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DT7837 User's Manual

1. Connector Connector Pin Number Signal Description Pin Number Signal Description 59 In Serial Data 4 50 In Serial Data 5 61 In Serial Data 6 62 In Serial Data 7 63 Ground 64 Ground 65 In Parallel Data 0 66 In Parallel Data 1 67 In Parallel Data 2 68 In Parallel Data 3 69 In Parallel Data 4 70 In Parallel Data 5 71 In Parallel Data 6 72 In Parallel Data 7 73 Ground 74 Ground 75 Control 0 76 Control 1 77 Control 2 78 Control 3 79 Control 4 80 Control 5 81 Control 6 82 Control 7 83 Ground 84 Ground 85 Control 8 86 Control 9 87 Control 10 88 Control 11 89 Control 12 90 Control 13 91 Control 14 92 Control 15 93 Ground 94 Ground 95 Out Parallel Data O 96 Out Parallel Data 1 97 Out Parallel Data 2 98 Out Parallel Data 3 99 Out Parallel Data 4 100 Out Parallel Data 5 101 Out Parallel Data 6 102 Out Parallel Data 7 103 Ground 104 Ground 105 Out Serial Data O 106 Out Serial Data 1 107 Out Serial Data 2 108 Out Serial Data 3 109 Out Serial Data 4 110 Out Serial Data 5 111 Out Serial Data 6 112 Out Serial Data 7 113 Ground 114 Ground 115 Out Sync Control O 116 Out Sync Control 1 117 Out Sync Control 2 118 Out Sync Control 3 119 Ground 120 Ground 9 Connector Pin Assignments and LED Status Indicators STP26 Screw Terminal Panel The STP26 contains one 26 pin connector and a screw terminal block TB1 The 26 pin connector provides access to the
2. Feature Specifications Output voltage 5 VDC to Output current 2 A with 4 A surge capability Noise and ripple 50 mVpp 74 Connector Pin Assignments and LED Status Indicators Analog Tut COMAS ocio ee ou ce ete ree piane pei 76 bella 77 USB Device Client Connector 222 cssc gee i 79 USE ESE OMe od illa ae 80 Eternel Connector i ts is ESALTA DRED ERS BEES EEE REE SERRE ES 81 Micro SD Cand Connector a ia HE d I nee tee ae 82 External 45 V Power COME coi ii ea ae 83 anii si sci EE 85 LO Block Connector iustos tek DRE e ce Oe ede E eR Uaec es 88 STE25 Screw Terminal Panel 2 daten erbe Eh eR a 91 LED Status Indicatori is ia RR CREDE OR DECR E DERART RA 93 75 Appendix B Analog Input Connectors Figure 13 shows the layout of the analog input SMA connectors connectors J1 J5 on the I O block top board of the DT7837 module Channel n Analog In Channel n Analog In Return Figure 13 Analog Input Connectors 76 Connector Pin Assignments and LED Status Indicators Digital Connector Figure 14 shows the layout of the 26 pin Digital connector J8 on the ARM block bottom board of the DT7837 module This connector brings out the tachometer GPIO and event output signals for the module 25 1 PR XL III 26 2 UODODOUOGOO UU 100 Figure 14 Layout of the Digital Connector Table 17 lists the pin assignments for the Digital connector on the DT7837 module Table 17 Pin Assig
3. LL eh 39 Event Counting eere RDDRR RS He S aequ tenes equ SL A IRURE es 39 Rate Generation oc SLE EM br b dete etes 40 Non Repeatable One Shot eee 41 Idle Mode iii dera Ra a dial kb ANE Rea RN 42 Measure Counter Features L eee ee ht ha hr teen 43 Digital I O Features 4 esee eene aee ette aac ee s et a rer see cae eeu 47 Digital 1 O Lanes ener refe eI es ed ipu ed ER UE Hr Rede 47 Op ratiori Modes 2 2 m Ed n ESO Ur E ERR Tae ada tas 47 Triggering Acquisition on Multiple Modules nunnan ernan 48 Chapter 3 Troubleshooting Li 49 Technical Support 2 22 Re mque mede e o E ea Au 50 If Your Module Needs Factory Service LL 51 Chapter 4 Calibration ecaa a i perire i ie a a 53 OVerviQW ssa A A I ona Por ree et 54 Using the Calibration Utility soes ssag estont LL 55 Calibrating the Analog Input Subsystem 56 Warming up the Module rr 56 Connecting a Precision Voltage Source 0 56 Using the Auto Calibration Procedure ca 56 Using the Manual Calibration Procedure eee ee 57 Restoring Factory Calibration Settings ra 58 Appendix A Specifications iii 59 Analog Input Specifications isses n 60 Digital Input Specifications LL 63 Digital Output Specifications isses ene 64 Tachometer Input Specifications 65 Measure
4. You specify one of the general purpose input pins 1 to 8 of the Digital connector on the DT7837 module as the external C T gate input Ensure that you physically connect the external gate signal to the selected pin Refer to page 27 for the pin descriptions of the Digital connector 37 Chapter 2 38 High external gate input Specifies a logic high or rising edge gate type For event counting and rate generation mode the operation is enabled when the counter s gate signal is high and is disabled when the counter s gate signal is low For one shot mode or repetitive one shot mode the operation is enabled when the counter s gate signal goes from a low to a high transition and is disabled when the counter s gate signal goes from a high to a low transition You specify one of the general purpose input pins 1 to 8 of the Digital connector on the DT7837 module as the external C T gate input Ensure that you physically connect the external gate signal to the selected pin Refer to page 27 for the pin descriptions of the Digital connector Pulse Output Period Pulse Width and Polarity If you want to perform a C T output operation define one of the general purpose output pins 11 to 18 of the Digital connector on the DT7837 module as the external C T output signal using software Then connect the external C T output signal to the selected pin Refer to page 27 for the pin descriptions of the Digital connector For the DT7
5. 10 mA maximum Logic low output current 4 mA maximum Short circuit current 50 mA maximum Clocked with sample clock Currently not supported 64 Specifications Tachometer Input Specifications Table 7 lists the specifications for the tachometer input available on the Digital connector of the DT7837 module Table 7 Tachometer Input Specifications Feature Specifications Number of channels 1 Resolution 31 bits per channel Input voltage range 30 V Threshold voltage 2 V with 0 5 V hysteresis Input termination None Maximum input frequency 1 MHz Minimum pulse width high low minimum amount of 0 4 us time it takes a C T to recognize an input pulse Clock frequency for tachometer measurements 12 MHz 83 ns resolution Overvoltage protection 30 V Clocked with sample clock Yes if the tachometer is included in the input data stream channel bit 4 a Limited by signal integrity and input signal conditioning 65 Appendix A 66 Measure Counter Specifications Table 8 lists the specifications for the measure counter on the DT7837 module Table 8 Measure Counter Specifications Feature Specifications Number of measure counters 4 Resolution 31 bits per channel Clock frequency for measurement counters 48 MHz 20 8 ns resolution Maximum input frequency 10 MHz Minimum pulse width high low 50 ns 0 4 us if the tachome
6. Master Oscillator Specifications Table 11 lists the specifications for the master oscillator on the DT7837 module Table 11 Master Oscillator Specifications Feature Specifications Frequency 48 MHz Frequency stability 30 ppm a Stability budget consists of initial tolerance operating temperature range rated power supply voltage change load change 10 year aging shock and vibration 69 Appendix A 70 Power Physical and Environmental Specifications Table 12 lists the power physical and environmental specifications for the DT7837 module Table 12 Power Physical and Environmental Specifications Feature DT7837 Specifications Power 5 VDC 2 A maximum Warm up time 1 hour Physical Dimensions Depth Width Height Weight 6 28 in 159 5 mm 3 937 in 100 mm 1 30 in 33 mm 7 2 oz 204 g Environmental Operating temperature range Storage temperature range Relative humidity Altitude 0 C to 55 C 25 C to 85 C To 95 noncondensing To 10 000 feet Specifications Regulatory Specifications The DT7837 module is CE compliant Table 13 lists the regulatory specifications for the DT7837 module Table 13 Regulatory Specifications Feature DT7837 Specifications Emissions EMI FCC Part 15 Class A EN55011 2007 Based on CISPR 11 2003 A2 2006 Immunity EN61326 1 2006 Electrical Equipment
7. J2 on the ARM block bottom board of the DT7837 module This is a type A connector Figure 16 Layout of the USB Type A Connector for the USB Host Port Table 19 lists the pin assignments for the USB type A connector on the DT7837 module for the USB host port Table 19 Pin Assignments for the USB Type B Connector for the USB Device Client Port Connector Connector Pin Number Signal Description Pin Number Signal Description 1 USB 5 V 3 USB Data 2 USB Data 4 USB Ground Note The outer shell provides cable shield to chassis ground 80 Connector Pin Assignments and LED Status Indicators Ethernet Connector Figure 15 shows the layout of the Ethernet RJ45 connector J1 on the ARM block bottom board of the DT7837 module Figure 17 Layout of the Ethernet Connector Table 20 lists the pin assignments for the Ethernet connector on the DT7837 module Table 20 Pin Assignments for the Ethernet Connector Connector Connector Pin Number Signal Description Pin Number Signal Description 1 Transmit 5 Not connected 2 Transmit 6 Receive 3 Receive 7 Not connected 4 Not connected 8 Not connected LED1 Activity green LED2 Link yellow Note The outer shell provides cable shield to chassis ground 81 Appendix B Micro SD Card Connector Figure 18 shows the layout of the Micro SD Card connector J5 on the ARM blo
8. Card A micro SD card slot is provided to support optional high speed up to 24 MB s micro SD cards Micro SD cards not provided with the module communicate with the AM3352 processor using the MMCO port in the 4 bit interface mode You can use a micro SD card as a boot source or for general purpose file and data storage USB Device Client Port The DT7837 module provides a USB 2 0 device client port on a type B receptacle The device port connects to the USB port 0 controller of the AM3352 processor When connected to a host computer through this USB port the host computer can identify the DT7837 module and load the appropriate drivers through the enumeration process USB Host Port The DT7837 provides a high speed USB 2 0 host port on a type A receptacle The host port connects to the USB port 1 controller of the AM3352 processor The USB host port supports any USB device provided that the required software is installed on the Linux operating system If desired you can connect USB devices such as a keyboard mouse memory stick or hub to this port Serial Port 0 Serial port 0 is a 3 3 V TTL serial interface provided on a 6 pin header This port supports transmit and receive signals no handshaking and connects to the UART 0 interface of the AM3552 processor This port is particularly useful when you are debugging your applications To use this port use the EP405 USB to serial TTL adapter cable Serial Port 1 12C2
9. Counter timer operations start on the rising edge of the clock input signal Note If you specify a counter timer in the input stream the A D clock determines how often you want to read the counter value Refer to page 32 for more information about the A D sample clock Gate Types The edge or level of the counter gate signal determines when a counter timer operation is enabled Unless you are using a software gate no gate define one of the general purpose input pins of the Digital connector on the DT7837 module as the external C T gate input using software Then physically connect the external gate signal to the selected pin Refer to page 27 for the pin descriptions of the Digital connector DT7837 modules provide the following gate types you select the gate type using software e None A software start command enables any counter timer operation immediately after execution No general purpose input signal is required if a gate type of None is selected e Low external gate input Specifies a logic low or falling edge gate type For event counting and rate generation mode the operation is enabled when the counter s gate signal is low and is disabled when the counter s gate signal is high For one shot mode or repetitive one shot mode the operation is enabled when the counter s gate signal goes from a high to a low transition and is disabled when the counter s gate signal goes from a low to a high transition
