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Diamond Systems Athena III Скачать руководство пользователя страница 61

Athena III User Manual Rev A.03

www.diamondsystems.com

Page

61

13. ANALOG-TO-DIGITAL INPUT RANGES AND RESOLUTION

13.1

Overview

Athena III uses a 16-bit A/D converter. The full range of numerical values for a 16-bit number is 0 - 65535.
However, the A/D converter uses two’s complement notation, so the A/D value is interpreted as a signed integer,
ranging from

–32768 to +32767.

The smallest change in input voltage that can be detected is 1/(216), or 1/65536, of the full-scale input range.
This smallest change results in an increase or decrease of 1 in the A/D code, and is referred to as 1 LSB (1 Least
Significant Bit).

The analog inputs on Athena III have three configuration options.

Single-ended or differential mode

Unipolar or bipolar mode

Input range (gain)

The single-ended/differential and unipolar/bipolar modes are configured using jumper block J26, and apply to all
inputs. The input range selection is done in software.

13.1.1

Input Range Selection

You  can  select  a  gain  setting  for  the  inputs,  which  causes  them  to  be  amplified  before  they  reach  the  A/D
converter.    The  gain  setting  is  controlled  in  software,  which  allows  it  to  be  changed  on  a  channel-by-channel
basis.  In general, you should select the highest gain (smallest input range) that allows the A/D converter to read
the full range of voltages over which the input signals will vary.  However, a gain that is too high causes the A/D
converter to clip at either the high end or low end, and you will not be able to read the full range of voltages on
your input signals.

13.1.2

Input Range Table

The table below indicates the analog input range for each possible configuration.  The polarity is set using jumper
block J26, and the gain is set with the G1 and G0 bits in the register at Base+3.  The Gain value in the table is
provided  for  clarity.    Note  that  the  single-ended  vs.  differential  setting  has  no  impact  on  the  input  range  or  the
resolution.

Polarity

G1

G0

Input Range

Resolution 1LSB

Bipolar

0

0

±10V

305µV

Bipolar

0

1

±5V

153µV

Bipolar

1

0

±2.5V

76µV

Bipolar

1

1

±1.25V

38µV

Unipolar

0

0

Invalid

Invalid

Unipolar

0

1

0 - 10V

153µV

Unipolar

1

0

0 - 5V

76µV

Unipolar

1

1

0 - 2.5V

38µV

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Содержание Athena III

Страница 1: ...sition Rev A 03 May 2014 Revision Date Comment A 03 5 16 2014 Minor version Copyright 2014 FOR TECHNICAL SUPPORT Diamond Systems Corporation PLEASE CONTACT 555 Ellis Street Mountain View CA 94043 USA...

Страница 2: ...ces 11 3 2 6 Connecting Power 11 3 2 7 Display 11 3 3 BOOTING THE SYSTEM 12 3 3 1 BIOS Setup 12 3 3 2 Operating System Drivers 12 4 FUNCTIONAL OVERVIEW 13 4 1 FUNCTIONAL BLOCK DIAGRAM 13 4 2 FUNCTIONA...

Страница 3: ...37 8 4 BACKUP BATTERY 37 8 5 SYSTEM RESET 37 9 BIOS 38 9 1 BIOS SETTINGS 38 9 1 1 Serial Ports 38 9 1 2 Parallel Port 38 9 1 3 LCD Video Settings 38 9 1 4 Miscellaneous Settings 38 9 2 BIOS CONSOLE RE...

Страница 4: ...69 16 4 1 D A Conversion Formulas for Unipolar Output Ranges 69 16 4 2 D A Conversion Formulas for Bipolar Output Ranges 70 17 GENERATING AN ANALOG OUTPUT 71 17 1 COMPUTE THE D A CODE FOR THE DESIRED...

Страница 5: ...edge to avoid possible shorting from this type of damage However these design rules are not sufficient to prevent damage in all situations A third cause of failure is when a metal screwdriver tip slip...

Страница 6: ...acceptable range of voltages connected to digital I O signals is 0 5V and they can withstand about 0 5V beyond that 0 5 to 5 5V before being damaged However logic signals at 12V and even 24V are comm...

