USB-2408 Series User's Guide
Contents
1. 19 USB 2408 Series User s Guide Functional Details J6 47 KO Internal jumper disabled placed on center pin only Counter input V External pull up resistor DIOO DIO1 DIO2 DIO3 DIO4 DIO5 DIOG DIO7 Figure 14 Digital I O external resistor configuration The CTRO and CTR1 terminals are 32 bit event counters that can accept frequency inputs up to 1 MHz The internal counter increments when the TTL levels transition from low to high Ground The analog ground AGND terminals provide a common ground for all analog channels The digital ground GND terminals provide a common ground for the digital and counter channels and the power terminal 20 USB 2408 Series User s Guide Functional Details Mechanical drawings MDOODODODOOO O pessed pss passed jpoooos J 200000 wooo ooo 0009009 Figure 15 USB 2408 Series device circuit board top and enclosure dimensions 21 Chapter 4 Specifications All specifications are subject to change without notice Typical for 25 C unless otherwise specified All specifications apply to all temperature and voltage input channels unless otherwise specified Specifications in italic text are guaranteed by design Analog input Table 1 General analog input specifications Parameter Conditions Sp2. where n is the number of channels gt eer 640 us data rate Table 12 Multiple channel throughput rate specifications Hz Number of input channels 3750 S s 2000 S s 1000 S s 500 S s 100 S s 60 S s 50 S s 25 S s 10 S s 5S s 2 5S s 1 1102 94 877 19 609 76 378 79 93 98 57 78 4845 24 61 9 94 4 98 2 50 2 551 47 438 60 304 88 189 39 46 99 28 89 2422 1230 4 97 249 1 25 3 367 65 292 40 203 25 126 26 31 33 19 26 16 15 8 20 3 31 1 66 0 83 4 275 74 219 30 152 44 94 70 23 50 14 45 12 11 6 15 2 48 1 25 0 62 5 220 59 175 44 121 95 75 76 18 80 11 56 9 69 4 92 1 99 1 00 0 50 6 183 82 146 20 101 63 63 13 15 66 9 63 8 07 4 10 1 66 0 83 0 42 7 157 56 125 31 87 11 54 11 13 43 8 25 6 92 3 52 1 42 0 71 0 36 8 137 87 109 65 76 22 47 35 11 75 7 22 6 06 3 08 1 24 0 62 0 31 9 122 55 97 47 67 75 42 09 10 44 6 42 5 38 2 73 1 10 0 55 0 28 10 110 29 87 72 60 98 37 88 9 40 5 78 4 84 2 46 0 99 0 50 0 25 11 100 27 79 74 55 43 34 44 8 54 35 25 4 40 2 24 0 90 0 45 0 23 12 91 91 73 10 50 81 31 57 7 83 4 82 4 04 2 05 0 83 0 42 0 21 13 84 84 67 48 46 90 29 14 7 23 4 44 3 73 1 89 0 76 0 38 0 19 14 78 78 62 66 43 55 27 06 6 71 4 13 3 46 1 76 0 71 0 36 0 18 15 73 53 58 48 40 65 23 25 6 27 3 85 3 23 1 64 0 66 0 33 0 17 16 68 93 54 82 38 11 23 67 5 87 3 61 3 03 1 54 0 62 0 31 0 16 Analog voltage output USB 2408 2AO only
3. USB specifiCationgz3 ii AAT Vbi natem inet Ule m 31 Environmental Mechanical Sranan Screw terminal connector type and pinout annae snevenv enne enneenneenseenseenvensersnenseensvenneenneenneensenneennevensenn 31 Screw terminal pinout Declaration of Conformity erroan aE EA IAA A RA A ANAA I ARA E 34 Preface About this User s Guide What you will learn from this user s guide This user s guide describes the Measurement Computing USB 2408 Series data acquisition devices and lists device specifications Conventions in this user s guide For more information about Text presented in a box signifies additional information and helpful hints related to the subject matter you are reading Caution Shaded caution statements present information to help you avoid injuring yourself and others damaging your hardware or losing your data bold text Bold text is used for the names of objects on a screen such as buttons text boxes and check boxes italic text Italic text is used for the names of manuals and help topic titles and to emphasize a word or phrase Where to find more information Additional information about USB 2408 Series hardware is available on our website at www mccdag com You can also contact Measurement Computing Corporation by phone fax or email with specific questions Phone 508 946 5100 and follow the in
4. Multi channel 1000 S s ch max system dependent Table 14 Calibrated absolute accuracy specifications Range Accuracy tL SB 10 V 16 0 Table 15 Calibrated absolute accuracy components specifications Range of reading Offset EmV Temp drift C Absolute accuracy at FS tmV 10 V 0 0183 1 831 0 00055 3 661 Table 16 Relative accuracy specifications Range Relative accuracy LSB 10 V 4 0 typ Analog input output calibration Table 17 Analog input output calibration specifications Parameter Specifications Recommended warm up time 45 minutes min Calibration Firmware calibration Calibration interval 1 year Al calibration reference 10 000 V 5 mV max Actual measured values stored in EEPROM Tempco 5 ppm C max Long term stability 30 ppm 1000 hours AO calibration procedure The analog output pin is internally routed to the analog input pin USB 2408 2A0 only AOUTx readback Each AOUTx output can be independently measured by the onboard A D converter USB 2408 2A0 only Software selectable 28 USB 2408 Series User s Guide Specifications Digital input output Table 18 Digital input specifications Parameter Specifications Number of I O 8 channels Configuration Each DIO bit can be independently read from DIN or written to DOUT The DIN bits can be read at any time w
5. The USB 2408 Series device screw terminals provide the following connections 16 SE CHO to CH15 see Figure 4 or eight DIFF CHOH CHOL to CH7H CH7L analog input connections Eight digital I O connections DI00 to DI07 Two analog output connections AOUTO AOUT1 USB 2408 240 only Two counter inputs CTRO CTR1 One power output 5V 10 analog grounds AGND four digital grounds DGND and one chassis ground CHAS Al channel 0 CHO 1 Analog ground Al channel 8 CH8 2 amp Al channel 15 Analog ground AGND 3 e Al channel 7 Al channel 1 CH1 4 amp Analog ground Al channel 9 CH9 5 Al channel 14 Analog ground AGND 6 Al channel 6 Al channel 2 CH2 7 Analog ground Al channel 10 CH10 8 Al channel 13 Analog ground AGND 9 Al channel 5 Al channel 3 CH3 10 Analog ground Al channel 11 CH11 11 Al channel 12 Analog ground AGND 12 Al channel 4 Analog ground AO channel 1 Analog ground Digital ground DGND 13 AO channel 0 DIOchannel0 DIOO 14 8 DIO channel 1 DIO1 15 16 DIO channel 2 DIO2 16 DIO channel 3 DIO3 17 Chassis ground DIO channel 4 DIO4 18 5 V user output DIO channel 5 DIOS 19 Q Digital ground DIO channel 6 DIO6 20 Counter channel 1 DIO channel 7 DIO7 21 18 Digital ground Digital ground DGND 22 Counter channel 0 Figure 4 SE mode pin out These pins are labeled NC no connection on the USB 2408 12 USB 2408 Series User s Guide Functional Deta
6. 2 28 1 39 1 04 0 65 0 63 0 60 0 54 0 35 0 32 0 36 25 USB 2408 Series User s Guide Specifications Table 9 Noise free resolution specifications bits A D data rate Range 3750 S s 2000S s 1000S s 500S s 100S s 60S s 50S s 25S s 10S s 5S s 2 5S s 10 V 17 2 17 6 18 1 18 7 19 3 19 3 19 5 20 0 20 6 21 0 21 0 5 V 17 4 17 6 18 1 18 5 19 2 19 4 19 4 19 4 20 6 21 0 21 0 2 5 V 17 2 17 4 18 1 18 4 19 3 19 4 19 4 19 7 20 3 20 7 21 0 1 25 V 17 0 17 1 17 4 18 0 18 8 18 8 18 9 19 3 19 5 19 5 19 7 0 625 V 16 0 16 2 17 1 17 3 17 8 18 0 18 1 18 3 18 9 18 8 19 2 0 3125 V 15 3 15 3 16 2 16 4 17 0 17 0 17 0 17 3 17 5 17 9 17 9 0 15625 V 14 5 14 1 15 3 15 5 15 7 16 1 16 1 16 1 16 8 16 9 17 1 0 078125 V 14 5 14 3 15 0 15 4 16 1 16 2 16 2 16 4 17 0 17 1 16 9 Channel switching error Table 10 Step response accuracy specifications Accuracy Range 3750 S s 2000 S s 1000 S s 500S s 100S s 60S s 50S s 25S s 10S s 5S s 2 5 Sis 10 V 0 0010 0 0008 0 0005 0 0004 0 0002 0 0002 0 0003 0 0002 0 0001 0 0001 0 0001 5 V 0 0009 0 0008 0 0004 0 0004 0 0003 0 0002 0 0002 0 0002 0 0001 10 000196 0 0001 2 5 V 0 001096 0 0007 0 0008 0 0004 0 0003 0 0002 0 0002 0 0002 0 0002 0 0001 0 0001 1 25 V 0 0013 0 0009 0 0008 0 00
