications command forces a device reboot as a failsafe to ensure correct operation Version 3 Additions and Enhancements The following are an outline only more detail will be found further on in this manual DCell e Easy mounting via a 2mm screw e Connection via solder holes to either side of PCB e Lower profile dual PCB construction e Additional I O e Easier shielding connection at load cell connector end DCell amp DSC e Bit rates to 1 Mbps e Higher sampling rate Sampling to 200Hz can now be achieved Also more sampling rates are available as follows 1 2 5 10 20 50 60 100 200Hz e Lower cost With new technology an
71. ntroller Channel Baudrate 1D Type lo v 125KB ov Bt Global Mask Global Value 00000000 00000000 e Select the ID The factory default is 127 decimal 7F HEX e Select the baud rate to which the device is set The factory default is 125KB e Select the ID type Default is 11Bit standard note extended not supported e Now click the OK button The above assumes factory defaults If your device is known to have different settings use these instead of the ones stated above 11 Mantracourt Electronics Limited DCell DSC CANopen User Manual Viewing Device Data The following main parameter list should now appear in the central pane W instrument Explorer aaa TE A Parameters Watch Logging so Macros View Help SN rio A Comms Traffic x 06 47 05 FF 43 39 50 00 00 00 10 41 a noe 06 7F 40 39 50 00 00 00 00 00 6 47 USRS te 47 05 FF 43 38 50 00 00 00 00 41 standard 06 47 06 7F 40 38 50 00 00 00 00 00 ADWAS 06 47 USAB standard 16 06 47 05 FF 43 37 50 00 00 00 E0 40 ENE 16 06 47 06 7F 40 37 50 00 00 00 00 00 wa standard 16 06 47 USR7 16 06 47 05 FF 43 36 50 00 00 00 CO 40 Da VABIS 1806 47 06 7F 40 36 50 00 00 00 00 00 standard 06 47 USRE 16 06 47 05 FF 43 35 50 00 00 00 40 40 16 06 47 06 7F 40 35 50 00 00 00 00 00 MantraASCI 2 16 06 47 USAS 16 06 47 05 FF 43 34 50 00 00 00 80 40 gg cel 16 06 47 06 7F 40 34 50 00 00 00 00 00 3 10Hz 16 0
72. o Twisted Pair CAN GND L PSU 1 Tr eee Note The specified cable above shows a yellow wire this will be replaced with a white wire 55 Mantracourt Electronics Limited DCell DSC CANopen User Manual Key Requirements e The main bus c able must be terminated at either end e Where the bus does not go directly to each attached device each stub cable connecting to the bus should have just one device on it e Stub branches should be kept as short as possible e Stubs are not terminated Bus Layout and Termination The ideal bus is a single length of cable terminated at either end Each end connects to a communicating device while other devices are connected as near as possible directly to the main bus as it passes them i e not on long side branches The bus must be terminated at both ends to avoid reflections Connecting a 120 Ohm resistor between the CANH and CANL lines does this Loading It is important that the bus is loaded at each end with the corresponding line impedance this is normally 1200hm Strain Gauge Sensitivity Adjustment DSC ONLY For DCell strain gauge sensitivity adjustment please consult factory If your strain gauge does not deliver a 2 5mV V full scale output you may want to adjust the sensitivity of the electronics hardware and or the software gain controls If you want to test with an input of more than 2 5mV V you will have to adjust the
73. onmental Approvals see chapter 15 It Is Advisable To Follow The Following Installation Practice Where Possible e Minimise vibration e Do not mount next to strong electrical or magnetic fields transformers power cables e Install electrical protection device as the unit is not internally fused e Always ensure the package is secure and protected Physical Mounting DCell is normally sealed in the pocket of the load cell which provides mechanical and moisture protection and electrical shielding The DCell should be mounted using a 2mm screw to the body of the load cell This should be a Good electrical connection to obtain maximum performance Connecting wires are soldered directly to the pads on the top and or bottom of the PCB Care must be taken to electrically insulate the connection pads from the surrounding metal DSC is normally installed in a protective enclosure such as a metal box The pins can be plugged into standard 0 1 pitch PCB header sockets or soldered directly into a host board or to connecting wires It can be mounted either way up Unwanted pins projecting on one side may be cropped off For extra vibration resistance the 3 mounting holes provided can be used If not required the protruding end with the single hole can be cut off to make the board smaller Electrical Protection No additional electrical shielding is normally needed Electrostatic protection is sufficient for installation purposes on