Страница 7: ...ly The Athena III SBC uses the ISA bus internally to connect serial ports 1 through 4 and the data acquisition circuit to the processor The ISA bus is brought out to an expansion connector to mate wit...

Страница 8: ...counter timer for A D sample rate control event counting and programmable interrupts Auto calibration with Universal Driver software support for all data acquisition functions 2 3 Expansion Options US...

Страница 9: ...receive the product as part of Diamond s Athena III Development Kit which provides everything needed to ensure rapid application development This section of the Athena III User Manual covers basic har...

Страница 10: ...thena III Cable Kit number C ATHE KIT provides convenient access to most of Athena III s I O features The kit s cable assemblies are shown in the photo below and identified in the table that follows I...

Страница 11: ...board and mouse connectors into the appropriate connectors on the Main I O cable in the Athena III Cable Kit cable number C PRZ 01 Connect the end of the cable into connector J18 on Athena III 3 2 4 U...

Страница 12: ...s other hardware and software parameters Options configurable via Setup typically include Number and type of mass storage devices Boot device priority Video display type and resolution IDA SATA serial...

Страница 13: ...II s core embedded computer circuit features the ultra low power Intel Atom Queensbay extended temperature platform consisting of an Atom processor Tunnel Creek with I O Hub Topcliff The rest of the c...

Страница 14: ...th capacity up to 8GB 4 2 6 Serial Ports Athena III provides four serial ports with varying protocols and signal availability The SCH3114 provides two of the serial ports The other two serial ports ar...

Страница 15: ...nd enable use of an external battery instead External battery voltage requirement is 3 3V 10 4 2 11 Watchdog Timer A programmable watchdog timer WDT is included to provide an automatic reset in case o...

Страница 16: ...PTION The figure below shows the Athena III SBC layout with connector and jumper block locations labeled On the following page is a figure showing the key dimensions on the Athena III PCB in millimete...

Страница 17: ...Athena III User Manual Rev A 03 www diamondsystems com Page 17...

Страница 18: ...A B J11 PC 104 ISA bus C D J14 USB flashdisk J15 USB 0 1 J16 USB 2 3 J17 USB Client Port Utility J18 Main I O serial ports PS 2 keyboard mouse parallel port utility J21 Input Power J23 Data Acquisitio...

Страница 19: ...he LEDs found on the Athena III SBC LED Number Description Color LED46 DAQ FPGA loaded successfully Blue LED1 SATA activity Green LED2 Ethernet activity Green LED3 Ethernet Link 100Mbps Green LED4 Eth...

Страница 20: ...external battery for maintaining the Real Time Clock and the CMOS settings BIOS settings for various system configurations The battery voltage for this input should be 3 3 6VDC The current draw averag...

Страница 21: ...J5 Connector J5 is a 2x4 pin header for connecting a VGA monitor Green 1 2 Red Blue 3 4 Ground HSYNCE 5 6 DDC data VSYNC 7 8 DDC clock Signal Definition Ground Ground return Red RED signal positive 0...

Страница 22: ...21 22 Scan Direction LVDS data 1 23 24 LVDS Map Ground 25 26 Ground VDD LCD display 27 28 VDD LCD display VDD LCD display 29 30 VDD LCD display Signal Definition LVDS Data 0 2 Primary Data Channel bit...

Страница 23: ...embedded microcontroller or by pin 6 on this connector A jumper selects the source of the brightness signal to this pin Connector on board Molex 53047 0610 or equivalent Mating Cable Connector Molex...

Страница 24: ...15 SD1 A8 B8 ENDXFR LA18 C7 D7 IRQ14 SD0 A9 B9 12V LA17 C8 D8 DACK0 IOCHRDY A10 B10 Key MEMR C9 D9 DRQ0 AEN A11 B11 SMEMW MEMW C10 D10 DACK5 SA19 A12 B12 SMEMR SD8 C11 D11 DRQ5 SA18 A13 B13 IOW SD9 C1...