10. DC Signal to Noise Ratio SNR is the ratio of the RMS value of the input signal to the RMS sum of all other spectral components excluding harmonics and DC Total Harmonic Distortion THD is the ratio of the RMS value of the input signal to the RMS sum of all harmonics Spurious Free Dynamic Range SFDR is the ratio of the RMS full scale range to the RMS value of the largest peak spurious component including harmonics Specifications Digital Input Specifications Table 5 lists the specifications for the digital input signals available on the Digital connector of the DT7837 module Table 5 Digital Input Specifications Feature Specifications Number of general purpose inputs 8 Input type 3 3 V high speed CMOS Schmitt trigger 5 V tolerant Input termination 22 1 kQ pull up resistor to 3 3 V Voltage threshold 2 0 V typical Voltage threshold 0 8 V typical Clocked with sample clock Yes if the digital input port is included in the input data stream channel bit 7 63 Appendix A Digital Output Specifications Table 5 lists the specifications for the digital output signals available on the Digital connector of the DT7837 module Table 6 Digital Output Specifications Feature Specifications Number of general purpose outputs 8 Output type LVTTL Logic high output voltage 2 4 V minimum Logic low output voltage 0 4 V maximum Logic high output current
11. Specifications Analog Input Spec COME cs eese deett erm ed nr ne eee e n s Re mad etna 60 Digital Input Sp Scans tsi eels A GI eS ia 63 Digital Output Specifications cirer erede ad 64 Tachometer Input Specifications ccoo ci RR 65 Measure Counter Sped heationS eisir ia aiii lo E 66 General Purpose Counter Timer Specifications 0 0 6 62 cee nee pe a 67 WI SBECHICHEIOUE RR RES eim O NIE 68 Master Oscillator Specicatlons 03 ia 69 Power Physical and Environmental Specifications 9 oo 70 ae c nce sheds RA 71 Conector Se CHICROINS ouo n ee tutte de oe haa ele EE 72 External Power Supply Specilficabons esce sreci erore dreien ERE SER ER cage eae 73 59 Appendix A Analog Input Specifications Table 4 lists the specifications for the analog input subsystem on the DT7837 module Table 4 Analog Input Subsystem Specifications Feature DT7837 Specifications Number of analog input channels 4 single ended Resolution 24 bits Ranges and gains Gain of 1 10V Gain of 10 1V A D type Delta Sigma Data encoding Offset binary Input FIFO 2 kSamples s Maximum sample rate 105 469 kS s Minimum sample rate 195 3125 S s ADC master clock range Sampling frequency lt 52 734 kHz 52 734 kHz to 105 469 kHz 100 kHz to 27 MHz 512 x sample frequency 256 x sample frequency Group delay 39 sample rate in seconds ADC Delta Sigma filt
12. experience problems using the DT7837 module follow these steps 1 Readall the appropriate sections of this manual and the DT7837 File I O Programming Manual 2 Refer to the supplied example programs for clarification 3 Check that you have installed your hardware devices properly 4 Check that you have installed the software properly If you are still having difficulty using the DT7837 module Data Translation s Technical Support Department is available to provide technical assistance To request technical support go to our web site at http www datatranslation com and click on the Support link When requesting technical support be prepared to provide the following information Your product serial number e The hardware software product you need help on If you are located outside the USA contact your local distributor see our web site www datatranslation com for the name and telephone number of your nearest distributor 50 Troubleshooting If Your Module Needs Factory Service If your module must be returned to Data Translation do the following 1 Record the module s serial number and then contact the Customer Service Department at 508 481 3700 ext 1323 if you are in the USA and obtain a Return Material Authorization RMA If you are located outside the USA call your local distributor for authorization and shipping instructions see our web site www datatranslation com for the name and telephone
13. for Measurement Control and Laboratory Use EMC Requirements EN61000 4 2 2009 Electrostatic Discharge ESD 4 kV contact discharge 8 kV air discharge 4 kV horizontal and vertical coupling planes EN61000 4 3 2006 Radiated electromagnetic fields 3 V m 80 to 1000 MHz 3 V m 1 4 GHz to 2 GHz 1 V m 2 GHZ to 2 7 GHZ EN61000 4 4 2004 Electrical Fast Transient Burst EFT 1 kV on data cables EN61000 4 6 2009 Conducted immunity requirements 3 Vrms on data cables 150 kHz to 80 MHz RoHS EU Directive 2002 95 EG Compliant as of July 1st 2006 Safety UL CSA 71 Appendix A 72 Connector Specifications Table 14 lists the connector specifications for the DT7837 module Connector Table 14 Connector Specifications Board Reference Designator Part Number of Connector on Module Part Number of Mating Connector Analog input SMA connectors J1 J5 on I O block Amphenol Connex 132203 Ethernet RJ45 connector J1 on ARM block Bothhand LU1S041C 43 LF USB host connector J2 on ARM block TE Connectivity 292336 1 USB device client connector J4 on ARM block TE Connectivity 292304 2 MicroSD connector J5 on ARM block Molex 503182 1853 External power supply DIN connector 3 Pin header J6 on ARM block TB1 on ARM block Kycon KPJX 4S S Phoenix Contact 1707434 Kycon KPPX 4P Phoenix Contact 1839610 Digital conne
14. is set and the stale measure count is written into the input data stream e If another input subsystem sample occurs before another measure completes and the Stale flag is disabled then the Stale flag is not set and the stale measure count is written into the input data stream If the input sample rate is slower than the tachometer input frequency then as each period measurement completes a new count value is stored When the input subsystem sample occurs the most recently stored measure count is written into the input data stream A data pipeline is used in the hardware to compensate for the A D group delay and synchronizes the value of the tachometer input with the analog input measurements so that all measurements are correlated in time The tachometer input is treated like any other channel in the analog input channel list therefore all the triggering and conversion modes supported for analog input channels are supported for the tachometer input Principles of Operation When you read the value of the tachometer input as part of the analog input data stream you might see results similar to the following Table 1 An Example of Reading the Tachometer Input as Part of the Analog Input Data Stream Tachometer Time AID Value Input Value Status of Operation 10 5002 0 Operation started but is not complete 20 5004 0 Operation not complete 30 5003 0 Operation not complete 40 5002 12373 Operati
15. number of your nearest distributor All return shipments to Data Translation must be marked with the correct RMA number to ensure proper processing 2 Using the original packing materials if available package the module as follows Wrap the module in an electrically conductive plastic material Handle with ground protection A static discharge can destroy components on the module Place in a secure shipping container 3 Return the module to the following address making sure the RMA number is visible on the outside of the box Customer Service Dept Data Translation Inc 100 Locke Drive Marlboro MA 01752 1192 51 Chapter 3 52 Y Calibration EIN ii A A A AA ee atte 54 Meme the Calibration IES o ccoo nora ios ri eke aur gaa e n wes 55 Calibrating the Analog Input Subsystem LL 56 53 Chapter 4 Overview DT7837 modules are calibrated at the factory and should not require calibration for initial use We recommend that you check and if necessary readjust the calibration of the analog circuitry every six months using the DT7837 Calibration Utility The DT7837 Calibration Utility is provided as both a web application cal server and a command line program dt7837cal This chapter describes how to calibrate the analog input subsystem of a DT7837 module using the command line program dt7837cal 54 Calibration Using the Calibration Utility To use the command line DT
16. pins on the Digital connector for the external Clock Input Signal internal or external p Counter gt NENNEN Gate Input Signal software or external input Figure 9 Counter Timer Channel Pulse Output Signal C T clock input external C T gate input and C T clock output signals To read the value of C T 0 in the input stream specify bit 5 in the channel mask of the input stream 36 Principles of Operation C T Clock Input Sources The following clock input sources are available for the general purpose counter timer you select the clock source through software e Internal C T clock The internal C T clock uses a 48 MHz time base This clock source is typically used for one shot repetitive one shot and rate generation operations External C T clock An external C T clock is useful when you want to pace counter timer operations at rates not available with the internal C T clock or if you want to pace at uneven intervals The frequency of the external C T clock can range from 0 0112 Hz to 10 MHz This clock source is typically used for event counting and rate generation operations Using software specify one of the general purpose input pins 1 to 8 of the Digital connector on the DT7837 module as the external C T clock input Then physically connect the external clock signal to the selected pin Refer to page 27 for the pin descriptions of the Digital connector
17. ranges 29 resolution 30 Input Trigger LED 93 internal C T clock 37 internal sample clock 32 K kernel device driver 18 L LED status indicators 93 Input Trigger 93 Output Trigger 93 Power 93 lines digital I O 47 M master oscillator 32 specifications 69 measure counter features 43 specifications 66 memory 25 micro SD card 26 connector 82 N NAND flash 25 non repeatable one shot 41 Nyquist Theorem 32 O oscillator specifications 69 output pulses 40 41 Output Trigger LED 93 P physical specifications 70 polarity of counter output signal 38 ports digital I O 47 power connector 3 pin Phoenix header 84 DIN 83 Power LED 93 power specifications 70 74 processor 25 pulse output non repeatable one shot 41 period 38 pulse width 38 rate generation 40 pulse width 38 Index R ranges analog input 29 rate generation 40 regulatory specifications 71 resolution analog input 30 digital I O 47 returning boards to the factory 51 RMA 51 S sample clock 32 SD card 26 SDRAM 25 serial connectors 85 serial peripheral interface 27 86 serial port 0 26 85 86 87 serial port 1 26 serial port 1 connector 87 signals used on processor 27 size module 70 software trigger 31 specifications 59 analog input 60 connector 72 counter timer 67 counter timer specifications 66 environmental 70 EP361 external power supply 73 external power for the 3 position header 74 master oscillator 69 physical
18. signals from the Digital connector on the DT7837 module Figure 26 shows the layout of the STP26 screw terminal panel Figure 26 Layout of the STP26 Screw Terminal Panel Table 28 lists the screw terminal assignments for the STP26 screw terminal panel 91 Appendix B Table 28 Screw Terminal Assignments for the STP26 Screw Terminal Panel Screw Terminal Signal Description X Shield 26 Digital Ground 25 5 V 24 Digital Ground 23 Tachometer Input 22 Digital Ground 21 Reserved for future use 20 Digital Ground 19 Digital Ground 18 General Purpose Output 7 17 General Purpose Output 6 16 General Purpose Output 5 15 General Purpose Output 4 14 General Purpose Output 3 13 General Purpose Output 2 12 General Purpose Output 1 11 General Purpose Output 0 10 Digital Ground 9 Digital Ground 8 General Purpose Input 7 7 General Purpose Input 6 6 General Purpose Input 5 5 General Purpose Input 4 4 General Purpose Input 3 3 General Purpose Input 2 2 General Purpose Input 1 1 General Purpose Input 0 92 Connector Pin Assignments and LED Status Indicators LED Status Indicators The DT7837 module has a Power LED indicator on the ARM block bottom board and trigger LEDs on the I O block top board as shown in Figure 27 Input Trigger LED Output Trigger LED Power LED Figure 27 Power LED on the DT7837 Module These LEDs are
19. with digital positional data measuring the frequency of a signal or as a tachometer An internal 48 MHz counter is used for the measurement yielding a resolution of 20 ns 1 48 MHz Using software commands you can configure the following parameters for the measure counter e The signals that start and stop the measurement Refer to Table 2 for the supported start and stop signals Table 2 Possible Start and Stop Signals Signal Connection Required A D conversion complete No connection required Tachometer input falling edge or rising edge Connect to Tachometer input Digital input 0 falling edge or rising edge Connect a digital input external A D trigger C T clock input or C T gate input to general purpose input O pin 1 of the Digital connector By default this is digital input 0 Digital input 1 falling edge or rising edge Connect a digital input external A D trigger C T clock input or C T gate input to general purpose input 1 pin 2 of the Digital connector By default this is digital input 1 Digital input 2 falling edge or rising edge Digital input 3 falling edge or rising edge Connect a digital input external A D trigger C T clock input or C T gate input to general purpose input 2 pin 3 of the Digital connector By default this is digital input 2 Connect a digital input external A D trigger C T clock input or C T gate input to general purpose inpu