74. onnected to a supply set between 5 6v and 18v DC The red wire being positive and the black negative The CAN is connected using the 9 way D type extension lead to J3 and to the USB CAN converter Ensure LK1 amp LK5 are set to CAN RS485 Fit LK2 which terminates the CAN bus Switch on the Green Power LED of the DSJ1 should be on Initial Checks With no load cell connected The LED of the DCell or DSC should flash OFF for 100ms every 0 5s Note If a Load cell is connected and there are no errors then the LED will Flash ON for 100mS then Off for the above period This being the normal healthy state Another check that the device is working okay is by noting the current drawn from the supply this should be about 40mA Instrument Explorer Instrument Explorer is Mantracourts own communication interface for our range of standard products It provides communications drivers for the DCell DSC products A complimentary copy is provided on CD ROM with the DCell DSC Evaluation Kit Instrument Explorer can also be downloaded from Mantracourts website http www mantracourt co uk software Instrument_Explorer Instrument Explorer is a software application that enables communication with Mantracourt Electronics instrumentation for configuration calibration acquisition and testing purposes The clean contemporary interface allows full customisation to enable your Instrument Explorer to be moulded to your individual requirements What Ca
75. ons and power supply bus cable DCell Bus End Arrangement Note The specified cable above shows a EMC Gland yellow wire this will be replaced with a white wire M2 screw to metal body f i 2 x Twisted Pair Note shield terminated at EMC gland using 360 termination Body is Grounded Key Requirements The cable must enter the load cell via an EMC cable gland which connects the cable shield to the load cell body This must be a 360 Degree connection The cable should be a twin twisted pair with independent shields with one pair used for the communications and the other for the power wires There MUST be a common connection from the PSU and the CAN ground to ensure the CAN stays within the required common mode voltage of 2v CANL to 7v CANH The shield should be connected to the grounded enclosure of the power supply 53 Mantracourt Electronics Limited DCell DSC CANopen User Manual DSC4 Versions Power and Communications Wiring The following diagram illustrates how to connect a DSC4 card to the communications and power supply bus cable DSC4 Versions Bus End Arrangement Y e or tv Boo go S CANH Ts i A r CANH CANL CANGND Note The specified cable above shows a yellow wire this will be replaced with a white wire Key Requirements The cable should be a twin twisted pair with independent shields with one pair used for the communications and the other for the power
76. ory calibrated output in mV V units e ELEC is the mV V in terms Where the 100 value is set using NMMV This is for backwards compatibility only e TEMP is a device temperature measurement in C and requires an optional module There are also two flags ECOMUR and ECOMOR not shown on the diagram which indicate an input electrical under or over range Cell The Cell calibration converts the mV V output into a cell force reading 29 Mantracourt Electronics Limited DCell DSC CANopen User Manual This can be used by an OEM sensor manufacturer to provide a standard calibrated output in force units which could be based on either typical or device specific calibration data This stage also includes the temperature and linearity corrections not covered here The outputs from this are e CMVV is the temperature compensated mV V MVV e CRAW is the scaled temperature compensated value CMVV e CELL is a load cell force reading in Force units e g kN e CRAWUR and CRAWOR are two flags indicating under or over range for the force measurement System The System calibration converts the Cell output into a final output value in the required engineering units This is normally be set up by a systems installer or end user to provide whatever kind of output is needed independently of device specific information in the Cell calibration Making this split allows in service replacement without re calibration The