7. Counter 1 21 DIO7 Digital input output 43 DGND Digital ground 22 DGND Digital ground 44 CTRO Counter 0 Note 10 On the USB 2408 these pins are labeled NC no connection 33 CE Declaration of Conformity Manufacturer Measurement Computing Corporation Address 10 Commerce Way Suite 1008 Norton MA 02766 USA Category Electrical equipment for measurement control and laboratory use Measurement Computing Corporation declares under sole responsibility that the products USB 2408 Series to which this declaration relates is in conformity with the relevant provisions of the following standards or other documents EC EMC Directive 2004 108 EC General Requirements EN 61326 1 2006 IEC 61326 1 2005 Emissions EN 55011 2007 CISPR 11 2003 Radiated emissions Group 1 Class A EN 55011 2007 CISPR 11 2003 Conducted emissions Group 1 Class A Immunity EN 61326 1 2006 Table 3 EC 61000 4 2 2001 Electrostatic Discharge immunity EC 61000 4 3 2002 Radiated Electromagnetic Field immunity To maintain compliance to the standards of this declaration the following conditions must be met The host computer peripheral equipment power sources and expansion hardware must be CE compliant All I O cables must be shielded with the shields connected to ground I O cables must be less than 3 meters 9 75 feet in length The host computer must be properly grounded The host computer must be
8. Measurement Computing Corporation immediately by phone fax or e mail Phone 508 946 5100 and follow the instructions for reaching Tech Support Fax 508 946 9500 to the attention of Tech Support Email techsupport mccdaq com For international customers contact your local distributor Refer to the International Distributors section on our web site at www mccdag com contact2 aspx USB 2408 Series User s Guide Installing a USB 2408 Series Device Installing the software Note Before installing a USB 2408 Series device you must install the software you plan to use with the device The USB 2408 Series is supported by DAQFlex software and Universal Library and InstaCal software You can install both software packages on your computer However you cannot run both software packages simultaneously with one USB 2408 Series device DAQFlex Install DAQFlex software when you want to develop data acquisition applications that can be deployed across multiple operating systems and custom embedded systems DAQFlex software for each supported operating system is available from the DAQFlex download page at www mecdag com DAQFlexDL Refer to the DAQFlex Software User s Guide at www mecdag com pdfs manuals DAQFlex 20Software pdf for instructions about installing DAQFlex software Universal Library and InstaCal Install Universal Library and InstaCal when you want to develop data acquisition applications using Windows programming l
9. USB 2 0 compliant Equipment must be operated in a controlled electromagnetic environment as defined by Standards EN 61326 1 2006 or IEC 61326 1 2005 Note Data acquisition equipment may exhibit noise or increased offsets when exposed to high RF fields gt 1V m or transients Declaration of Conformity based on tests conducted by Chomerics Test Services Woburn MA 01801 USA in November 2010 Test records are outlined in Chomerics Test Report EMI5755 10 We hereby declare that the equipment specified conforms to the above Directives and Standards Loupe Carl Haapaoja Director of Quality Assurance Measurement Computing Corporation 10 Commerce Way Suite 1008 Norton Massachusetts 02766 508 946 5100 Fax 508 946 9500 E mail info mccdag com www mccdag com
10. Unused AOUTx output channels should be left disconnected The USB 2408 2A0 output voltage level defaults to 0 V whenever the host PC is reset shut down or suspended or if a reset command is issued to the device The outputs may have a transient during startup The duration of the output transient depends highly on the enumeration process of the host PC Typically the output of the USB 2408 2A0 is stable after two seconds Table 13 USB 2408 2A0 analog voltage output specifications Parameter Conditions Specifications Digital to analog DAC8552 converter Number of channels 2 Resolution 16 bits Output ranges Calibrated 10 V Uncalibrated 10 05 V software selectable Output transient Host PC is reset powered on suspended or a reset Duration 2 s command is issued to device Amplitude 2 V p p Initial power on Duration 50 ms Amplitude 5 V peak Differential non linearity 0 25 LSB typ 1 LSB max Output current AOUTx pins 5 0 mA max Output short circuit AOUTx connected to AGND Unlimited duration protection 27 USB 2408 Series User s Guide Specifications Parameter Conditions Specifications Output coupling DC Power on and reset state DACs cleared to zero scale 0 V 50 mV Output noise 60 HV ns BW 1 5 KHz Settling time To rated accuracy 10 V step 75 HS Slew rate 1 0 V us Throughput Single channel 1000 S s max system dependent
11. 0 non condensing max Mechanical Table 26 Mechanical specifications Parameter Specifications Dimensions L x W x H 127 x 89 9 x 35 6 mm 5 00 x 3 53 x 1 40 in User connection length 3 meters max Screw terminal connector type and pinout Table 27 Screw terminal connector specifications Connector type Fixed screw terminal Wire gauge range 16 AWG to 30 AWG 31 USB 2408 Series User s Guide Specifications Screw terminal pinout Table 28 8 channel differential mode pinout Pin Signal name Pin description Pin Signal name Pin description 1 CHOH Channel 0 HI 23 AGND Analog ground 2 CHOL Channel 0 LO 24 CH7L Channel 7 LO 3 AGND Analog ground 25 CH7H Channel 7 HI 4 CH1H Channel 1 HI 26 AGND Analog ground 5 CH1L Channel 1 LO 27 CH6L Channel 6 LO 6 AGND Analog ground 28 CH6H Channel 6 HI 7 CH2H Channel 2 HI 29 AGND Analog ground 8 CH2L Channel 2 LO 30 CH5L Channel 5 LO 9 AGND Analog ground 31 CH5H Channel 5 HI 10 CH3H Channel 3 HI 32 AGND Analog ground 11 CH3L Channel 3 LO 33 CH4L Channel 4 LO 12 AGND Analog ground 34 CH4H Channel 4 HI 13 DGND Digital ground 35 AGND Analog ground 14 DIOO Digital input output 36 AOUT1 Note 9 Analog output 1 15 DIO1 Digital input output 37 AGND Analog ground 16 DIO2 Digital input output 38 AOUTO Note 9 Analog output 0 17 DIO3 Digital input out
12. 07 0 0004 0 0004 0 0003 0 0003 0 0003 0 0003 0 0003 0 625 V 0 0022 0 0016 0 001 1 0 001 1 0 00079 0 0007 0 0005 0 0005 0 0004 0 0005 0 0003 0 3125 V 0 003 1 0 003 1 0 0020 0 0017 0 00157 0 0012 0 0010 0 0010 0 0012 0 0009 0 0009 0 15625 V 10 005696 0 0062 0 0048 0 0037 0 0032 0 0025 0 0024 0 0021 0 0019 0 0022 0 0016 0 078125 V 0 0114 0 012396 0 0076 0 0070 0 0041 0 005 1 0 00469 0 0036 0 0032 0 0030 0 0034 Channel switching error is defined as the accuracy that can be expected after one conversion when switching from a channel with a DC input at one extreme of full scale to another channel with a DC input at the other extreme of full scale expressed in terms of percentage of full scale value Throughput rate The single channel throughput rate is calculated using this formula 1 Maximum throughput z 640 us data rate Table 11 Single channel throughput rate specifications AID data rate Maximum throughput Hz 3750 S s 1102 94 2000 S s 877 19 1000 S s 609 76 500 S s 378 79 100 S s 93 98 60 S s 57 78 50 S s 48 45 25 S s 24 61 10 S s 9 94 5 S s 4 98 2 5 S s 2 50 26 USB 2408 Series User s Guide Specifications The multiple channel throughput rate is calculated using this formula 1 Maximum throughput