20. 37 Module Principles of Operation ARM Block The ARM block of the DT7837 module uses the TI Sitara AM3352 processor and its associated peripherals to provide an open source single board computer The AM3352 supports many different interfaces many of which are shared on the configurable I O pins In addition to the AM3352 the DT7837 module uses an embedded NAND flash and an FPGA This section describes the features of the ARM block in more detail ARM Processor The AM3352 is based on the ARM Cortex 8 32 bit processor and is configured to run at 600 MHz Refer to the following web site for more information on this processor http www ti com product am3352 Memory A 512 MB DDR3 SDRAM memory device is connected to the AM3352 processor through a dedicated DDR Double Data Rate memory interface Embedded NAND Flash A 2 GB embedded NAND flash device is connected to the AM3352 processor through the 16 bit GPMC General Purpose Memory Controller bus and can be accessed at the CSO address space The flash memory contains the Linux kernel bootloader and the file system You can also use the flash memory for general purpose data and file storage as well as for input data and waveform storage EEPROM An 8 kByte EEPROM device is connected to the 12C0 2 wire serial interface of the AM3352 processor The EEPROM stores information about the device including the calibration information 25 Chapter 2 26 Micro SD
21. 70 power 70 regulatory 71 tachometer input 65 triggers 68 SPI connector 86 SPI port 27 start trigger external digital TTL trigger 31 software 31 threshold trigger 32 STP25 screw terminal panel 91 STP26 screw terminal panel 19 91 T tachometer input features 34 specifications 65 technical support 50 threshold trigger 32 transferring input data 33 triggers external 31 software 31 specifications 68 threshold 32 troubleshooting 50 TTL trigger 31 type A connector 80 type B USB connector 79 U UART 0 85 86 87 UART 1 87 UARTO 26 UARTI 26 units counter timer 36 USB client port 26 USB device connector 79 USB device port 26 USB host connector 80 USB host port 26 V voltage ranges 29 W warm up time 56 97 Index 98
22. 7837 Calibration Utility perform the following steps 1 From the usr local dt7837 dt7837 calibration directory on the module type dt7837cal and press Enter The main screen of the DT7837 Calibration Utility appears 6 dev ttyUSBO PuTTY 2 Once the calibration utility is running calibrate the analog input circuitry either automatically or manually as described on page 56 55 Chapter 4 56 Calibrating the Analog Input Subsystem This section describes how to use the DT7837 Calibration Utility to calibrate each analog input channel of the DT7837 module Warming up the Module Before calibrating the analog input circuitry ensure that the module has been powered on for at least one hour Connecting a Precision Voltage Source To calibrate the analog input circuitry you need to connect an external precision voltage source to the DT7837 module that is capable of generating 0 0000 V to 9 3750 V Connect the precision voltage source to the first analog input channel that you want to calibrate typically analog input channel 0 Using the Auto Calibration Procedure Auto calibration is the easiest to use and is the recommended calibration method To auto calibrate the analog input subsystem do the following 1 10 From the main menu of the program select 2 Automatically calibrate an analog input channel Enter the number 0 to 3 of the analog input channel that you want to calibrate then enter Y to conti
23. 837 module you can program the polarity of the output pulse active high or active low For an active high pulse the high portion of the total pulse output period is the active portion of the counter timer pulse output signal For an active low pulse the low portion of the total pulse output period is the active portion of the counter timer pulse output signal Using software you can specify the number of input clock cycles that are used to create one period of the counter clock output signal You can also specify the number of input clock cycles used to create the active pulse width or duty cycle of the C T output signal For example if you are using an external C T clock running at 10000 Hz as the input clock source of the counter timer and you want to generate a output signal of 1000 Hz with a 20 duty cycle specify a period of 10 10000 Hz divided by 10 is 1000 Hz and a pulse width of 2 the period of 10 multiplied by 20 This is illustrated in Figure 10 Active Pulse Width 2 for 20 duty cycle high pulse low pulse a e Total Pulse Period 10 With an external C T input clock of 10000 Hz and a period of 10 the output signal is 1000 Hz Figure 10 Example of a Pulse Output Principles of Operation Note If you are using an internal C T clock input source you can output pulses using a maximum frequency of 24 MHz Note however that the integrity of the signal degrades at fr
24. Appendix B Figure 20 shows the layout of the 3 pin Phoenix header TB1 on the ARM block bottom board of the DT7837 module Terminal 1 Figure 20 Layout of the 3 Position Phoenix Header Table 23 lists the terminal assignments for the 3 position header on the DT7837 module Table 23 Terminal Assignments for the 3 Position Header TB1 on the DT7837 Module Terminal 2 Terminal 3 Terminal Number Signal Description 1 5 VDC 2 Digital Ground 3 Chassis Ground Note that you must connect an external power supply to this header that meets the specifications described on page 74 84 Connector Pin Assignments and LED Status Indicators Serial Connectors Figure 15 shows the layout of the 6 pin serial connectors J12 J13 and J14 on the ARM block bottom board of the DT7837 module Serial Port 0 Serial SPI Port 1 Port 1202 Port Figure 21 Layout of the Serial Connectors These connectors are described in the sections that follow Serial Port 0 UART 0 Figure 15 shows the layout of the Serial port 0 J13 on the ARM block bottom board of the DT7837 module 6 1 QUELLE TL S Note that the pin order of connector J13 is reversed from connectors J12 and J14 Figure 22 Layout of Serial Port 0 J13 85 Appendix B Table 24 lists the pin assignments for serial port 0 on the DT7837 module Table 24 Pin Assignments for Serial Port 0 J13
25. Counter Specifications een 66 General Purpose Counter Timer Specifications ra rran rrr rnrn 67 Trigger 5pecificadoris ui ds ead Sa o ea e e EM 68 Master Oscillator Specifications 69 Power Physical and Environmental Specifications 70 Contents Regulatory Specifications LL 71 Connector Specifications iii rai rra iii pa Ue 72 External Power Supply Specifications 73 Appendix B Connector Pin Assignments and LED Status Indicators 75 Analog Input Connectors 76 Digital Connector icem p ioe ed de hb p Y du ie rea ERGO ema des 77 USB Device Client Connector eesseeeeeeeeeee eee ete EE ene eeae 79 USB Host Connector viii bee ba SAA le ER Hee 80 Ethernet Connector asia era soo ON OR le allena 81 Micro SD Card Connector uv eh A d IHRE Aide 82 External 5 V Power Connector 000s cece cee etn eee eens 83 Serial Connectors seriale ia dere DEEP deve had AG LENA S Rep Eas a 85 Serial Port DUART Di lai Le e uas 85 SPI Connector mii E a 86 Serial Port 1 PC2 Connector iii 87 O Block Gofhrniectot o ro A De e e bati e 88 STP26 Screw Terminal Panel sssseseeeeeeeeeee e eee e eens 91 LED Status Indicators x cea dee I e RA banda UNI ANTEA UR EAT AURA 93 DIO qc T p E C e 95 Contents About this Manual The first part of this manual describes how to install and set up your DT7837 module and verify that your module is working properly The second par
26. DATA TRANSLATION UM 26000 A DT7837 User s Manual First Edition March 2015 Data Translation Inc 100 Locke Drive Marlboro MA 01752 1192 508 481 3700 www datatranslation com Fax 508 481 8620 E mail info datx com Copyright 2015 by Data Translation Inc All rights reserved Information furnished by Data Translation Inc is believed to be accurate and reliable however no responsibility is assumed by Data Translation Inc for its use nor for any infringements of patents or other rights of third parties which may result from its use No license is granted by implication or otherwise under any patent rights of Data Translation Inc Use duplication or disclosure by the United States Government is subject to restrictions as set forth in subparagraph c 1 ii of the Rights in Technical Data and Computer software clause at 48 C F R 252 227 7013 or in subparagraph c 2 of the Commercial Computer Software Registered Rights clause at 48 C F R 52 227 19 as applicable Data Translation Inc 100 Locke Drive Marlboro MA 01752 The DT7837 software is based of the Linux open source development environment which uses the GNU General Public License Data Translation example programs may use code from other vendors This code is for demonstration purposes only If you want to use this code for commercial purposes you must ensure that you resolve any licensing issues with the appropriate parties Data Tr
27. FIFO of 2 kSamples 8 kBytes Each sample of the DT7837 is a 32 bit value The DT7837 module uses offset binary data encoding where 000000 represents negative full scale and FFFFFFh represents positive full scale Use software to specify the data encoding as binary The ADC outputs FFFFFFh for above range signals and 000000 for below range signals Error Conditions The DT7837 module will detect an overrun error if the user buffers are not being sent to the module fast enough and the A D converters run out of user buffers to fill To avoid this error try one or more of the following e Reduce the clock rate of the A D e Increase the size of the buffers e Increase the number of buffers e Close any other applications that are running 33 Chapter 2 Tachometer Input Features 34 You can connect a tachometer signal with a range of 30 V to pin 23 of the Digital connector Refer to page 27 for the pin descriptions of the Digital connector The tachometer input accepts signals with a maximum frequency of 1 MHz and a minimum pulse width of 0 4 us The threshold voltage is fixed at 2 V with 0 5 V of hysteresis To read the value of tachometer in the input stream specify bit 4 in the channel mask for the input stream You can measure the frequency or period of the tachometer input signal to calculate the rotation speed for high level 30 V tachometer input signals An internal 12 MHz counter is used for the measurement yiel
28. Port Serial port 1 and the 12C2 port are provided on the same 6 pin header Serial port 1 is a 3 3 V TTL serial interface that supports transmit and receive signals and connects to the UART1 interface of the AM3552 processor The bidirectional I C2 port connects to the IC port 2 interface of the AM3552 processor and is provided for embedded connectivity It is possible to reconfigure the pins of the I2C port 2 interface as the remaining UART 1 pins to provide the full functionality of serial port 1 Principles of Operation SPI Port The SPI Serial Peripheral Interface is provided on an additional 6 pin header for embedded connectivity This port connects to the SPI port 1 interface of the AM3552 processor GPMC Bus Interface A 16 bit address data multiplexed bus interface is supplied by the processor In addition to the NAND flash this bus also supports the FPGA All control registers for the DT7837 are accessible in the CS1 address space The CS3 address space provides access to the input FIFO Additional Signals Used on Processor The following are additional pins on the processor that are connected for use on the DT7837 module XDMAEvent0 Configured but not used XDMAEventl Used for an analog output DMA event currently not supported XDMAEvent2 Used for an analog input DMA event GPIO1_20 Configured for a DMA event but not used GPIO1_25 Configured as an interrupt but not used GPIO1_26 Configured as