77. ough 1 0 0 0 100 0 100 0 SZ 0 0 SNAP Click to execute Peak Trough RSPT Click to execute Dynamic values such as SYS and SRAW will now be updating in real time from the device Once you have connected the load cell you should see believable output values in the SYS parameter displayed in the parameter list pane These values should correspond to mV V assuming the device is in it s factory default state Mantracourt Electronics Limited DCell amp DSC CANopen User Manual 14 For diagnostics the device has a of flags Which is dynamic and will cause an Emergency Telegram to be broadcast on change of state Performing A System Calibration The values obtained so far are in mV V units these are factory calibrated and fixed to within about 0 1 accuracy The device also contains two separate user adjustable calibration parameter groups these are termed Cell and System Cell being used to convert from mV V to a force and System to convert this force to required engineering units We shall being using System for the following exercise where we rescale the output value to read in units of your choice and to calibrate precisely to your load cell system hardware Instrument Explorer provide Wizards to allow quick and simple calibration operations to be undertaken without the use of a calculator Wizards can be activated by simply selecting the required item from the Wizard menu Since w
78. ow input level Enter required value for SYS 0 01573 0 Click the Next button and enter the high values as shown below A SYS Calibration Table Enter High Data Enter the high level input value and required output value Enter value for CELL at this high input level Enter required value for SYS 219053 Click Next the following window will be displayed showing the calibrated SYS value which is dependent on the current input values SYS Calibration Table Result Instrument calibration complete The new calibration values have been calculated and the instrument updated Click Finish to complete this Wizard The display below shows the value of SYS You can now apply the low and high inputs to check that the calibration was successful You can press the Back button to return to a previous calibration stage to repeat it SYS 5 514293 NOTE Some instruments have parameters that clamp the output values If the SYS output seems incorrect you should first check the instrument manual to see if there are any parameters that can clamp this output The device is now calibrated However you may find SYS has been clamped if the resultant SYS is greater than SMAX or less than SMIN If this is the case then change these values to suitable limits In this example we may set SMIN to 0 5 tonne and SMAX to 12 0 tonne This would then provide clamping of SYS to these values and also a flags being set in FLAG and STAT
79. r American equivalent 0 80 Important Note DO NOT USE 2 screw size DCell CAN viewed from LED side Hole centre positions taken from pcb centre a All dimensions are in mm 1st layer x y Hole diameter OS at Mounting Hole Mounting hole 0 0 8 1 2 0 V 3 2 7 9 1 0 EXC WV 5 4 6 6 1 0 SIG CAN L 8 0 1 7 1 0 Red LED gt CANL CAN H 8 2 3 0 1 0 is o O yp X Temp sensor DQ 7 1 5 0 1 0 CANE EXC 7 5 4 9 0 7 e SIG 88 15 07 Temp Sensor DQ SIG 8 0 3 9 0 7 EXC 6 3 6 1 0 7 CE Approvals European EMC Directive 2004 108 EC BS EN 61326 1 2006 BS EN 61326 2 3 2006 Mantracourt Electronics Limited DCell DSC CANopen User Manual 62 Warranty All DCell amp DSC products from Mantracourt Electronics Ltd Mantracourt are warranted against defective material and workmanship for a period of 3 three years from the date of dispatch If the Mantracourt product you purchase appears to have a defect in material or workmanship or fails during normal use within the period please contact your Distributor who will assist you in resolving the problem If it is necessary to return the product to Mantracourt please include a note stating name company address phone number and a detailed description of the problem Also please indicate if it is a warranty repair The sender is responsible for shipping charges freight insurance and proper packaging to prevent breaka
80. rt time Warning flags survive power down i e they are backed up in non volatile EEPROM storage Though useful this means that repeatedly cancelling errors which then shortly recur can wear out the device non volatile storage see Chapter 3 Basic Set up and Calibration Meaning and Operation of Flags The various bits in the FLAG value are as follows Bit Value 6 KR Wl rNm AJN Description Name a u 32 64 NX 11 2048 00 Strain gauge input over range ECOMOR Cell under range CRAW CRAWUR 12 4096 11 8192 14 16384 15 32768 NOTE The mnemonic names are used by convenience properties in Instrument Explorer but are otherwise for reference Load Cell Integrity Error LCINTEG LCINTEG Watchdog Reset WDRST unused reserved BRWNOUT Reboot warning Normal Power up REBOOT only the flags can only be accessed via the FLAG parameter The various warning flags have the following meanings TEMPUR and TEMPOR indicate temperature under and over range The temperature minimum and maximum settings are part of the temperature calibration fixed at 50 0 and 90 0 C Only active when optional Temperature module fitted ECOMUR and ECOMOR are the basic electrical output range warnings These are tripped when the electrical reading goes outside fixed 120 limits This indicates a possible overload of the input circuitry i e the input is too big to measure The tested value