13. 2408 Series User s Guide Functional Details You do not need to use ground referencing resistors for TC inputs because the analog front end circuit level shifts the TC output into the common mode input range of the A D USB 2408 Series devices also provide an open TC detection feature for each of the analog input channels configured for TC measurement This feature is enabled or disabled by software and when enabled it detects if an open circuit condition exists at the TC sensor USB 2408 Series devices provide electrostatic discharge ESD protection for each of the TC inputs However before handling TC sensors follow standard ESD practices and discharge any accumulated ESD charge Once the TC sensor is connected to the device the configuration options have been selected and the recommended 45 minute warm up has elapsed the device is ready to make high resolution DIFF temperature measurements Built in cold junction compensation CJC automatically compensates for the additional thermal EMFs generated by connecting the TC leads to the USB 2408 Series device terminal blocks CJC is performed using a high resolution temperature sensor connected close to the device terminal blocks The device includes two separate CJC sensors one on each side of the PCB Software corrects for the additional TCs created at the terminals Once the A D and CJC data is collected the application software uses this data to linearize to an accurate tempera
14. Computing product that is damaged due to misuse or any reason may be eligible for replacement with the same or similar device for 50 of the current list price I O boards face some harsh environments some harsher than the boards are designed to withstand Contact MCC to determine your product s eligibility for this program 30 Day Money Back Guarantee Any Measurement Computing Corporation product may be returned within 30 days of purchase for a full refund of the price paid for the product being returned If you are not satisfied or chose the wrong product by mistake you do not have to keep it These warranties are in lieu of all other warranties expressed or implied including any implied warranty of merchantability or fitness for a particular application The remedies provided herein are the buyer s sole and exclusive remedies Neither Measurement Computing Corporation nor its employees shall be liable for any direct or indirect special incidental or consequential damage arising from the use of its products even if Measurement Computing Corporation has been notified in advance of the possibility of such damages Trademark and Copyright Information Measurement Computing Corporation InstaCal Universal Library and the Measurement Computing logo are either trademarks or registered trademarks of Measurement Computing Corporation Refer to the Copyrights amp Trademarks section on meedag com legal for more information about Measurement Compu
15. USB 2408 Series Multifunction DAQ Devices USB 2408 USB 2408 2A0 User s Guide m ae Fa NN Fa MEASUREMENT r Copyright 2011 AN 94289 COMPUTING Your new Measurement Computing product comes with a fantastic extra Management committed to your satisfaction Refer to www mcedag com execteam html for the names titles and contact information of each key executive at Measurement Computing Thank you for choosing a Measurement Computing product and congratulations You own the finest and you can now enjoy the protection of the most comprehensive warranties and unmatched phone tech support It s the embodiment of our mission To provide data acquisition hardware and software that will save time and save money Simple installations minimize the time between setting up your system and actually making measurements We offer quick and simple access to outstanding live FREE technical support to help integrate MCC products into a DAQ system Limited Lifetime Warranty Most MCC products are covered by a limited lifetime warranty against defects in materials or workmanship for the life of the product to the original purchaser unless otherwise noted Any products found to be defective in material or workmanship will be repaired replaced with same or similar device or refunded at MCC s discretion For specific information please refer to the terms and conditions of sale Harsh Environment Warranty Program Any Measurement
16. anguages Universal Library and InstaCal software are included on the CD that ships with the device Refer to the Quick Start Guide booklet for instructions about installing Universal Library and InstaCal software Installing the hardware Install the software before you install your device A driver needed to run the USB 2408 Series device is installed when you install the software Therefore you need to install the software package you plan to use before you install the hardware For operation on a Windows operating system we recommend that you run Windows Update to update your operating system with the latest USB drivers To connect a USB 2408 Series device to your system turn on your computer and connect the USB cable to an available USB port on the computer or to an external USB hub connected to the computer Connect the other end of the USB cable to the USB connector on the device No external power is required When you connect the device for the first time to a computer running Windows a Found New Hardware dialog opens when the operating system detects the device The dialog closes after the device is installed A green Status LED indicates the device status When the LED is on the device is powered and ready for operation If the LED is not on the device is not powered or did not initialize Figure 2 on page 11 shows the location of the STATUS LED Mac OS X When connecting the device to a computer running t
17. citance relative to AGND as small as possible to avoid settling time and accuracy errors The AGND and DGND pins are isolated from earth ground You can connect thermocouple sensors to voltages referenced to earth ground as long as isolation between the AGND DGND pins and earth ground is maintained 23 USB 2408 Series User s Guide Specifications Table 4 Thermocouple accuracy specifications including CJC measurement error All specifications are Sensor temperature Accuracy error Accuracy error Tempco Thermocouple range maximum typical C C 210 C 2 572 C 1 416 C i 0 C 0 935 C 0 469 C 0 022 1200 C 1 869 C 1 456 C 210 C 2 917 C 1 699 C 0 C 1 017 C 0 526 C 0 029 1372 C 2 478 C 2 022 C 200 C 3 480 C 2 030 C N 0 C 1 201 C 0 659 C 0 029 1300 C 1 991 C 1 600 C 50 C 4 826 C 3 133 C R 250 C 2 117 C 1 424 C 0 082 1768 C 2 842 C 2 347 C 50 C 4 510 C 2 930 Co S 250 C 2 165 C 1 468 C 089 1768 C 3 187 C 2 597 C 250 C 5 489 C 3 956 C B 700 C 2 283 C 1 743 C 0 14 1820 C 2 202 C 1 842 C 200 C 2 413 C 1 352 C E 0 C 1 069 C 0 551 C 0 017 1000 C 1 575 C 1 211 C 200 C 2 821 C 1 676 C T 0 C 1 050 C 0 558 C 0 027 400 C 0 957 C 0 595 C To achieve the thermocouple accuracies listed abo