29. alog input circuitry of the DT7837 module The modules support the following software programmable IEPE functions for each analog input channel e Excitation current source The DT7837 module provides an internal excitation current source of 4 mA You can turn the internal excitation current source on or off using software e Coupling type You can select whether AC coupling or DC coupling is used DT7837 modules provide 20 V compliance voltage Note If you enable the use of the internal excitation current source it is recommended that you choose AC coupling Input Resolution The resolution of the analog input channels is fixed at 24 bits you cannot specify the resolution in software Continuous Sampling Mode The DT7837 module supports continuous sampling mode on the input stream This is an asynchronous I O operation that is non blocking so that your application can perform other operations while acquisition is being performed In continuous sampling mode you can acquire data from the following channels in the input data stream analog input channels 0 to 3 the tachometer input the general purpose counter timer the measure counter and the digital input port In software you specify the channel mask for the input stream to determine which channels to sample The bits of the channel mask are as follows e Channels bits 0 to 3 Analog input channels 0 to 3 e Channel bit 4 Tachometer refer to page 34 for more
30. an interrupt but not used GPIO1_27 Configured as an interrupt but not used GPIO3_20 Configured as an interrupt but not used Digital Connector The Digital connector provides access to the tachometer input and GPIO General Purpose Input and Output signals of the DT7837 module Refer to page 77 for the pin assignments of this connector Using software you can specify a general purpose input signal as the signal source for the following destinations Digital input the default signal for each general purpose input pin External A D trigger input External D A trigger input Gate input for the general purpose counter timer C T 0 Clock input for the general purpose counter timer C T 0 27 Chapter 2 28 Using software you can specify a general purpose general purpose output signal as the signal source for one of these destinations Digital output the default signal for each general purpose output pin e Clock output for the general purpose counter timer C T 0 Note that a single general purpose input may drive several destinations at the same time However a single general purpose output can have only one driving source Principles of Operation Analog Input Features This section describes the following features of analog input A D subsystem on the DT7837 module Analog input channels described on this page Input ranges and gains described on this page IEPE functions described on page 30 I
31. anslation is a registered trademark of Data Translation Inc All other brand and product names are trademarks or registered trademarks of their respective companies Radio and Television Interference This equipment has been tested and found to comply with CISPR EN55022 Class A and EN61000 6 1 requirements and also with the limits for a Class A digital device pursuant to Part 15 of the FCC Rules These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the instruction manual may cause harmful interference to radio communications Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at his own expense Changes or modifications to this equipment not expressly approved by Data Translation could void your authority to operate the equipment under Part 15 of the FCC Rules Note This product was verified to meet FCC requirements under test conditions that included use of shielded cables and connectors between system components It is important that you use shielded cables and connectors to reduce the possibility of causing interference to radio television and other electronic devices Canadian Department of Communications Statem
32. ck bottom board of the DT7837 module I Table 21 lists the pin assignments for the Micro SD card connector on the DT7837 module 9 Card Detect Switch lao Bi 87 654 3 2 1 pe 10 Bottom View E 12 13 Figure 18 Micro SD Card Connector Table 21 Pin Assignments for the Micro SD Card Connector Connector Connector Pin Number Signal Description Pin Number Signal Description 1 DAT2 9 CD 2 DAT3 CD 10 DGND 3 CMD 11 CGND 4 3 3 V 12 CGND 5 CLK 13 CGND 6 DGND 14 CGND 7 DATO 15 CGND 8 DAT1 82 Connector Pin Assignments and LED Status Indicators External 5 V Power Connector The DT7837 module provides two connectors for attaching a 5 VDC external power supply a DIN connector and a 3 position Phoenix header Figure 19 shows the layout of the DIN power connector J6 on the ARM block bottom board of the DT7837 Figure 19 Layout of the DIN Power Connector Table 22 lists the pin assignments for the external DIN power connector on the DT7837 module Table 22 Pin Assignments for the External Power Connector Connector Connector Pin Number Signal Description Pin Number Signal Description 1 5 VDC 2 5 VDC 3 Ground 4 Ground You can connect the optional EP361 power supply to the DIN connector if desired Refer to page 72 and page 73 for detailed specifications of this power supply 83
33. ctor J8 on ARM block TE Connectivity 5499786 6 Serial connectors J12 J13 and J14 on ARM block FCI 68000 406HLF a The reference designator indicates the location of the connector on the board The ARM block is the bottom board and the I O block is the top board b The optional EP405 USB to Serial TTL cable attaches to connector J13 and the USB port of your computer Specifications External Power Supply Specifications Table 15 lists the specifications for the option EP361 5 V external power supply that is used with the DIN power connector on the DT7837 module Table 15 Specifications for the Optional EP361 External Power Supply Used with the DIN Connector on the DT7837 Module Feature Specifications Type Total Power medical power supply TPEMG24 S050400 7 Input voltage Typical 90 264 V AC Input current Typical 0 347 A at 115 V AC 0 215 A at 230 V AC Frequency 47 to 63 Hz Inrush current 6 274 A RMS at 230 V AC Output voltage 5VDC Output current 4 0A Output wattage Typical 20 24 W Noise and ripple 1 peak to peak Regulatory specifications UL ITE CE FCC Class B Energy Star compliant 73 Appendix A Table 16 lists the specifications for the external power supply that is used with the 3 position header on the DT7837 module Table 16 Specifications for the External Power Supply Used with the 3 Position Header on the DT7837 Module
34. de useful information or information that requires special emphasis cautions provide information to help you avoid losing data or damaging your equipment and warnings provide information to help you avoid catastrophic damage to yourself or your equipment Items that you select or type are shown in bold About this Manual Related Information Refer to the following documents which can be found on the DT7837 web page on our website http www datatranslation com products dataacquisition embedded DT7837 for more information on using the DT7837 module e DT7837 Getting Started help file e DT7837 File I O Programming Manual Refer to your Linux documentation for more information about Linux and Texas Instruments documentation for more information on the TI Sitara AM3352 1 GHz ARM Cortex A8 processor Where To Get Help Should you run into problems installing or using a DT7837 module the Data Translation Technical Support Department is available to provide technical assistance Refer to Chapter 4 for more information If you are outside the United States or Canada call your local distributor whose number is listed on our web site www datatranslation com 10 Overview Hardware Features iii ili RR Be we shee Tete waa 13 supported SOMWAIRS sssi csser sisi astune tere Ree De RIA REP RR 18 Supported ACCOSEOTIGS oc isan i dedu er e rer i 19 Cotos Saared PROCES Lune cete bi oe dea a eu ea Ee ve egere 21 11 Cha
35. described in Table 29 Table 29 LED Status Indicators on the DT7837 Module LED Color of the LED Status Description Input Trigger Off Idle LED Solid amber Input subsystem armed it is waiting for an external digital trigger or threshold trigger the module must have been configured for one of these trigger types Solid green Input subsystem has been triggered Output Off Idle Trigger LED si si ni Solid amber Output subsystem armed it is waiting for an external digital trigger or threshold trigger the module must have been configured for one of these trigger types Solid green Output subsystem has been triggered Power LED Off Power off Solid green Power on 93 Appendix B 94 Symbols 5 V power connector 83 84 Numerics 3 position Phoenix header 84 A accessories EP405 USB to serial TTL debug cable 19 EP406 cable 19 STP26 screw terminal panel 19 aliasing 32 AM3352 processor 25 analog input calibrating 56 channels 29 connectors 76 data format and transfer 33 error conditions 33 gain 29 IEPE functions 30 input range 29 resolution 30 sample clock 32 specifications 60 triggers 31 ARM block 25 ARM processor 25 C C T see counter timer 66 67 calibrating the module analog input subsystem 56 running the calibration utility 55 channels analog input 29 counter timer 36 digital I O 47 digital input 47 measure counter 43 tachometer 34 clien
36. ding a resolution of 83 ns 1 12 MHz You can read the number of counts between two consecutive starting edges of the tachometer input signal by including channel 4 for the DT7837 in the analog input channel list The starting edge is programmable either rising or falling Using software you can also specify a flag called Stale that indicates whether or not the data is new If the Stale flag is set as Used the default value the most significant bit MSB of the value is set to 0 to indicate new data reading the value before the measurement is complete returns an MSB of 1 If the Stale flag is set to Not Used the MSB is always set to 0 When the input operation is started the internal 12 MHz counter starts incrementing when it detects the first starting edge of the tachometer input and stops incrementing when it detects the next starting edge at that point the counter stores the count The stored count is maintained until it is read as part of the input data stream or until a new count is stored The next tachometer measurement operation is started automatically If the sample rate of the input subsystem is faster than the tachometer input frequency then the stored count retains the current value when the count is read by the input subsystem The operation of the Stale flag in this case is described as follows e If another input subsystem sample occurs before another measure completes and the Stale flag is enabled then the Stale flag
37. e correspond to digital output signals 0 to 7 Note If you assigned a general purpose input signal as a counter clock or gate input or as an external trigger you can read the value of the signal as you would any other digital input signal if desired If you want to write a value to a specific digital output line ensure that the corresponding pin of the Digital connector is not configured for another use such as the output of the counter timer or you could corrupt the signal on the pin A digital line is high if its value is 1 a digital line is low if its value is 0 On power up or reset a low value 0 is output from each of the digital output lines and a high value 1 is read from each of the digital input lines if the lines are not connected Operation Modes DT7837 modules support the following digital I O operation modes e Synchronous read and write operations Using software you can read the value of the digital input port using a synchronous read operation or write a value to the digital output port using a synchronous write operation The operation is blocking in that it does not return until the value is read or written You do not specify a trigger or clock for a synchronous read or write operation The operation stops automatically once the value is read or written e Continuous digital input Using software enter the digital input port all 8 digital input lines as specify bit 7 of the channel mask in the
38. e start trigger event occurs when the signal attached to a specified analog input channel rises above or falls below a user specified threshold value Using software you specify the following parameters Edge Specify a rising edge threshold trigger if you want to trigger when the signal rises above a threshold level or a falling edge threshold trigger if you want to trigger when the signal falls below a threshold level Threshold channel Specify any one of the analog input channels as the threshold input channel Threshold level Specify a value between 10 V for a gain of 1 or 1 V for a gain of 10 as the threshold level Note that in software this value must be entered as counts To convert raw counts to volts use the following formulas Gain of 1 volts 2 0f 10 0f counts 1 lt lt 24 10 0f Gain of 10 volts 2 0f counts 1 lt lt 24 1 0f Note The DT7837 driver sets the threshold level as close as possible to the value that you specify However the value that you specify may not be the actual value that is set You can return the actual threshold level that was set using software Input Clock Source and Sampling Frequency The DT7837 module supports an internal A D clock which is derived from the 48 MHz reference clock The reference clock is generated from the onboard oscillator Using software you specify the frequency at which to pace input operations The sampling frequency can ra