81. s 40 000 Counts divs Resolution 100Hz readings Noise stable over 100s 10 000 Counts divs Signal Filter Dynamic recursive type user programmable Oooo o Optional Temperature Resolution T O Temperature Measurement Resolution 0 0625 Degc Temperature Measurement Accuracy 10 to 85 05s Degc Temperature Measurement Accuracy 55 to 125 2 0 Deg C Temperature update Speed 5 Seconds Electrical o EA idge D 100 mV ac pk pk Power E 10v 350R Bridge 450 Environmental Output Data terminal Output cable length speed dependant Note 3 O 6 20K perating temperature range 40 PCB Dimensions DSC 87 4 x 20 x 8 5mm PCB Dimensions DCell Diameter 20mm Height 10mm Notes 1 From original offset at any time 2 1st Year 3 Dependent on cable type and bit rate The DSC digital output is an open collector transistor rated at 100mA 40v 61 Mantracourt Electronics Limited DCell DSC CANopen User Manual Mechanical Specification for DSC Note Viewed from top side CAN label as photo on front cover of manual TTT 87 4mm 80 9mm HOLES 0 9mm x15 2 We el T n r E E 7 f N fi legts a RL 2 ji Ex ii E A O 5 Ros Na N R3 0 A j3 4mm 7 3mm lt 78 4mm 3897 BFL Mechanical Specification for DCell DCell Diameter 20mm Height 10mm and has an 2mm mounting hole to accept M2 screw o
82. set MVV is mV V force is force units and eng is engineering units Mantracourt Electronics Limited DCell amp DSC CANopen User Manual 30 Calibration Parameters Summary and Defaults The various control parameters are listed for each stage This also includes the compensation parameters not covered in this chapter but shown in the flow diagram The default values shown set the device back to its nominal default calibration mV V Cell Control Defaults Command Action Default Values FFLV Filter dynamic level 0 001 FFST Filter Steps max 100 NMMV Nominal 2 5mV V 2 5 RATE Rate 10Hz 3 CGAI basic cell gain 1 0 COFS basic cell offset 0 0 CTN number of temp points 0 CT1 5 temp points Deg C 0 0 0 0 0 0 CTO1 5 offset adjusts 0 0 0 0 0 0 CTG1 5 gain adjusts 1 0 1 0 1 0 1 0 CMIN CRAW min limit 3 0 CMAX CRAW max limit 3 0 CLN number of linearity points 0 CLX1 7 linearity raw value points 0 0 0 0 0 0 CLK1 7 linearity adjusts 0 0 0 0 0 0 System Control Defaults Command Action Default Values SGAI basic gain 1 0 SOFS basic offset 0 0 SMIN SRAW min limit 100 0 SMAX SRAW max limit 100 0 SZ output zero offset 0 0 31 Mantracourt Electronics Limited DCell DSC CANopen User Manual Chapter 5 Temperature Compensation This chapter explains how to use the Temperature Compensation facilities to compensate for changes in the measurement with am
83. temperature effects from distorting the results The linearisation tests should not reveal any significant remaining linear trend in the errors If errors do appear to lie on a definite line this could drastically reduce the accuracy of the correction If this does happen it shows that the cell calibration is wrong and should be redone The table points must always cover more or less the whole range of output values to be used because corrections are extrapolated outward beyond the first and last points It is always worthwhile including more test points than will be used in the correction table because this gives confidence that no regions of rapidly changing error have been missed Tests should be done both with steadily increasing and decreasing load values as hysteresis effects for load cells are often of a similar size to non linearities Parameter Calculations and Example Based on the simple method outlined above we suppose that we have obtained test results for a series of precisely known load values test loads Xj give readings of CRAW Cj for i 1 n Then calculate the errors that need to be removed at these points Ej Xj Cj Now just enter these values into the correction table remembering to scale the errors CLN n CLX X CLKj 1000 e Ej Example Suppose we have a load cell and Cell calibration giving a result in the range 0 500 KgF The following test results were obtained using a series of known t