Страница 25: ...J15 J16 Connectors J15 USB 0 1 and J16 USB 2 3 provide four USB 2 0 ports The connectors have identical pinouts as described below J15 J16 USB Connectors Key pin cut 1 2 Shield GND 3 4 GND USB1 3 D 5...

Страница 26: ...Power switch Reset switch Power and HDD LEDs J18 Main I O Connector COM1 COM4 signals depend on the selected protocol The pinout shown on the next page is for RS 232 For RS 422 or RS 485 the following...

Страница 27: ...CTS2 15 15 PD6 DTR2 16 16 GND RI2 17 17 PD7 GND 18 18 GND COM3 DCD3 19 19 ACK DSR3 20 20 GND RXD3 21 21 BUSY RTS3 22 22 GND TXD3 23 23 PE CTS3 24 24 GND DTR3 25 25 SLCT RI3 26 26 KB Clk KYBD GND 27 2...

Страница 28: ...nects to pin 1 of the PS 2 connector KB MS V Power pin connects to pin 4 of the PS 2 connector Utilities A 5V Out Switched power pin that is turned on and off with the ATX power switch or with the 5V...

Страница 29: ...er In particular many disk drives need extra current during startup If your system fails to boot properly or if disk accesses do not work properly the first thing to check is the power supply voltage...

Страница 30: ...7 DIO B0 9 10 DIO B1 DIO B2 11 12 DIO B3 DIO B4 13 14 DIO B5 DIO B6 15 16 DIO B7 DIO C0 17 18 DIO C1 DIO C2 19 20 DIO C3 DIO C4 GATE0 21 22 DIO C5 GATE1 DIO C6 CLK1 23 24 DIO C7 OUT0 EXTTRIG 25 26 TOU...

Страница 31: ...ly Do not connect to external supply DGND Digital ground 0V reference used for digital circuitry only AGND Analog ground used for analog circuitry only Vout pin is for analog outputs Vin pin is for an...

Страница 32: ...k with Default Settings Jumper Location Function Pins 1 2 Pins 2 3 Pins 5 6 Pins 6 7 LCD VDD set to 5V default LCD VDD set to 3 3V Backlight inverter VDD set to 5V default Backlight inverter VDD set t...

Страница 33: ...fault A D X X default X Note IRQ4 can only be used for the data acquisition circuit if it is not already used for COM3 It is possible to set up all three circuits to share either IRQ4 or IRQ5 However...

Страница 34: ...input uses two wires input and ground The measured input voltage is the difference between these two wires A differential input uses three wires input input and ground The measured input voltage is th...

Страница 35: ...bipolar both positive and negative input voltages For unipolar inputs install a jumper as shown below For bipolar inputs omit the jumper The default configuration is bipolar mode jumper out A D Unipol...

Страница 36: ...PC 104 Plus cards that are in the system These settings may also vary depending on what other devices are present in the system For example adding a PC 104 Plus card may change the on board Ethernet...

Страница 37: ...bottom for Continue C R after POST select Off default to turn off after POST or select On to remain on always 4 Exit the BIOS and save your settings 8 3 Flash Memory Athena III contains a 2048KB 16 b...

Страница 38: ...Type This setting defaults to 7 Do not alter this setting unless specifically instructed to do so This setting affects the LCD display modes supported mode 7 is the only setting currently supported No...

Страница 39: ...spend to RAM Memory Shadow These parameters should only be modified by advanced users These settings can adversely affect system performance and reliability 9 2 BIOS Console Redirection Settings For a...

Страница 40: ...not required Additional software support includes a packet driver with software to allow a full TCP IP implementation 10 2 Serial Ports Athena III contains four serial ports Each port is capable of tr...

Страница 41: ...sequence in the BIOS so the system boots from CD ROM first 2 Insert the Windows installation CD into the CD ROM and restart the computer 3 Follow the manufacturer s instructions for installing Window...

Страница 42: ...a 16 bit counter timer for user applications High speed A D sampling is supported with interrupts and a FIFO The FIFO is used to store a user selected number of samples and the interrupt occurs when t...