39. ent This digital apparatus does not exceed the Class A limits for radio noise emissions from digital apparatus set out in the Radio Interference Regulations of the Canadian Department of Communications Le pr sent appareil num rique n met pas de bruits radio lectriques d passant les limites applicables aux appareils num riques de la class A prescrites dans le Reglement sur le brouillage radio lectrique dict par le Minist re des Communications du Canada Table of Contents About this Manual Lei 9 Intended Audience ee ad eden bak a aria e 9 How this Manual is Organized sss 9 Conventions Used in this Manual 00 ccc cece eee teen eens 9 Related Information 2mm bie ira A La Fa se pte oae ines 10 Where To Get Help ia ini Voli nali fusti sea ac S Le Ub bros 10 Chapter 1 Overview L iii 11 Hardware Features cain Ren siete feces Yer ete Ea reb ee qe te Ie e p hea 12 Board Layout Overview 15 Supported Software Vic RT e E 18 Supported Accessories si iii NR A eee ela 19 Getting Started Procedure ne ene 21 Chapter 2 Principles of Operation eee eee 23 Block Diasrami see sara EN A a 24 ARM Block eroi ala E Ede ER C go e die 25 ARM Processor een Re Ret mnt ER eR dandi d dde ees 25 Memoty 3 siii e t deer ie Pen eb ieu e eie ps 25 Embedded NAND Flash 00 ccc cee s 25 EEPROM oie tachi Ree Wd ta Ried aa a EUR a
40. equencies greater than 10 MHz If you are using an external C T clock input source you can output pulses using a maximum frequency of 5 MHz Counter Timer Operation Modes The general purpose counter timer on the DT7837 module supports the following counter timer operation modes Event counting Rate generation Non repeatable one shot Idle The following subsections describe these modes in more detail Event Counting Use event counting mode if you want to count the number of rising edges that occur on the counter s clock input when the counter s gate signal is active low level or high level You can count a maximum of 4 294 967 296 events before the counter rolls over to 0 and starts counting again Using software you must specify the following parameters for the event counting operation Active gate type external low level or external high level Refer to page 37 for more information about the supported gate types The general purpose input pin to use for the external gate signal Ensure that you physically connect the gate signal to this input pin Refer to page 27 for the pin descriptions of the Digital connector The C T clock source internal or external Note that in event counting mode the external C T clock is more useful than an internal C T clock refer to page 37 for more information about the C T clock sources The general purpose input pin to use for the external C T clock input Ensure that you ph
41. er Passband 3 dB Passband ripple 0 005 dB Stopband 100 dB 0 49 x sample frequency Hz 0 453 x sample frequency Hz 0 547 x sample frequency Hz Analog filter Low pass cutoff 3 dB High pass cutoff 3 dB AC coupling 400 kHz 0 1Hz Channel to channel crosstalk Input Signal 1 kHz 121 dB with 50 Q termination Input impedance 1 MQ Il 20 pF Coupling AC DC software selectable per channel IEPE current source 4 mA 0 5 IEPE compliance voltage 24V IEPE current source noise DC to 1 kHz 5 nARMS 60 Specifications Table 4 Analog Input Subsystem Specifications cont Feature DT7837 Specifications DC Accuracy Offset error 1 mV Offset error temperature coefficient 7 2 uV C Gain 100 uV C Gain error Gain of 1 0 02 Gain of 10 0 5 Gain error temperature coefficient 50 ppm C ADC Integral Non Linearity error INL 0 0006 of full scale range ADC Differential Non Linearity error DNL Monotonic to 24 bits Dynamic Performance Gain of 1 Gain of 10 Effective Number of Bits ENOB 1 kHz input 105 5 KSPS 1 dBFS input 15 bits 15 bits 6 dBFS input 16 bits 16 bits Signal to Noise and Distortion Ratio SINAD9 1 kHz input 105 5 kSPS 1 dBFS input 93 dB 93 dB 6 dBFS input 92 dB 92 dB Signal to Noise Ratio SNR 1 kHz input 105 5
42. ero che ede 25 Micto SB Card iste o on Sh antro ia 26 USB Device Client Port EAE r AEE cc AENEA OT rr 26 USB Host Pott a eed RR Pee bebe ed dda ended wate tides 26 SertaliBoEt 0 xd sacs deste ari Ra 26 Serial Port 1 72 C2 POL ace oret oe DNUS aed Ee ia te 26 SPI Port ee tte whee ead Se ERR PRS AAA Dub qur eg eid eer ea as 27 GPMC B s Interface vei sa eh en ba Doe e ev ae eto tete a ns oaa 27 Additional Signals Used on Processor L eee 27 Digital Connector on rte EE EET ere HERE celer ion 27 Analog Input Features sions 23 sell Ge Ere e i t e e ale e tres 29 Analog Input Channels ra perdete e aie ose itr ete onde et a 29 Input Ranges and Gains LL 29 IERE Funcionss Mieco ioe hens IW hee e UU DUE VERGI MOINES S 30 Input Resolution tic ino iban abba hs 30 Continuous Sampling Mode rr 30 Input Triggers os odore tX ea EP Has Vl DEN oR Oe pes 31 Input Clock Source and Sampling Frequency L rr 32 Data Format and lransfer repere laedere e Late rtc he e y 33 Contents Error Conditions A ia 33 Tachometer Input Features 34 General Purpose Counter Timer Features L rr 36 G IChannels visti not O Dd KA Na e tia a A SONAS 36 G T Clock Input Sources rr acanto ei Dee pega esenti 37 Gate Iypes iios sace nale ale ea rele e e Edd pede dat 37 Pulse Output Period Pulse Width and Polarity LL mo 38 Counter Timer Operation Modes
43. h general purpose input pin External A D trigger input Gate input for the general purpose counter timer C T 0 Clock input for the general purpose counter timer C T 0 Using software you can specify a general purpose output signal as the signal source for one of these destinations Digital output the default signal for each general purpose output pin e Clock output for the general purpose counter timer C T 0 Note that a single general purpose input may drive several destinations at the same time However a single general purpose output can have only one driving source Connector Pin Assignments and LED Status Indicators USB Device Client Connector Figure 15 shows the layout of the USB device client connector J4 on the ARM block bottom board of the DT7837 module This is a type B connector Figure 15 Layout of the USB Type B Connector for the USB Device Client Port Table 18 lists the pin assignments for the USB type B connector on the DT7837 module for the USB device client port Table 18 Pin Assignments for the USB Type B Connector for the USB Device Client Port Connector Connector Pin Number Signal Description Pin Number Signal Description 1 USB 5 V 3 USB Data 2 USB Data 4 USB Ground Note The outer shell provides cable shield to chassis ground 79 Appendix B USB Host Connector Figure 15 shows the layout of the USB host connector
44. hannels analog input channels 0 and 1 and the digital input port When the start trigger is detected samples from the specified channels are acquired continuously Chan 7 Chan 7 Chan 7 Chan 7 Chan 7 Chan 7 Chan 1 Chan 1 Chan 1 Chan 1 Chan 1 Chan 1 Chan 0 Chan 0 Chan 0 Chan 0 Chan 0 Chan 0 Pre trigger data acquired mi Start Trigger occurs Figure 8 Continuous Sampling Mode on the DT7837 Module Input Triggers A trigger is an event that occurs based on a specified set of conditions For continuous sampling mode of the channels in the input data stream described on page 30 you must specify a start trigger to start acquisition The DT7837 module supports the following sources for the start trigger you configure the trigger source and its parameters using software Software trigger A software trigger event occurs when you start the analog input operation the computer issues a write to the module to begin conversions Using software specify the start trigger source as a software trigger e External digital TTL trigger An external digital TTL trigger event occurs when the module detects a rising or falling edge transition on the signal connected to a general purpose input pin on the Digital connector Refer to page 27 for more the pin descriptions of the Digital connector You can specify which edge is active using software Chapter 2 32 Threshold trigger Th
45. he pulse width of the output pulse 41 Chapter 2 42 e The general purpose output signal to use for the C T clock output signal Ensure that you physically connect the C T output signal to this output pin Refer to page 27 for the pin descriptions of the Digital connector e The polarity of the output signal active high or active low Refer to page 38 for more information on the polarity of the output pulse e Retriggerable setting of 0 for non repeatable one shot Refer to page 41 for an example of connecting a non repeatable one shot application Idle Mode If you use idle mode the counter no longer drives the clock output signal that is assigned to one of the general purpose output signals pins 11 to 18 of the Digital connector Note The value of the counter output signal can also be overwritten by writing to the digital output subsystem If you assigned a general purpose input signal as a counter clock or gate input or external trigger you can read the value of the signal as you would any other digital input signal Refer to page 47 for more information on digital I O operations Principles of Operation Measure Counter Features DT7837 modules provides one measure counter Using this counter you can measure the frequency period or pulse width of a single signal or the time period between two signals and return the value in the analog input stream This is useful for correlating the analog input data
46. ied gate edge is detected until you stop the operation You can use this mode to clean up a poor clock input signal by changing its pulse width and then outputting It Gate Signal is Ignored y Gate Input High GL TL TUL Output Pulses You can determine period pulse width and polarity of the output pulse using software Figure 11 Non Repeatable One Shot Mode Using software you must specify the following parameters for the non repeatable one shot operation Active gate type that enables the operation Refer to page 37 for more information about the supported gate types The general purpose input pin to use for the external gate signal Ensure that you physically connect the gate signal to this input pin Refer to page 27 for the pin descriptions of the Digital connector The C T clock source internal or external that generates the pulse Note that in one shot mode the internal C T clock is more useful than an external C T clock refer to page 37 for more information about the C T clock sources The general purpose input pin to use for the external C T clock input Ensure that you physically connect the clock input signal to this input pin Refer to page 27 for the pin descriptions of the Digital connector The period of the output pulse Refer to page 38 for more information about the period of the output pulse The pulse width duty cycle of the active pulse Refer to page 38 for more information about t
47. iemgssuesasseangsgdass8sHdisds38 morounu ngsgumgRHRRARduma smusgeegeunanmnco amp BoHRoOKkRSUSESE5SsabasagBH amp SHd4ds5g Figure 25 I O Block Connector J9 88 Connector Pin Assignments and LED Status Indicators Table 27 lists the pin assignments of the I O block connector on the DT7837 module on both the ARM block and the I O block Table 27 Pin Assignments for the I O Block Connector J9 Connector Connector Pin Number Signal Description Pin Number Signal Description 1 5 V 2 5 V 3 5 V 4 5 V 5 Ground 6 Ground 7 Ground 8 Ground 9 Test 0 10 Test 1 11 Test 2 12 Test 3 13 LEDO 14 LED 1 15 LED 2 16 LED 3 17 LED 4 18 LED 5 19 LED 6 20 LED7 21 DC DC Sync 0 22 DC DC Sync 1 23 Ground 24 Ground 25 IPC SLC O 26 IPC SLC 1 27 IC SDA O 28 IC SDA 1 29 Ground 30 Ground 31 Write Enable 0 32 Write Enable 1 33 Read Enable 0 34 Read Enable 1 35 In Sync Control 0 36 In Sync Control 1 37 In Sync Control 2 38 In Sync Control 3 39 Ground 40 Ground 41 DAQ Clock 0 42 DAQ Clock 1 43 DAQ Clock 2 44 DAQ Clock 3 45 Ground 46 Ground 47 Sync 0 48 Sync 1 49 Data Clock 0 50 Data Clock 1 51 Data Clock 2 52 Data Clock 3 53 Ground 54 Ground 55 In Serial Data 0 56 In Serial Data 1 57 In Serial Data 2 58 In Serial Data 3 89 Appendix B Table 27 Pin Assignments for the I O Block Connector J9