18. cted to the system bus interface Isolation provides a barrier between the host computer and potentially hazardous voltages by physically and electrically separating two parts of the measurement device The non isolated ground is common to the chassis ground of the computer while the isolated ground is not All analog measurements are made relative to the isolated ground See Figure 6 for details l O connectors USB 2408 2A0 onl rezen AIN TIN Isolation barrier Digital Nom Counters isolated isolator uC V Isolated ground PLF PC ground Figure 6 USB 2408 Series input isolation diagram 13 USB 2408 Series User s Guide Functional Details When making measurements in industrial environments DAQ devices can encounter hazardous voltages transients large common mode voltages and fluctuating ground potentials Any one of these issues can seriously degrade the measurement accuracy of the device and possibly damage the measurement instrument To overcome these issues some DAQ devices provide physical and electrical isolation Some of the benefits of isolation include Safety A DAQ device employing physical and electrical isolation helps to keep high voltages and transients from damaging the system side host computer Ground loops Improper grounding of the signal source that the DAQ device is measuring is one of the most common sources of noise and measurem
19. de 90 dB fm 60 Hz all input ranges ADC resolution 24 bits Crosstalk Adj chan DIFF mode 100 dB Input coupling DC Channel gain queue Up to 64 elements Software selectable channel and range Warm up time 45 minutes min Open thermocouple detect Software selectable for each channel CJC sensor accuracy 15 C to 35 C 0 5 C typ 22 USB 2408 Series User s Guide Specifications 0 C to 55 C 1 0 C max Note 1 Placing a notch of the A D digital filter at 60 Hz setting A D data rate 60 S s 10 S s 5 S s or 2 5 S s further improves the common mode rejection of this frequency Channel configurations When any item is changed the firmware stores channel configurations in the EEPROM of the isolated microcontroller An external application issues commands over the USB to make changes and the configuration is made non volatile through the use of the EEPROM When connecting differential voltage inputs to a floating voltage source provide a DC return path from each voltage input to ground To do this connect a resistor from each input to an AGND pin A value of approximately 100 kQ can be used for most applications Leave unused input channels either floating or tied to AGND For each voltage thermocouple channel configured as differential you essentially lose one single ended channel Keep source impedances as small as possible to avoid settling tim
20. e and accuracy errors Table 2 Channel configurations Channel Category Specification CxH CxL Thermocouple 8 differential channels CxH CxL Voltage 16 individually configurable channels that can be configured as either single ended or CxH CxL Voltage 8 differential Compatible sensors Table 3 Compatible sensor type specifications Parameter Conditions Thermocouple J 210 C to 1200 C K 270 C to 1372 C 50 C to 1768 C 50 C to 1768 C 270 C to 400 C 270 C to 1300 C 270 C to 1000 C B 0 C to 1820 C Accuracy Thermocouple measurement accuracy Thermocouple measurement accuracy specifications include polynomial linearization error cold junction compensation measurement error and are for sample rates up to 60S s These specs are for one year or 3000 operating hours whichever comes first There is a CJC sensor for each terminal block of the module The accuracy listed below assumes the screw terminals are at the same temperature as the CJC sensor The accuracy errors shown do not include the inherent accuracy error of the thermocouple sensor itself Contact your thermocouple supplier for details on the actual thermocouple sensor accuracy limitations Connect thermocouples to the USB 2408 Series device such that they are floating with respect to AGND When configuring thermocouple sensors keep any stray capa
21. ecification A D converter type ADS1256 24 bit Sigma Delta A D data rates 3750 S s 2000 S s 1000 S s 500 S s 100 S s 60 S s 50 S s 25 S s 10 S s 5 S s 2 5 S s Throughput Single channel 2 5 S s to 1102 94 S s software selectable Multiple channels 0 16 S s to 551 47 S s software selectable See Table 11 and Table 12 for details Number of channels 16 single ended or 8 differential software selectable Thermocouples require differential mode For each channel configured as differential you essentially lose two single ended channels Input isolation 500 VDC min between field wiring and USB interface Channel configurations Temperature sensor input software selectable to match sensor type Voltage input Input voltage range Thermocouple mode 0 078125 V Voltage mode Note 1 10 V 5 V x2 5 V 1 25 V 40 625 V 40 3125 V 0 15625 V 40 078125 V software selectable Absolute maximum input voltage CxH CxL relative to GND 22 V max power on 70 V max power off Input impedance 10 MQ power on 390 Q power off Input leakage current 20 nA Input voltage gt 30 V 1 uA max power on off Input capacitance 590 pf Maximum working voltage Voltage mode 10 25 V max signal common mode Common mode rejection Thermocouple mode 110 dB ratio Note 1 fin 60 Hz Voltage mo
22. enneennenennenneenseenneenseensenn 5 Where to find more information en omen seerde nth eti ede e em e RET dende te RH deer IS ER ede eei 5 Chapter 1 Introducing the USB 2408 Series annen san onnnenenennnerenennnerenennseneeennnenneennnenrnennnenvensnennenennnen 6 Overview USB 2408 Series features sisie nnani eene nennen entren nennen araa rennen rre 6 USB 2408 Series block diagram tee ERE RERO DE ens es 7 Chapter 2 Installing a USB 2408 Series Device nnnsns anneer en enaner en ennnerenennneerennnnerenennneereennanreennnenrenennen 8 What comes with voutshipment 2 rosa svereereennenetrensserte cues sebeduacectes e n ERR Ra p re PRECEPIT 8 Hardware Annee heeten Documentation Unpacking Installing the software DAOEIGX Aert nt Arden Bee Se nerds Oe EL eenn Universal Librarysand Insta ales 5 5 eee a amer ae 9 Installing the hardware iiec edet ede e EG e EL IS UG Y e Ee Re ede adden 9 Calibrating RR teet bene tiec em need de iei ees Self calibration Factory calibration ED ons 10 Programming and developing applications une uns ere vennv ener enseenverneesmenseerneneneenneenneenneenseenseenvenseensennten 10 Chapter 3 F nctional Details venten arent icc nti a e reete acct rea wanden ten repa sanne eden dennen dence 11 External components senden dee OE le etende e OU NI DE REPE ROI edet ene ois 11 USB connecto