84. the data fast enough 27 Mantracourt Electronics Limited DCell DSC CANopen User Manual User Storage USR1 USR9 There are nine storage locations USR1 to USR9 These are floating point numbers which can be used for storage of data This data could be calibration time and date operator number customer number etc This data is not used in anyway by the DCell or DSC Reset The Reset command RST This command is used to reset the device This command MUST be issued if the following parameters are changed before the change will take effect Alternatively the power maybe cycled RATE NODEIDL NODEIDH BPS and all of the Message parameters The reset action may take up to about a second to take effect followed by the normal start up pause of 1 second WARNING Finite Non Volatile Memory Life The DCell and DSC use EEPROM type memory as the storage for non volatile controls i e all the settings that are retained even when powered down The device EEPROM itself is specified for 100 000 write cycles for any one storage location although typically this is 1 000 000 Therefore When automatic procedures may write to stored control parameters it is important to make sure this does not happen too frequently So you should not for example on a regular basis adjust an offset calibration parameter to zero the output value However it is reasonable to use this if the zeroing process is initiated by the operator and won t normal
85. then be RG 1 0 025 rqd m V V 0 01 Two effects should be noted 1 The purpose of increasing sensitivity is to reduce reading noise which governs the effective resolution Using software gain alone obviously gives reduced performance 2 The sensitivity should however not be set greater than typically 1mV V Beyond this input noise usually dominates and no extra benefit can be achieved 57 Mantracourt Electronics Limited DCell DSC CANopen User Manual Chapter 11 Troubleshooting This chapter gives a quick guide to problem solving for DCell DSC devices Bear in mind that the quickest way to pin down problems is to usually replace items with known good alternatives This also applies to cables power supplies devices etc LED Indicator The LED is used to indicate the protocol selection the device is powered and the Device is Operating For correct operation the LED should Flash ON for 100mS then repeat at a rate depending on the protocol See table below If this is not the case then follow the instructions below If the LED is OFF check the power supply polarity amp voltage The voltage including any troughs should be above 5 6V and less than 18V If the supply polarity and voltage is correct then switch off remove the strain gauge from circuit and switch on If the LED is still off check the current drawn by the device With no strain gauges should be approx 30mA If the LED is permanently ON then conta
86. tus 2 Digital Input status DSC ONLY IPSTAT Cell under range CRAW 128 Cell over range CRAW CRAWOR 11 2048 Load Cell Integrity Error LCINTEG LCINTEG 12 4096 Shunt Calibration Resistor ON SCALON 11 14 16384 unused reserved 15 32768 unused reserved Wwini O ajA 6 64 7 oo SPSTAT indicates the state of the Open collector output 1 being output on 0 being output off IPSTAT indicates the state of the digital input Only available on DSC model Bit set indicates input is closed to Ov V or GND SCALON Used to indicate that the Shunt Calibration command SCON has been issued amp therefore the shuntcal resistor is now in circuit with the strain gauge bridge SCOF command resets this bit Note that when Shunt Calibration is active the Load Cell Integrity Error will also be generated OLDVAL is set when the device is read via the communications Thus indicating this value has already been sampled It is reset when a new result has been made available Output Update Tracking The OLDVAL flag can be used for output update tracking This allows sampling each result exactly once To achieve this poll the STAT value until OLDVAL is cleared to indicate a new output is ready then read SYS this reading will set the OLDVAL flag in STAT This scheme works as long as the communications speed is fast enough to keep up With faster update rates and slower baud rates it may not be possible to read out
87. ve eek how a Rs di A iaa 9 Running the Instrument Explorer SOFtWALE ccc cece ence eee ences eee e eee e ence ene non r cnn sense eneeeeneeeeseeeeeenseeeeeeeaees 10 Instrument Explorer COM s mesic crievies reiii ii Po Ri dE EEEE EEVEE alte saad A NEEE EES E 10 Instrument Settings seson sneri ia A A nedeead ncvadeaeds 11 Viewing Device Dating ir A A A A erodes ibas 12 Instrument Explorer Parameter List ccccccescecsceesceesceesseeeeeeeeseenseeeseeaeeeeseesseeeaseseseeeseeesesseeeaseeaees 12 Gonnecting a Load Cell esi anren etait Sasa baie Raa vg Bey n A aa 13 DSJ1 Evaluation Board Sensor Connections cceeeeee eee eee ese e eee nc ence nee ne ence ee ene eee eee ence eeeeeeenseneeneeeseeeeees 14 Performing A System Calibration ccccc cece cece ence ence ee ee ence ene eens eens eens eee eens eens ee eeeeeeseeneeeeeeeeseeeeeeeaees 15 Chapter 3 Explanation of Category Items cccceccescsscscccsccsccscessscescesscensensseescescescssassessesessenseeees 19 Informationer eenaa E A e A A AS Syed eee dha teed Oe aadened ERNE Maat 19 Software Version VER ii okie Sov coed Sa a Sou Ne hie a ee AA A A MOE R aes we Eee Mees Se AA 19 Serial Number SER and SERA rne e ones 5 ak 2o coe Saad ashen a ETEA OERE 19 STEAM GA A dete snus canes dum reeds A Aa 19 MV AV OULBUE MVVissncseniesesvecetcebdxencens nr REA ea ess ES tebe sand NASA LAA AAA AAA EERE 19 Nominal mV Vilevel NM VV asia A E ae E SEA EE ane gee RREA 19