48. information e Channel bit 5 Counter timer 0 refer to page 36 for more information e Channel bit 6 Measure counter refer to page 43 for more information Channel bit 7 Digital input port refer to page 47 for more information The trigger that starts acquisition for the channels in the input stream can be any of the supported start trigger sources Refer to page 31 for more information about the start trigger sources However the input stream of the module must be armed using software before the module can detect the trigger condition Principles of Operation Input Sample Clock If a software trigger is specified as the start trigger acquisition starts immediately when the software start command is executed Otherwise acquisition begins when the specified trigger signal is detected When it detects the specified start trigger the module simultaneously acquires data from all of the channels in specified in the input stream Acquisition repeats continuously until you stop the operation The conversion rate is determined by the sampling frequency refer to page 32 for more information When you stop the operation using software the DMA engine stops and no further data is collected It is the programmer s responsibility to clean up all inprocess control block resources To restart the operation the input stream of the module must be armed and started again Figure 8 illustrates continuous acquisition mode using three c
49. input stream You can specify the sampling frequency and trigger source for the input stream The trigger starts the acquisition The input sample clock paces the acquisition of data from the digital input port as well as the analog input channels tachometer input general purpose counter timer and or the measure counter 47 Chapter 2 48 Triggering Acquisition on Multiple Modules The internal clock on the DT7837 module is derived from the 48 MHz crystal oscillator and provides the timing for the analog input subsystem on the module You can start acquisition on multiple modules by connecting all modules to a shared external trigger input as shown in Figure 12 Using software you must define one of the general purpose input pins on the Digital connector on each DT7837 module as the external trigger signal When triggered the modules start acquiring data at the same time Using this connection scheme the measurements of one module are not synchronous with the measurements of another module as they do not share the same reference clock Device Under Test DT7837 External Inputs 1 Trigger DT7837 Inputs gt gt 2 DT7837 Inputs n Figure 12 Triggering Multiple Modules Using an External Trigger Source TECOS a ile er poi It Your Module Needs Factory Service iis eissese eee eme e e ae ena 49 Chapter 3 Technical Support Should you
50. kSPS 1 dBFS input 97 dB 97 dB 6 dBFS input 96 dB 96 dB Total Harmonic Distortion THD 1 kHz input 105 5 kSPS 1 dBFS input 102 dB 102 dB 6 dBFS input 100 dB 101 dB Spurious Free Dynamic Range SFDR 1 kHz input 105 5 KSPS 1 dBFS input 97 dBFS 98 dBFS 6 dBFS input 103 dBFS 102 dBFS Noise Floor 50 Q input termination 105 5 kSPS 56 uVRMS 65 uVRMS Overvoltage Protection Overvoltage protection Power on 40 V to 20 V Power off 40 V ESD protection Arc 8 kV Contact 4 kV t an o The total frequency response is the combined frequency response of the ADC Delta Sigma filter and the analog filter Channel 0 is the reference channel with a 20 Vpp signal and a maximum sample rate of 105 469 kSamples s Cable capacitance of 30 pF per foot typical must be added Offset errors are referred to the input 61 Appendix A 62 ENOB SINAD SNR THD and SFDR measurements were made with a 16384 point FFT with a minimum 4 term Blackman Harris window Effective Number of Bits ENOB is calculated from the SINAD value with adjustment for level below full scale of the input signal SINAD 1 76 IBFS ENOB 6 02 where IBFS is a positive value in dB representing the ratio of a full scale signal to the input signal Signal to Noise and Distortion SINAD is the ratio of the RMS value of the input signal to the RMS sum of all other spectral components excluding
51. les s to 105 469 kSamples s Input range of 10 V with software selectable gains of 1 and 10 for an effective input range of 10 V and 1 V Continuous acquisition from multiple analog input channels simultaneously Supports the ability to return the value of the tachometer general purpose counter timer measure counter and or digital input port in the analog input data stream allowing you to measure a variety of signals synchronously with analog input measurements Software programmable trigger source software trigger external trigger or threshold trigger using any analog input channel to start acquisition Accounts for analog input group delay in hardware and allows user specified trigger delay to account for analog output group delay Up to eight TTL digital input lines using the eight general purpose inputs You can read the digital input port directly or you can return the value of the digital input port in the input data stream Up to eight TTL digital output lines using the eight general purpose outputs You can write a value to the digital output port directly One 32 bit general purpose counter timer for performing event counting rate generation and non repeatable one shot operations You can use two general purpose input signals for the C T clock and gate inputs and one general purpose output signal for the C T clock output You can read the value of the counter timer directly or through the inp
52. lowing Frequency between the start and stop signals edges You can calculate the frequency as follows Frequency 48 MHz Number of counts 1 where 48 MHz is the internal measure counter frequency For example if the count is 201 the measured frequency is 240 kHz 48 MHz 200 Period between the start and stop signals edges You can calculate the period as follows Period 1 Frequency Period Number of counts 1 48 MHz where 48 MHz is the internal measure counter frequency 45 Chapter 2 e Pulse width of the start and stop signal edges rising to falling edge or falling edge to rising edge You can calculate the period as follows Pulse width 1 Frequency Pulse width Number of counts 1 48 MHz where 48 MHz is the internal measure counter frequency 46 Principles of Operation Digital I O Features This section describes the following features of digital I O operations Digital I O lines Operation modes Digital I O Lines DT7837 modules support one digital input port consisting of up to 8 digital input lines lines 0 to 7 and one digital output port consisting of up to 8 digital output lines lines 0 to 7 The resolution is fixed at 8 bits By default general purpose input pins 1 to 8 of the Digital connector on the DT7837 module correspond to digital input signals 0 to 7 Similarly general purpose output pins 11 to 18 of the Digital connector on the DT7837 modul
53. m select 1 Manually calibrate an analog input channel Enter the number 0 to 3 of the analog input channel that you want to calibrate Enter the gain value 1 or 10 to calibrate for the analog input channel Enter 0 to calibrate the offset potentiometer or 1 to calibrate the gain potentiometer Enter 0 to calibrate the selected potentiometer for sampling frequencies less than or equal to 52734 Hz or 1 to calibrate the selected potentiometer for sampling frequencies greater than 52734 Hz The current calibrations selections are displayed If the current selections are correct enter Y To fix an entry enter N to repeat these steps If you chose to calibrate the offset potentiometer in step 4 adjust the potentiometer as follows a Verify that 0 0000 V is applied to the channel that you want to calibrate b Adjustthe value to 0 0000 V by typing a value between 0 and 255 or by pressing the or key c Press Enter to display the current information for the channel including the value of the potentiometer and the current reading d Repeat steps 7b and 7c until the reading is calibrated to 0 0000 V e Once calibrated press x to exit to the main menu If you chose to calibrate the gain potentiometer in step 4 and selected a gain of 1 in step 3 adjust the potentiometer as follows Verify that 49 375 V is applied to the channel that you want to calibrate b Adjust the value to 49 375 V by typing a value between 0 and 255
54. m sample rate is slower than the selected measurement period then a new count value is stored as each period measurement completes When an input subsystem sample occurs the most recently stored measure count is written into the input data stream A data pipeline is used in the hardware to compensate for the A D group delay and synchronizes the value of the measure counter with the analog input measurements so that all measurements are correlated in time The measure counter is treated like any other channel in the analog input channel list therefore all the triggering and conversion modes supported for analog input channels are supported for the measure counter When you read the value of the measure counter as part of the analog input data stream you might see results similar to the following An Example of Reading a Measure Counter as Part of the Analog Input Data Stream Measure Counter Time AID Value Values Status of Operation 10 5002 0 Operation started but is not complete 20 5004 0 Operation not complete 30 5003 0 Operation not complete 40 5002 12373 Operation complete 50 5000 12373 Next operation started but is not complete 60 5002 12373 Operation not complete 70 5004 12373 Operation not complete 80 5003 14503 Operation complete 90 5002 14503 Next operation started but is not complete Using the count that is returned from the measure counter you can determine the fol
55. nal or external Refer to page 37 for more information about the C T clock sources If you are using an external C T clock source the general purpose input pin to use for the external C T clock input Ensure that you physically connect the clock input signal to this input pin Refer to page 27 for the pin descriptions of the Digital connector The period of the output pulse Refer to page 38 for more information about the period of the output pulse The pulse width duty cycle of the active pulse Refer to page 38 for more information about the pulse width of the output pulse The general purpose output signal to use for the C T clock output signal Ensure that you physically connect the C T output signal to this output pin Refer to page 27 for the pin descriptions of the Digital connector The polarity of the output signal active high or active low Refer to page 38 for more information on the polarity of the output pulse Refer to page 40 for an example of connecting a rate generation application Principles of Operation Non Repeatable One Shot Use non repeatable one shot mode to generate a single output pulse from the counter whenever the specified edge is detected on the counter s gate signal after the pulse period from the previous output pulse expires Any gate signals that occur while the pulse is being output are not detected by the module as shown in Figure 11 The module continues to output a pulse when the specif
56. nals from the Digital connector on the DT7837 module and provides digital output and C T clock output signals from the Digital connector on the module The 26 pin 36 inch EP406 cable is included with the STP26 screw terminal panel The cable allows you to attach the STP26 screw terminal panel to the Digital connector on a DT7837 module Figure 4 shows the STP26 and EP406 cable Figure 4 STP26 Screw Terminal Panel and EP406 Cable EP405 USB to Serial TTL Debug Cable This 3Mbaud 1 8 m cable shown in Figure 5 connects the USB port of the host computer to serial UART connector J13 on the DT7837 allowing you to debug the DT7837 using a terminal interface Figure 5 EP405 USB to Serial TTL Debug Cable 19 Chapter 1 20 e EP361 External Power Supply This 5 VDC optional power supply and cable shown in Figure 6 connects to the DIN power connector on the DT7837 module and to the wall power outlet Figure 6 EP361 5 VDC External Power Supply Overview Getting Started Procedure Refer to the DT7837 Getting Started help file on our web site http www datatranslation com products dataacquisition embedded DT7837 for getting started information 21 Chapter 1 22 Principles of Operation o nre Eee E aaa ia 24 Analog Input Peah ss racista 29 airea e a A E E iaia 34 General Purpose Counter Timer Features 0 0 0 5 iii 36 Measure Counter Peatutes ii ie cd 43 Digital 17O Featues ici