23. ent inaccuracies Isolation improves the measurement accuracy by physically preventing ground loops Ground loops a common source of noise and error are the results of a measurement system having multiple grounds at different potentials Common mode rejection With isolation a DAQ device can measure small signals in the presence of large common mode voltages Isolation increases the ability of the measurement system to reject common mode voltages The common mode voltage is the signal that is common to both the positive and negative inputs of the measurement device but is not part of the signal to measure Analog TC input Each analog input channel has the following measurement parameters Voltage input range TC type J K T E R S B or N You can select a unique input range or signal type for each channel For example one channel could be used for volts and another for temperature Analog input mode You can configure the analog inputs for SE or DIFF mode The input voltage range is software selectable for 10 V x5 V 22 5 V 1 25 V 0 625 V 0 312 V 0 156 V or 0 078 V With SE mode connect up to 16 inputs to screw terminals CHO to CH15 SE mode requires two wires Connect one wire to the signal you want to measure CHx Connect one wire to the analog ground reference AGND Refer to Figure 4 on page 12 for the location of the SE inputs With DIFF mode connect up to eight dif
24. er DIOX ESD protection Figure 11 Digital output connection example The figure represents connections for one channel The other seven channels are connected in the same manner The maximum sink current is 150 mA per 8 channel bank or if all eight channels are used 18 mA maximum per channel Internal pull up pull down capability Unconnected inputs are pulled low by default to 0 V through 47 kQ resistors via jumper J6 on the circuit board The pull up pull down voltage is common to all 47 kQ resistors Complete the following steps to configure these inputs to pull high 5V Caution The discharge of static electricity can damage some electronic components Before removing the USB 2408 Series device from its housing ground yourself using a wrist strap or touch the computer chassis or other grounded object to eliminate any stored static charge To open the case and set the J6 jumper do the following 1 Turn the device over and rest the top of the housing on a flat stable surface 2 Peel off the four rubber feet on the bottom of the device to access the screws 3 Remove the four screws from the bottom of the device 4 Hold both the top and bottom sections together turn the device over and rest it on the surface then carefully remove the top section of the case to expose the circuit board USB 2408 Series User s Guide Functional Details 5 Configure jumper J6 for either pull up pins 1 2 or pull down pins 2 3 T
25. ferential inputs to screw terminals CHOH CHOL to CH7H CH7L DIFF mode requires two wires plus a ground reference Connect one wire to the high positive signal CHxH Connect one wire to the low negative signal CHxL Connect one wire to the analog ground reference AGND Refer to Figure 5 on page 13 for the location of the DIFF inputs When connecting DIFF voltage inputs to a floating voltage source make sure there is a DC return path from each voltage input to ground You make this path by connecting a resistor from each low channel input to an AGND pin A value of approximately 100 kQ can be used for most applications This does not apply to channels configured for TC input as they have their own internal reference Leave unused input channels either floating or tied to an AGND terminal Source impedances should be kept as small as possible to avoid settling time and accuracy errors 14 USB 2408 Series User s Guide Functional Details Figure 7 shows a DIFF voltage connection using a ground path resistor cx CHOH CHOL AGND CH1H CH1L AGND 100 kQ DODOOOO Figure 7 DIFF voltage connection with ground path resistor example Gain queue Use the USB 2408 Series channel gain queue feature to configure a list of channels modes and gains for each scan The settings are stored in a channel gain queue list that is written to local memory on the device The channel gain queue list contains one or mo
26. ge based firmware to interface with the device Refer to the Quick Start Guide for information about the Universal Library and InstaCal Refer to the DAOFlex Software User s Guide for information about DAQFlex software Refer to the Message based Firmware Specification for information about the message based firmware Chapter 3 Functional Details External components USB 2408 Series devices have the following external components USB connector LEDs Screw terminals Figure 2 shows the location of each component Screw terminal pins 23 to 44 Screw terminal 1 Status LED pins 1 to 22 Activity LED USB connector Figure 2 USB 2408 Series components USB connector The USB connector provides 5 V power and communication No external power supply is required LEDs USB 2408 Series devices have two LEDs STATUS and ACTIVITY The Status LED is lit when the device is detected and installed on the computer The Activity LED indicates the communication status of a device This LED blinks when data is transferred and is off when the device is not communicating Figure 3 shows the location of each LED Status LED Activity LED Figure 3 USB 2408 Series LEDs 11 USB 2408 Series User s Guide Functional Details Screw terminals USB 2408 Series devices have two banks of screw terminals Screw terminal functions for DIFF and SE modes are identified in Figure 5 and Figure 4
27. he Mac OS X operating system the Status LED does not turn on until the device is configured by application software Caution Do not disconnect any device from the USB bus while the computer is communicating with the USB 2408 Series device or you may lose data and or your ability to communicate with the device If the Status LED turns off If the Status LED turns on but then turns off the computer has lost communication with the USB 2408 Series device To restore communication disconnect the USB cable from the computer and then reconnect it This should restore communication and the Status LED should turn on USB 2408 Series User s Guide Installing a USB 2408 Series Device Calibrating Self calibration USB 2408 Series hardware supports self calibration You should calibrate the device whenever the ambient temperature changes by more than 10 C from the last self calibration Use either InstaCal or the DAQFlex FlexTest utility to calibrate the device Factory calibration The Measurement Computing Manufacturing Test department performs the initial factory calibration Contact Measurement Computing for details about how to return your device and have it calibrated to the factory specifications Programming and developing applications You can program and develop applications for the USB 2408 Series device using MCC DAQ software and DAQFlex software OEM users can create a custom driver for use with the messa
28. he jumper is configured by default for pull up Figure 12 shows the location of the jumper on the board 1545080 I 1 HUNGARY cit Le m jm ci Ung tttte uL tnttire a uum SAU SAMI gt C ii 151490A 02L HKS DOODS Figure 12 Location of J6 jumper Figure 13 shows the jumper configured for pull up and pull down 1 1 a 3 Pull u Pull dawn default Figure 13 J6 jumper configurations 6 Replace the top section of the case and fasten it to the bottom section with the four screws Replace the rubber feet For more information about digital signal connections For general information about digital signal connections and digital I O techniques refer to the Guide to Signal Connections available on our web site at www mccdaq com signals signals pdf The pull up pull down voltage is common to all of the internal 47 kQ resistors External pull up pull down capability You can also place an external pull up resistor on any of the DIO bits which enables you to pull the DIO bit up to a voltage that exceeds the internal 5 V pull up voltage When using external pull up resistors be aware of the following You should either remove the J6 jumper or store it by attaching it to one of the three pins When using external pull up resistors be aware that the internal resistors cause a slight voltage impedance shift to digital lines in the on state as various lines change between the on off states