88. will not take effect until the unit is power cycled On receiving a NMT Reset_Node or Reset_Communication service all the device independent communications settings revert to the CANopen standard default settings The Node ID and Bit Rate are not reset by this Mantracourt Electronics Limited DCell DSC CANopen User Manual 42 Data Type Conversions and Rounding Type Conversion Depending on the protocol an integer byte parameter may need to be converted to or from a floating point representation for reading or writing The rules are as follows For reading integer and byte parameters are treated as unsigned and never read negative i e read value ranges are 0 to 65535 0 and 0 to 255 0 For writing values written to integer and byte parameters are truncated to the nearest integer and negative or positive values are acceptable NOTE Floating point data is not always exact even when reading integral data e g could get 3 999974 instead of 4 e g for a byte write 240 240 1 and 239 66 are all the same value Rounding Although rounding is applied when writing to integral values data read from a device is not rounded off 43 Mantracourt Electronics Limited DCell DSC CANopen User Manual Chapter 9 Object Dictionary This chapter contains tables of all DCell DSC Object Dictionary with brief details of each Communications Profile Area Device Description and Communication Specific Name Description
89. wires The cable shield must be grounded to the SH pin at the DSC end and not at the host end Any further metal housing should also be grounded to the DSC pin and should not be connected to the bus cable shield or the sensor cable There MUST be a common connection from the PSU and the CAN ground to ensure the CAN stays within the required common mode voltage of 2v CANL to 7v CANH Suitable Cable Types DCell DSC CAN Bus Cable The Cable requirements are dependent on the bit rate of the CAN bus and the required distances Special care is required for bit rates of over 500Kbps not only in the choice of cable used but how the bus wiring is organised ie the requirement for very small stub lengths for high bit rates For low bit rates the requirements can be specified as follows A suitable type is BICC Brand Rex BE56723 also equivalent to Belden type 8723 In the UK this is available from Farnell part number 118 2117 For bit rates above 500Kbps the following is recommended Belden B3084A Belden B8132 Mantracourt Electronics Limited DCell amp DSC CANopen User Manual 54 CAN Bus Connections for Multiple DCells di aaa lariat loa r a EMC Gland s 360 Terminating m e o foo Terminating Resistor 120R Terminating f 4 Resistor
90. wisted cable should be used although standard 4 core shield cable can be used in low noise environments The M2 mounting hole must be grounded via an M2 screw to the load cell body for specified performance to be met The 2mm mounting hole to accept M2 screw or American equivalent 0 80 Important Note DO NOT USE 2 screw size 51 Mantracourt Electronics Limited DCell DSC CANopen User Manual DSC Strain Gauge Cabling Arrangement EMC Gland Note shield terminated at EMC gland using 360 termination Tail length must be kept to a mimimum Key Requirements The Strain Gauge cable should be a twin twisted pair with independent shields with the two pairs used for the EXC and SIG signal pairs For specified performance the load cell must be grounded to the SH DSC Sensor Cable require 2 x twisted pair version otherwise similar to the above A suitable type is BICC Brand Rex PD3003 also equivalent to Belden type 8777 In the UK this is available from Farnell enter Belden 8777 for real length options Mantracourt Electronics Limited DCell DSC CANopen User Manual 52 Communications Cabling and Grounding Requirements To achieve full performance specifications and conform to environmental approvals it is important to follow the wiring procedures outlined in this section DCell Power and Communications Wiring The following diagram illustrates how to connect a puck to the communicati

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DCell & DSC Strain Gauge or Load Cell Embedded