57. nge from 195 3125 Hz to 105 469 KHz Note According to sampling theory Nyquist Theorem specify a frequency that is at least twice as fast as the input s highest frequency component For example to accurately sample a 20 KHz signal specify a sampling frequency of at least 40 kHz to avoid aliasing The DT7837 driver sets the sampling frequency as close as possible to the value that you specify However the value that you specify may not be the actual value that is set You can return the actual sampling frequency that was set using software Once the sample clock is started the module requires 39 conversions before the first A D sample is valid The valid sample is aligned with the start trigger Principles of Operation Note After changing the A D master clock wait a few milliseconds for the master clock to settle before calibrating the module or performing an acquisition The DT7837 module has two power modes low power mode and high power mode Low power mode is used when you specify a sampling frequency less than 52 734 kHz High power mode is used when you specify a sampling frequency greater than or equal to 52 734 KHz If you change the power mode from low to high power or from high power to low power and then configure the device the module is self calibrated You may notice that it takes time after the device is configured to complete the calibration process Data Format and Transfer The DT7837 has an input
58. nments for the Digital Connector Connector Connector Pin Number Signal Description Pin Number Signal Description 1 General Purpose Input 0 14 General Purpose Output 3 2 General Purpose Input 1 15 General Purpose Output 4 3 General Purpose Input 2 16 General Purpose Output 5 4 General Purpose Input 3 17 General Purpose Output 6 5 General Purpose Input 42 18 General Purpose Output 7 6 General Purpose Input 5 19 Digital Ground 7 General Purpose Input 6 20 Digital Ground 8 General Purpose Input 7 21 Event Out currently not supported 9 Digital Ground 22 Digital Ground 10 Digital Ground 23 Tachometer input 11 General Purpose Output 0 24 Digital Ground 12 General Purpose Output 1 25 5 V 13 General Purpose Output 2 26 Digital Ground a The input signals are 5 V tolerant and 22 kQ pull ups are provided By default they are configured as digital input signals By default these signals are configured as digital input signals b The output signals are driven by LVTTL buffers and are capable of providing up to 24 mA of drive current at standard LVTTL levels By default they are configured as digital output signals By default these signals are configured as digital output signals 77 Appendix B 78 Using software you can specify a general purpose input signal as the signal source for the following destinations Digital input the default signal for eac
59. nput logic load High input voltage Low input voltage Low input current Input termination 1 LVTTL 2 0 V minimum 0 8 V maximum 0 8 mA maximum 22kQ Clocked with sample clock Yes if the C T is included in the input data stream channel bit 5 a The integrity of the signal degrades at frequencies greater than 10 MHz 67 Appendix A 68 Trigger Specifications Table 10 lists the specifications for the triggers on the DT7837 module Feature Table 10 Trigger Specifications DT7837 Specifications Trigger sources Internal software trigger External digital trigger Threshold trigger Software initiated Software selectable general purpose inputs 0 to 7 on the Digital connector Software selectable analog inputs 0 to 3 External trigger digital Trigger type Input type Input termination Voltage threshold Voltage threshold Minimum pulse width high low Overvoltage protection Edge sensitive rising or falling edge trigger software selectable 3 3 V high speed CMOS Schmitt trigger 5 V tolerant 22 1 kQ pull up resistor to 3 3 V 2 0V 0 8 V 250 ns 30 V Threshold trigger Trigger type Threshold level Hysteresis Rising or falling edge threshold trigger on any analog input channel software selectable 10 V to 10 V gain of 1 1 V gain of 10 100 mV Trigger delay 1 conversion period maximum Specifications
60. nput resolution described on page 30 Continuous sampling mode described on page 30 Input triggers described on page 31 Input sample clock source and sampling frequency described on page 32 Data format and transfer described on page 33 Error conditions described on page 33 Analog Input Channels The DT7837 module provides four analog input channels channels 0 to 3 These are single ended channels you can connect IEPE sensors to these inputs if desired refer to page 30 for more information on IEPE functions Note To maintain simultaneous operation all analog input connections on the DT7837 module must have the same lead lengths The DT7837 module uses four Delta Sigma 24 bit ADCs that provide anti aliasing filters based on the clock rate These filters remove aliasing which is a condition where high frequency input components erroneously appear as lower frequencies after sampling Using software you can specify which analog input channels to sample by specifying bits 0 to 3 in the channel mask for the input stream Input Ranges and Gains The DT7837 module provides an input range of 10 V and software selectable gains of 1 and 10 This provides effective input ranges of 10 V when the gain is 1 and 1 V when the gain is 10 29 Chapter 2 30 IEPE Functions Applications that require accelerometer vibration noise or sonar measurements often use IEPE sensors IEPE conditioning is built in to the an
61. nue Verify that 0 0000 V is applied to the channel that you want to calibrate Adjust the value to 0 0000 V by typing a value between 0 and 255 or by pressing the or key Verify that 9 3750 V is applied to the channel that you want to calibrate Adjust the value to 9 3750 V by typing a value between 0 and 255 or by pressing the or key Verify that 40 9375 V is applied to the channel that you want to calibrate Adjust the value to 40 9375 V by typing a value between 0 and 255 or by pressing the or key Repeat steps 2 through 8 for the remaining analog input channels on the module When you have finished calibrating the module press X from the main menu to exit from the program Calibration Using the Manual Calibration Procedure The DT7837 has two gains 1 and 10 and two power modes low power mode and high power mode Low power mode is calibrated when you specify a sampling frequency less than 52 734 kHz High power mode is calibrated when you specify a sampling frequency greater than 52 734 kHz Ensure that you calibrate each analog input channel for gains of 1 and 10 if you are using both gains and for both high and low power mode if you are using sampling frequencies below and above 52 734 kHz By default this utility uses DC coupling with the current source disabled To manually calibrate the analog input circuitry do the following for each channel 1 gy Pp M From the main menu of the progra
62. o kl pU RR en 47 Triggering Acquisition on Multiple Modules 0 0 ccc eee eee eee eee 48 23 Chapter 2 24 Block Diagram Serial UART Ethernet 10 100 USB 2 0 Host USB 2 0 Client SD Card The DT7837 is an open source Linux computing platform with a high accuracy dynamic signal analyzer front end The DT7837 consists of two boards The bottom board is the ARM block which includes the ARM processor PC and embedded connectivity options and memory as well as the digital I O counter timer measure counter and tachometer circuitry The top board is the I O block which includes four 24 bit IEPE analog inputs and one 24 bit stimulus analog output Note The analog output circuitry is currently not supported in software Figure 7 shows a block diagram of the DT7837 module DT7837 Block Diagram ARM Block I O Block GPMC Expansion Bus Bus Four 24 Bi ER DRAM Ania lt IEPE Inputs 512 MB DDR3 A y lt gt NAND Flash 2GB 24 Bit Stimulus D A Output Waveform TI FPGA Output AM335x ARM Cortex A8 FIFOS Tachometer 26 Pin Digital Connec GPIO Signals 8 DI 8 DO t Measure Counter Clock Generators Power Supply 5 VDC Ext Trigger Input Voltage Regulators rigg P Currently not supported in software Figure 7 Block Diagram of the DT78
63. on complete 50 5000 12373 Next operation started but is not complete 60 5002 12373 Operation not complete 70 5004 12373 Operation not complete 80 5003 14503 Operation complete 90 5002 14503 Next operation started but is not complete Using the count that is returned from the tachometer input you can determine the following e Frequency of a signal pulse the number of periods per second You can calculate the frequency as follows Frequency 12 MHz Number of counts 1 where 12 MHz is the internal counter timer clock frequency Period of a signal pulse You can calculate the period as follows Period 1 Frequency Period Number of counts 1 12 MHz where 12 MHz is the internal counter timer clock frequency For example if the count is 21 the measured frequency is 600 KHz 12 MHz 20 35 Chapter 2 General Purpose Counter Timer Features This section describes the following features of counter timer C T operations C T chamnels described below C T clock sources described on page 37 Gate types described on page 37 Pulse output period and duty cycle described on page 38 C T operation modes described on page 39 C T Channels DT7837 modules provide one 32 bit general purpose counter timer C T 0 As shown in Figure 9 the counter timer accepts a clock input and gate input signal and outputs a pulse clock output signal Using software you define general purpose I O
64. on the DT7837 Module Connector Pin Number Signal Description 1 DGND 2 Not Connected 3 Not Connected 4 UARTO_RX 5 UARTO_TX 6 Not Connected SPI Connector Figure 15 shows the layout of the SPI connector J12 on the ARM block bottom board of the DT7837 module 1 6 MIO O O Figure 23 Layout of SPI Connector J12 Table 25 lists the pin assignments for the SPI connector on the DT7837 module Table 25 Pin Assignments for SPI Connector J12 on the DT7837 Module Pin Number Signal Description 1 SPI1_DO SPI1_SCLK SPI1 CSO SPI1 D1 DGND oOo a AJ wl vy 3 3 V 86 Connector Pin Assignments and LED Status Indicators Serial Port 1 12C2 Connector Figure 15 shows the layout of the Serial port 1 12C2 connector J14 on the ARM block bottom board of the DT7837 module 1 6 OO LGUT Figure 24 Layout of Serial Port 1 12C Port J14 Table 26 lists the pin assignments for the Serial port 1 PC connector on the DT7837 module Table 26 Pin Assignments for Serial Port 1 12C Connector J14 on the DT7837 Module Pin Number Signal Description 1 UART1_RX 2 UART1_TX 3 12C2_SDA 4 12C2_SCL 5 DGND 6 3 3 V 87 Appendix B I O Block Connector Figure 15 shows the layout of the I O block connector J9 on the DT7837 module 114 116 Nw o0wo9805g5mHmaxumumsus5uHnocqgsusmpmunxanacdgstgem mur
65. or by pressing the or key Press Enter to display the current information for the channel including the value of the potentiometer and the current reading d Repeat steps 8b and 8c until the reading is calibrated to 49 375 V e Pressxto exit to the main menu 57 Chapter 4 9 Ifyou chose to calibrate the gain potentiometer in step 4 and selected a gain of 10 in step 3 adjust the potentiometer as follows a Verify that 0 9375 V is applied to the channel that you want to calibrate b Adjust the value to 0 9375 V by typing a value between 0 and 255 or by pressing the or key c Press Enter to display the current information for the channel including the value of the potentiometer and the current reading d Repeat steps 9b and 9c until the reading is calibrated to 0 9375 V e Press x to exit to the main menu 10 Repeat these steps for each gain and sampling frequency for the selected channel 11 Repeat these steps for each analog input channel 12 When you have finished calibrating the module press X from the main menu to exit from the program Restoring Factory Calibration Settings If you wish you can restore the analog input calibration values for each channel to their original factory settings by selecting 3 Restore all analog input factory calibration settings from the main menu of the DT7837 Calibration Utility A prompt is displayed to inform that the values were reset 58 m
66. pter 1 Hardware Features The DT7837 module is an open source Linux computing platform with a high accuracy dynamic signal analyzer front end making it ideal for embedded applications that require noise vibration and acoustic measurements The module is composed of two boards the bottom board contains the ARM block and the top board contains the I O block that connect together as show in Figure 1 Users can embed the module into their own enclosure and or system as needed Figure 1 DT7837 Module The key features of the DT7837 module are as follows e Open source computing platform featuring a TI Sitara AM3352 1 GHz ARM Cortex A8 processor e Linux distribution consisting of a Linux kernel bootloader and file system with a DT7837 device driver USB device client driver and USB host driver e Ethernet 10 100 Mbps connectivity to a host computer e USB 2 0 full speed connectivity to a host computer 12 Overview USB 2 0 host connection to external devices such as a mouse keyboard or external storage devices Analog input subsystem Four single ended analog input channels available through SMA connectors Four simultaneous sampling Delta Sigma 24 bit analog to digital converters ADCs Support for IEPE Integrated Electronic Piezoelectric inputs including use of a4mA current source with 20 V compliance voltage for AC or DC coupling Programmable throughput rate from 195 3125 Samp