29. hether the DOUT is active or tri stated Input voltage range Oto l5 V Input type CMOS Schmitt trigger Input characteristics 47 KQ pull up pull down resistor 28 KQ series resistor Maximum input voltage range 0 V to 20 V max power on off relative to DGND Note 2 Pull up pull down configuration All pins pulled up to 5 V via individual 47 kQ resistors the J6 shorting block default position is pins 1 and 2 Pull down capability is available by placing the J6 shorting block across pins 2 and 3 Transfer rate software paced 500 port reads or single bit reads per second typ Input high voltage 1 3 V min 2 2 V max Input low voltage 1 5 V max 0 6 V min Schmitt trigger hysteresis 0 4 V min 1 2 V max Note 2 DGND pins are recommended for use with digital input and digital output pins The DGND and AGND pins are common and are isolated from earth ground Table 19 Digital output specifications Parameter Specifications Number of I O 8 channels Configuration Note3 Each DIO bit can be independently read from DIN or written to DOUT The DIN bits may be read at any time whether the DOUT is active or tri stated Output characteristics Note 4 47 kQ pull up open drain DMOS transistor Pull up configuration All pins pulled up to 5 V via individual 47 kQ resistors the J6 shorting block default position is pins 1 and 2 Tran
30. ils i 8 AGND Analog ground pr i E ded 8 amp CH7L Al channel 7 low Analog ground AGND 3 8 8 CH7H Al channel 7 high Al channel 1 high CH1H 4 9 AGND Analog ground Al channel flow CH1L 5 CH6L Al channel 6 low Analog ground AGND 6 IS 8 CH6H Al channel 6 high i 8 amp AGND Analog ground X d A eh rab amp CHSL Al channel 5 low Analog ground AGND 9 19 8 CH5H Al channel 5 high Al channel 3 high CH3H 10 18 AGND Analog ground Alchannel 3low CH3L 11 f S CH4L Al channel 4 low Analogground AGND 12 f S CH4H Al channel 4 high AGND Analog ground AOUT1 AO channel 1 AGND Analog ground Digital ground DGND 13 AOUTO AO channel 0 DIO channel 0 DIOO 14 18 DIO channel 1 DIO 15 nnel l BO bre OS i S amp CHAS Chassis ground DIOchannel4 DIO4 18 5V 5 V user output DIO channel 5 DIOS 19 DGND Digital ground DIOchannel6 DIO6 20 S E CTR1 Counter channel 1 DIO channel 7 DIO7 21 18 DGND Digital ground Digital ground DGND 22 1 amp CTRO Counter channel 0 Figure 5 DIFF mode pin out These pins are labeled NC no connection on the USB 2408 Signal connections Input isolation USB 2408 Series devices are isolated data acquisition devices The analog I O digital I O counters and all the digital control timing are referenced to an isolated ground as shown in the figure below This ground is physically and electrically separate from the ground used by the circuit conne
31. le 7 Peak to peak noise performance specifications uV AID data rate Range 3750S s 2000S s 1000S s 500S s 100S s 60S s 50S s 25S s 10S s 5S s 2 5S s 10 V 126 84 100 14 71 76 45 06 30 52 30 52 26 70 19 07 11 92 9 54 9 54 5 V 56 74 47 56 34 21 25 87 16 21 14 31 14 31 14 30 5 96 4 77 4 77 22 5 V 32 96 28 79 17 94 14 19 7 51 7 09 7 09 5 72 3 81 4 00 4 00 1 25 V 18 57 17 52 13 83 9 30 5 48 5 48 5 01 3 81 3 34 3 34 2 86 0 625 V 18 88 16 58 8 45 7 41 5 32 4 80 4 38 3 86 2 50 2 61 1 98 0 3125 V 15 33 14 76 8 19 6 94 4 75 4 69 4 49 3 70 3 34 2 56 2 45 0 15625 V 13 28 16 84 7 47 6 61 5 70 4 48 4 48 4 24 2 66 3 07 2 29 0 078125 V 13 47 15 02 9 17 6 88 4 28 4 16 4 00 3 57 2 28 2 13 2 40 Table 8 RMS noise performance specifications uVRMS AID data rate Range 3750 S s 2000 S s 1000 S s 500 S s 100 S s 60 S s 50 S s 25S s 10S s 5S s 2 5 S s 10 V 19 22 15 17 10 87 6 83 4 62 4 62 4 05 2 89 1 81 1 44 1 44 5 V 8 60 7 21 5 18 3 92 2 46 2 17 2 17 2 16 0 90 0 72 0 72 i2 5V 4 99 4 36 2 72 2 15 1 14 1 07 1 07 0 87 0 58 0 60 0 60 1 25 V 2 81 2 66 2 10 1 41 0 83 0 83 0 76 0 58 0 51 0 51 0 43 0 625 V 2 86 2 51 1 28 1 12 0 81 0 73 0 66 0 58 0 38 0 40 0 30 0 3125 V 2 32 2 24 1 24 1 05 0 72 0 71 0 68 0 56 0 51 0 39 0 37 0 15625 V 2 01 2 55 1 13 1 00 0 86 0 68 0 68 0 64 0 40 0 47 0 35 30 078125 V 2 04
32. ne high performance 16 bit RISC microcontroller for measurements isolated 30 USB 2408 Series User s Guide Specifications Power Table 23 Power specifications Parameter Conditions Specification Supply current Note 8 Quiescent current 275 mA Voltage supervisor limits 4 5 V gt Veg Ot Vet gt 5 5 V PWR LED Off power fault 4 5 V lt Vext lt 5 5 V PWR LED On 5 V user output voltage range Available at terminal block pin 40 4 75 V min to 5 25 V max 5 V user output current Available at terminal block pin 40 10 mA max Isolation Measurement system to PC 500 VDC min Note 8 This is the total quiescent current requirement for the USB 2408 Series which includes up to 10 mA for the status LED This does not include any potential loading of the digital I O bits 5 V user terminal or the AOUTx outputs USB specifications Table 24 USB specifications Parameter Specifications USB device type USB 2 0 full speed Device compatibility USB 1 1 USB 2 0 USB cable type A B cable UL type AWM 2527 or equivalent min 24 AWG VBUS GND min 28 AWG D D USB cable length 3 meters max Environmental Table 25 Environmental specifications Parameter Specifications Operating temperature range 0 C to 50 C max Storage temperature range 40 C to 85 C max Humidity 0 to 9
33. on Pin name CTRO CTRI Number of channels 2 channels Resolution 32 bits Counter type Event counter Input type Schmitt trigger rising edge triggered Input source CTRO pin 44 CTRI pin 42 Counter read writes rates software paced Counter read System dependent 500 reads per second Counter write System dependent 500 writes per second Input characteristics Each CTRx input pin 562 kQ pull up resistor to 5 V 10 kQ series resistor Input voltage range 15 V max Max input voltage range CTRO CTRI relative to AGND and DGND Note 7 20 V max power on off Input high voltage 1 3 V min 2 2 V max Input low voltage 1 5 V max 0 6 V min Schmitt trigger hysteresis 0 4 V min 1 2 V max Input bandwidth 3 dB 1 MHz Input capacitance 25 pf Input leakage current 120 nA 5 V 1 6 mA 15 V Input frequency 1 MHz max High pulse width 500 ns min Low pulse width 500 ns min Note 7 DGND pins are recommended for use with counter input pins The DGND and AGND are common and are isolated from earth ground Memory Table 21 Memory specifications EEPROM 4096 bytes isolated micro reserved for sensor configuration 256 bytes USB micro for external application use Microcontroller Table 22 Microcontroller specifications Type One high performance 8 bit RISC microcontroller with USB interface non isolated O
34. orms averaging and the number of averages equals 30 000 data rate In this example channel 0 is sampled 3000 times over 100 ms and all samples are averaged into one sample Then channel is sampled 600 times over 20 ms and samples are likewise averaged into one sample The final samples are available to you at a maximum rate of about 8 Hz 8 245 Hz Resolution 19 6 bits 640 ps delay before next sample taken Channel 1 H Figure 10 USB 2408 Series data rate vs resolution example Analog output USB 2408 2AO only The USB 2408 2A0 has two 16 bit analog outputs AOUTO and AOUT1 Both outputs can be updated simultaneously at a rate of 500 S s per channel One output can be updated at a rate of 1000 S s The output range is fixed at 10 V The outputs default to 0 V when the host computer is shut down or suspended or when a reset command is issued to the device USB 2408 Series User s Guide Functional Details Digital I O You can connect up to eight digital I O lines to DIOO through DIO7 The digital I O terminals can detect the state of any TTL level input Digital input voltage ranges of up to 0 to 15 V are permitted with thresholds of 0 6 V low and 2 2 V high Each DIO channel is an open drain which when used as an output is capable of sinking up to 150 mA for direct drive applications Figure 11 shows an example of a typical DIO connection Typical DIO channel Isolated microcontroll
35. put 39 CHAS Chassis ground 18 DIO4 Digital input output 40 5V 5 V output 19 DIO5 Digital input output 41 DGND Digital ground 20 DIO6 Digital input output 42 CTR1 Counter 1 21 DIO7 Digital input output 43 DGND Digital ground 22 DGND Digital ground 44 CTRO Counter 0 Note 9 On the USB 2408 these pins are labeled NC no connection 32 USB 2408 Series User s Guide Specifications Table 29 16 channel single ended mode pinout Pin Signal name Pin description Pin Signal name Pin description 1 CHO Channel 0 23 AGND Analog ground 2 CH8 Channel 8 24 CH15 Channel 15 3 AGND Analog ground 25 CH7 Channel 7 4 CH1 Channel 1 26 AGND Analog ground 5 CH9 Channel 9 27 CH14 Channel 14 6 AGND Analog ground 28 CH6 Channel 6 7 CH2 Channel 2 29 AGND Analog ground 8 CH10 Channel 10 30 CH13 Channel 13 9 AGND Analog ground 31 CH5 Channel 5 10 CH3 Channel 3 32 AGND Analog ground 11 CH11 Channel 11 33 CH12 Channel 12 12 AGND Analog ground 34 CH4 Channel 4 13 DGND Digital ground 35 AGND Analog ground 14 DIOO Digital input output 36 AOUT1 Note 10 Analog output 1 15 DIO1 Digital input output 37 AGND Analog ground 16 DIO2 Digital input output 38 AOUTO Note 10 Analog output 0 17 DIO3 Digital input output 39 CHAS Chassis ground 18 DIO4 Digital input output 40 5V 5 V output 19 DIO5 Digital input output 41 DGND Digital ground 20 DIO6 Digital input output 42 CTR1
36. r Signal connections vie soe ssd nee RIDE Ie TRIER eT eee eH E ERR ERREUR dee ces Input isolation eret rette ert tie e rt e born eR Analog TC put iere verveners deon eene dn ssa vee de selon ho ae eh e RII do eei oue sacs eondestnceade ia wee deden Pet jo adea dora one dewaele Analog input mode nnen Gn En TC mput mode 2 nri Analog output USB 2408 2A0 only Digital UO os inet tie e HH Internal pull up pull down capability External pull up pull down capability Counter input annae envennerneeneenneenvennn Ground nnn EP Mech nical dtawi s asen erneer abe Ruhe qme leenen ene 21 Chapter 4 Specifications ished cada ciiintn shad TOT 22 Analog mputiz av sate ore iet ath ek te tp hen fermes sheen ates heeele 22 Channel configurations TR TRIER UNTERE verderen T ERREUR REESE O eden 23 Compatible sensors rss severe ervoor 23 USB 2408 Series User s Guide COUT ACY a erede dacs oa Sule Suck EP gwen aaa ia wo ecu AREE RERO cocoa EE ERES RRA ea bn de a hoe MUERE AENA Thermocouple measurement accuracy Analog input DC voltage measurement accuracy Input bandwidth sn ar eros e RD ERO ee iet ave a ae eee ees Noise performance Channel switching error Thro ghput tate 2o uec aen aal eet te t etia t uet eet tus Analog voltage output USB 2408 2A0 only Analog input output calibration Digital input output COMTET ere are RR OBI RET RON ten e eee
37. re channel numbers and range settings You can configure up to 64 elements The channels can be listed in any order and can include duplicate channels for sampling at different ranges An example of a 12 element list is shown in the table below Sample channel gain queue list Element Channel Range 0 CHO BIP1OV 1 CHI BIP5V 2 CHO BIP2PtSVOLTS 3 CH4 BIP2PtSVOLTS 4 CH8 BIP2PtSVOLTS 5 CHO BIPSV 6 CHI BIPIPt25VOLTS 7 CH7 BIPSV 8 CHO BIPIPt25VOLTS 9 CH15 BIP10V 10 CH9 BIPIPt25VOLTS 11 CH10 BIP2PtSVOLTS Carefully match the gain to the expected voltage range on the associated channel or an over range condition may occur Although this condition does not damage the device it does produce a useless full scale reading and can introduce a long recovery time due to saturation of the input channel For more information about analog signal connections For more information about analog input connections refer to the Guide to Signal Connections this document is available on our web site at www mccdaq com signals signals pdf TC input mode You can make up to eight high resolution DIFF TC measurements with a USB 2408 Series device Built in cold junction compensation sensors are provided for each of the screw terminal blocks and any supported TC type can be attached to any of the 8 TC channels Do not connect TCs as SE doing so can cause false readings 15 USB
38. s device itself 2 5 Sis N A N N Noise free bits o 9 30 000 Sis A a 100 1000 10 000 100 000 10 Data throughput S s Figure 9 USB 2408 Series A D converter data rate vs noise graph If low noise is your main concern you can operate the USB 2408 Series device at very low data rates starting from 2 5 samples per second S s At low rates much of the noise is averaged out of the data and issues such as reference noise become less important At higher data rates higher frequency noise sources are not averaged out and begin to be troublesome These noise sources include the noise inherent in the A D converter itself which is not reducible Since TCs can pick up noise in your environment select a data rate based on the primary noise frequency For example to reduce the effect of 60 Hz noise select a data rate of 60 or a supported submultiple of 60 such as 10 or 5 Multiple channel throughput rates When setting different sample rates for channels be aware that all the channels will be sampled within the same sample window based on the channel with the lowest sample rate For example if you set a 10 Hz data rate for channel 0 and a 50 Hz data rate for channel 1 basically both channels pass the same number of samples per second to the host computer However more averaging is performed on channel 0 samples therefore channel 0 is sampled at a higher resolution The USB 2408 Series A D converter perf
39. sfer rate software paced Digital output 500 port writes or single bit writes per second typ Output voltage range 0 V to 5 V no external pull up resistor internal 47 KQ pull up resistors connected to 5 V by default 0 V to 15 V max Note 5 Note 6 Drain to source breakdown 50 V min voltage Off state leakage current 1 0 pA Sink current capability 150 mA max continuous per output pin 150 mA max continuous for all eight channels DMOS transistor on resistance drain to source 4Q Note 3 DGND pins are recommended for use with digital input and digital output pins The DGND and AGND pins are common and are isolated from earth ground Note 4 Note 5 Each DMOS transistor source pin is internally connected to DGND The external pull up is connected to the digital output bit through an external pull up resistor Adding an external pull up resistor connects it in parallel with the internal 47 kQ pull up resistor of that particular digital input output bit Careful consideration should be made when considering the external pull up resistor value and the resultant pull up voltage produced at the load Note 6 pull up resistor Does not include the additional leakage current contribution that may occur when using an external 29 USB 2408 Series User s Guide Specifications Counter Table 20 CTR specifications Parameter Conditions Specificati