67. t 3 pin 4 of the Digital connector By default this is digital input 3 Digital input 4 falling edge or rising edge Connect a digital input external A D trigger C T clock input or C T gate input to general purpose input 4 pin 5 of the Digital connector By default this is digital input 4 Digital input 5 falling edge or rising edge Connect a digital input external A D trigger C T clock input or C T gate input to general purpose input 5 pin 6 of the Digital connector By default this is digital input 5 Digital input 6 falling edge or rising edge Connect a digital input external A D trigger C T clock input or C T gate input to general purpose input 6 pin 7 of the Digital connector By default this is digital input 6 Digital input 7 falling edge or rising edge Connect a digital input external A D trigger C T clock input or C T gate input to general purpose input 7 pin 8 of the Digital connector By default this is digital input 7 43 Chapter 2 e A flag called Stale indicating whether or not the data is new This flag is used only when the start edge and the stop edge is set to use the same pin and edge If the Stale flag is set as Used the default value the most significant bit MSB of the value is set to 0 to indicate new data reading the value before the measurement is complete returns an MSB of 1 If the Stale flag is set to Not Used the MSB is always se
68. t Stud Client Port Figure 2 Layout of the ARM Block of the DT7837 Module 16 Overview HLLLLLLLLLLIM munis AN Gi sd Output Trigger LED bottom Input Trigger LED top Analog Input Connectors Analog Output Connector analog output currently not supported in software Figure 3 Layout of the I O Block of the DT7837 Module 17 Chapter 1 Supported Software The following software is available for use with the DT7837 module e DT7837 File I O Commands A set of commands in Linux user space for opening a subsystem or stream configuring a subsystem or stream acquiring data in the input stream reading or updating the digital I O port and or writing values to the calibration potentiometers Numerous example programs are provided to illustrate how to use these commands Refer to the DT7837 File I O Programming Manual for more information e DT7837 Kernel Device Driver The device driver resides in the Linux kernel and is responsible for performing the functions defined by the DT7837 file I O commands on the DT7837 module e DT7837 Calibration Utility This utility described in Chapter 4 allows you to calibrate the analog circuitry of the DT7837 module 18 Overview Supported Accessories The following optional accessories are available for a DT7837 module e STP26 screw terminal panel This screw terminal panel accepts tachometer digital input C T gate input and C T clock input sig
69. t of this manual describes the features of the DT7837 module and how to program the DT7837 module using Linux system calls Troubleshooting information is also provided Intended Audience This document is intended for engineers scientists technicians or others responsible for using and or programming a DT7837 module for data acquisition operations in the Linux operating system It is assumed that you have some familiarity with data acquisition principles and that you understand your application How this Manual is Organized This manual is organized as follows Chapter 1 Overview describes the major features of the DT7837 module as well as the supported software and accessories for the module Chapter 2 Principles of Operation describes all of the features of the DT7837 module Chapter 3 Troubleshooting provides information that you can use to resolve problems with the DT7837 module should they occur Chapter 4 Calibration describes how to calibrate the analog circuitry of the DT7837 module Appendix A Specifications lists the specifications of the DT7837 module Appendix B Connector Pin Assignments and LED Status Indicators lists the pin assignments of the connectors on the DT7837 module and describes the LED status indicators on the DT7837 module An index completes this manual Conventions Used in this Manual The following conventions are used in this manual Notes provi
70. t port USB 26 Index clock sources analog input 32 counter timer 37 connectors 5 V power 83 analog input 76 digital 77 Ethernet 81 I O block 88 12C2 87 micro SD card 82 serial 85 serial port 0 85 serial port 1 87 SPI 86 USB client 79 USB host 80 conversion rate 31 counter timer channels 36 clock sources 37 gate types 37 specifications 67 subsystem specifications 66 counting events 39 coupling type 30 current source 30 customer service 51 D data encoding 33 data format and transfer input data 33 DDR3 memory 25 digital connector 27 77 digital I O operations continuous digital input 47 lines 47 synchronous read 47 synchronous write 47 digital trigger 31 DIN power connector 83 DT7837 Calibration Utility 18 duty cycle 38 95 Index 96 E EEPROM 25 embedded NAND flash 25 encoding data 33 environmental specifications 70 EP405 USB to serial TTL debug cable 19 EP406 cable 19 errors analog input 33 Ethernet connector 81 event counting 39 excitation current source 30 external clock 37 external digital trigger 31 F factory service 51 file I O commands 18 flash 25 formatting input data 33 FPGA 27 frequency analog input operations 32 external C T clock 37 G gain 29 gate type 37 generating one shot pulses 41 generating pulses 40 GMPC bus interface 27 group delay 32 H host port USB 26 j I2C2 connector 26 87 idle mode 42 IEPE features 30 input channels 29
71. t to 0 When the selected start edge is the same as the selected stop edge the internal 48 MHz counter starts incrementing when it detects the first start edge of the selected input signal and stops incrementing when it detects the selected stop edge which is the same as the start edge in this case at that point the counter stores and resets the count The stored count is maintained until it is read as part of the input data stream or until a new count is stored Since the stop edge is the same as the start edge in this case the stop edge for the current measurement is the start edge for the next measurement therefore no waveform periods are missed The value of the measure count depends on the input subsystem sample frequency described as follows e If the input subsystem sample frequency is faster than the selected input frequency then the stored measure count retains the current value when it is read by the input subsystem The operation of the Stale flag in this case is described as follows If another input subsystem sample occurs before another measure completes and the Stale flag is used then the Stale flag is set and the stale measure count is written into the input data stream If another input subsystem sample occurs before another measure completes and the Stale flag is not used then the Stale flag is not set and the stale measure count is written into the input data stream e If the input subsystem sample frequenc
72. ter input is used for the starting edge and stopping edge Start and stop signals edges A D conversion complete Tachometer input falling or rising edge Digital inputs O to 7 falling or rising edge C T O Clock input falling or rising edge C T O Gate input falling or rising edge Clocked with sample clock Yes if the measure counter is included in the input data stream channel bit 6 a Limited by signal integrity and input signal conditioning Specifications General Purpose Counter Timer Specifications Table 7 lists the specifications for the general purpose counter timer C T 0 on the DT7837 module Table 9 General Purpose Counter Timer Specifications Feature Specifications Number of general purpose counter timers Clock sources Internal External 48 MHz reference clock General purpose inputs 0 to 7 on the Digital connector Gate sources Internal External Software General purpose inputs 0 to 7 on the Digital connector Counter timer outputs General purpose outputs 11 to 18 on the Digital connector Resolution 32 bits per channel Clock divider Minimum 2 Maximum 4 294 967 296 Clock output Minimum 0 0112 Hz Maximum 24 MHz Maximum clock or gate input frequency 24 MHz Minimum pulse width minimum amount of time it 50 ns takes a C T to recognize an input pulse Input voltage range 0 to 3 3 V 5 V tolerance Inputs I
73. ut data stream One tachometer input signal The value of the tachometer input signal can be returned in the input stream One phase measure counter You can program the edge that starts the measurement and the edge that stops the measurement Many edge types are supported The data from the measure counter can be returned in the input stream 2 GB embedded NAND flash memory that contains the Linux kernel bootloader and file system this memory can also be used to store user files and data 512 MB SDRAM DDR3 memory 8 kBytes EEPROM Micro SD connector supports micro SD cards which can be used as a boot source for general purpose file and data storage 3 3 V UART I2C and an SPI Serial Peripheral Interface interfaces for embedded connectivity 13 Chapter 1 Serial debug port e External power connectors 4 pin DIN or 3 pin Phoenix header for connecting a 5 VDC power supply 14 Overview Board Layout Overview The DT7837 module consists of an ARM block and a I O block Figure 2 shows the layout of the ARM block the bottom board Figure 3 shows the layout of the I O block the top board 15 Chapter 1 Digital Connector Power LED Tachometer Digital I O External Trigger Counter Timer Connector to the 1 0 Block Serial SPI i Port 1 Port witi y Q1 4 J12 A ico Reset Boot Switch AM3552 Processor Ethernet USB Host Grounding USB Device SD Card 5 V Power Connector Por
74. y is slower than the selected input frequency then the new measure count value is stored as each period measurement completes When an input subsystem sample occurs then the most recently stored measure count is written into the input data stream When the selected start edge is not the same as the selected stop edge the internal 48 MHz counter starts incrementing when it detects the selected start edge and stops incrementing when it detects the next selected stop edge at that point the counter stores and resets the count The stored count is maintained until it is read as part of the input data stream or until a new count is stored The value of the measure count depends on the input subsystem sample frequency described as follows e If the input subsystem sample rate is faster than the selected measurement period then the stored count retains the current value when the count is read by the input subsystem The operation of the Stale flag in this case is described as follows If another input subsystem sample occurs before another measure completes and the Stale flag is used then the Stale flag is set and the stale measure count is written into the input data stream If another input subsystem sample occurs before another measure completes and the Stale flag is not used then the Stale flag is not set and the stale measure count is written into the input data stream Principles of Operation Table 3 e Ifthe input subsyste
75. ysically connect the clock input signal to this input pin Refer to page 27 for the pin descriptions of the Digital connector Refer to page 39 for an example of connecting an event counting application 39 Chapter 2 40 Rate Generation Use rate generation mode to generate a continuous pulse output signal from the counter s output signal You can use this pulse output signal as an external clock to pace other operations such as an analog input or other counter timer operations The pulse output operation is enabled whenever the counter s gate signal is at the specified level While the pulse output operation is enabled the counter outputs a pulse of the specified type and frequency continuously As soon as the operation is disabled rate generation stops You can output pulses using a maximum frequency of 24 MHz if using the internal C T clock or 5 MHz if using the external C T clock Note The integrity of the signal degrades at frequencies greater than 10 MHz Using software you must specify the following parameters for the rate generation operation Active gate type external low level or external high level Refer to page 37 for more information about the supported gate types The general purpose input pin to use for the external gate signal Ensure that you physically connect the gate signal to this input pin Refer to page 27 for the pin descriptions of the Digital connector The C T clock source inter

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