40. structions for reaching Tech Support Fax 508 946 9500 to the attention of Tech Support Email techsupport mccdaq com Chapter 1 Introducing the USB 2408 Series Overview USB 2408 Series features The USB 2408 Series includes the following devices USB 2408 USB 2408 2A0 These devices are USB 2 0 full speed devices that are supported under the following operating systems Microsoft Windows 7 Vista XP 32 bit or 64 bit Microsoft Windows CE Macintosh 32 bit or 64 bit Linux 32 bit or 64 bit Each USB 2408 Series device provides the following features 16 single ended SE or eight differential DIFF 24 bit analog inputs with sampling rates up to 1 kS s Each channel is software configurable as SE or DIFF For each DIFF channel pair you lose one SE channel Analog input ranges of 10 V 5 V 2 5 V 1 25 V 0 625 V 0 312 V 0 156 V and 0 078 V Up to eight analog inputs can be configured as DIFF thermocouple TC inputs which include built in cold junction compensation and open TC detection Computer protection provided through a minimum of 500 VDC input isolation between field wiring and the USB interface Eight lines of digital I O and two 32 bit counters Screw terminals for field wiring connections The USB 2408 2A0 also provides two 16 bit analog output channels You can pace a single channel at rates of up to 1 kS s You can pace both channels simultaneously at rates of up
41. ting trademarks Other product and company names mentioned herein are trademarks or trade names of their respective companies 2011 Measurement Computing Corporation All rights reserved No part of this publication may be reproduced stored in a retrieval system or transmitted in any form by any means electronic mechanical by photocopying recording or otherwise without the prior written permission of Measurement Computing Corporation Notice Measurement Computing Corporation does not authorize any Measurement Computing Corporation product for use in life support systems and or devices without prior written consent from Measurement Computing Corporation Life support devices systems are devices or systems that a are intended for surgical implantation into the body or b support or sustain life and whose failure to perform can be reasonably expected to result in injury Measurement Computing Corporation products are not designed with the components required and are not subject to the testing required to ensure a level of reliability suitable for the treatment and diagnosis of people HM USB 2408 Series doc 2 Table of Contents About this User s Guide rn ree eee eed a eue slaved nnde aaaea Eaa 5 What you will learn from this user s guide naan enne enne ennvenseenseeneensevenensnenseenneenneenneeneenneen nnne 5 Conventions in this user s guide nanne annen en sersnenseenseerneennvenseeneennenenneenseensennvennensn
42. to 500 S s USB 2408 Series User s Guide Introducing the USB 2408 Series USB 2408 Series block diagram USB 2408 Series functions are illustrated in the block diagram shown here Calibration Voltage Sources Microcontroller and FPGA Bitwise Programmable DIO Isolation Microcontroller with full speed USB 2 0 Isolated Power Supplies 12V 12V Non lsolated 33V 5V Power Supply Figure 1 USB 2408 Series functional block diagram Chapter 2 Installing a USB 2408 Series Device What comes with your shipment As you unpack your USB 2408 Series device verify that the following components are included Hardware USB 2408 Series device USB 2408 or USB 2408 2A0 USB cable 2 meter length Documentation In addition to this hardware user s guide a Quick Start Guide booklet is included with the USB 2408 Series shipment This booklet provides an overview of the MCC DAQ software you received with the device and includes information about installing the software Please read this booklet completely before installing any software or hardware Unpacking As with any electronic device take care while handling to avoid damage from static electricity Before removing the USB 2408 Series device from its packaging ground yourself using a wrist strap or by simply touching the computer chassis or other grounded object to eliminate any stored static charge If the device is damaged notify
43. ture reading The TC linearization uses the latest NIST linearization coefficients for each of the eight TC types supported by USB 2408 Series devices When configuring TC sensors keep any stray capacitance as small as possible relative to AGND to avoid settling time and accuracy errors For TC channels do not provide a return path to ground This is done internally Figure 8 shows a typical TC connection 24 bit ADS1256 Figure 8 DIFF TC connection example Noise filtering data rate and throughput rate Although the USB 2408 Series A D converter has a maximum data rate of 3 750 samples per second the actual throughput rate you observe for voltage and temperature data 1s determined by these formulas Maximum single channel throughput 1 1 data rate TEMAS Maximum multiple channel throughput 1 y 1 da Mata rate n 640us where 7 is the number of channels See Table 18 and Table 19 in the Specifications chapter for details 16 USB 2408 Series User s Guide Functional Details This drop off in throughput rate is due to the noise filtering feature in the device You can control the amount of the noise filtering by adjusting the data rate setting By reducing the data rate the averaging of samples increases and noise drops correspondingly Figure 9 illustrates this inverse relationship This graph applies to the A D converter only do not expect this level of performance from a USB 2408 Serie
44. ve warm up the USB 2408 Series device for 45 minutes after the initial power on The accuracies listed above are only guaranteed if the device is housed in the plastic enclosure Analog input DC voltage measurement accuracy Table 5 DC Accuracy components and specifications All values are Offset Gain temperature temperature Gain error Offset INL error Absolute coefficient coefficient Range of reading error of range accuracy reading C HV C 10 V 0 0037 50 uV 0 0008 500 uV 0 0006 3 5 V 0 0047 25 uV 0 0008 300 uV 0 0006 2 2 5 V 0 0059 20 uV 0 0008 200 uV 0 0006 1 1 25 V 0 0056 20 uV 0 0008 100 uV 0 0006 1 0 625 V 0 0068 15 uV 0 0005 60 uV 0 0006 1 0 3125 V 0 0104 15 uV 0 0006 50 uV 0 0006 1 0 15625 V 0 0184 10 uV 0 0005 40 uV 0 0006 1 0 078125 V 0 0384 10 uV 0 0009 40 pV 0 0006 1 24 USB 2408 Series User s Guide Specifications Input bandwidth Table 6 input bandwidth A D data rate 3 db Bandwidth Hz 3750 S s 1615 2000 S s 878 1000 S s 441 500 S s 221 100 S s 44 2 60 S s 26 5 50 S s 22 1 25 S s 11 1 10 S s 4 42 5 S s 2 21 2 5 S s 1 1 Noise performance For the peak to peak noise distribution test a differential input channel is connected to AGND at the input terminal block and 50 000 samples are acquired at the maximum rate available at each setting Tab
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