Страница 43: ...ided the board is in enhanced mode Page 0 Base Write Function Read Function 0 Command A D LSB 1 Enhanced mode control A D MSB 2 A D channel A D channel 3 A D gain page select scan settings A D gain an...

Страница 44: ...B4 B3 B2 B1 B0 10 C7 C6 C5 C4 C3 C2 C1 C0 11 DIOCTR DASIM DIRA DIRCH DIRB DIRCL Page 0 Read Register Summary Base 7 6 5 4 3 2 1 0 0 AD7 AD6 AD5 AD4 AD3 AD2 AD1 AD0 1 AD15 AD14 AD13 AD12 AD11 AD10 AD9...

Страница 45: ...4 D3 D2 D1 D0 13 A7 A6 A5 A4 A3 A2 A1 A0 14 TDBUSY EEBUSY CALMUX 15 0xA1 Page 2 Write Register Summary Base 7 6 5 4 3 2 1 0 12 EXFIFO 13 DACPOLE N DACPOL ADPOL ADPOLEN ADSD ADSDEN 14 SCANINT 15 DAQ_LE...

Страница 46: ...ggered by writing to this bit Instead the A D will be triggered by a signal selected by ADCLK in base 4 bit 5 RSTBRD Reset the entire board excluding the D A Writing a 1 to this bit causes all registe...

Страница 47: ...e combined into a single formula for efficiency Base 1 Write Enhanced Features Access Register Bit No 7 6 5 4 3 2 1 0 Name PG1 PG0 Reset 0 0 0 0 0 0 0 0 This register has dual function When 0xA5 and 0...

Страница 48: ...og input circuit is settling During this time an A D conversion should not be performed because the data will be inaccurate After writing a new gain setting Base 3 the ADWAIT bit is also set and the p...

Страница 49: ...l is HIGH The STS bit stays high during the A D conversion ADG1 0 Analog input gain The gain is the ratio of the voltage seen by the A D converter and the voltage applied to the input pin The gain set...

Страница 50: ...the gain register Base 3 is changed It stays high for 9 microseconds The program should monitor this bit after writing to either register and wait for it to become 0 prior to starting an A D conversi...

Страница 51: ...1 0 internal clock output from counter timer 0 1 external clock input EXTTRIG DMAEN Enable DMA operation 1 enable 0 disable TINTE Enable timer interrupts 1 enable 0 disable DINTE Enable digital I O i...

Страница 52: ...ically to 1024 The interrupt routine is responsible for reading the correct number of samples out of the FIFO The interrupt rate is equal to the total sample rate divided by the FIFO threshold General...

Страница 53: ...Register Description for Page 2 Base 12 Current FIFO depth MSB This value indicates the upper 4 bits of the number of A D values currently stored in the FIFO OVF FIFO Overflow bit This bit indicates...

Страница 54: ...pt status 1 interrupt pending 0 interrupt not pending AINT Analog input interrupt status 1 interrupt pending 0 interrupt not pending ADCH3 0 Current A D channel This is the channel that will be sample...

Страница 55: ...A 4 PC7 Out 0 DIO NOTE If DIOCTR 1 then the pin direction is controlled by DIRCH This bit resets to 1 DIRA Port A direction 0 output 1 input DIRB Port B direction 0 output 1 input DIRCH Port C bits 7...

Страница 56: ...e byte for counter 0 When writing to this register an internal load register is loaded Upon issuing a Load command through Base 15 the selected counter s associated register will be loaded with this v...

Страница 57: ...d Base 13 Any data in Base 14 will be from the previous Counter 0 access GTDIS Disable external gating for the selected counter GTEN Enable external gating for the selected counter If enabled the asso...

Страница 58: ...2 1 0 Name EE_EN EE_RW RUNCAL CALMUX TDACWR X X X This register is used to initiate various commands related to autocalibration EE_EN EEPROM Enable Writing a 1 to this bit will initiate a transfer to...

Страница 59: ...s register each time after any change in the states of registers bits PG1 and PG0 base 1 bits 1 0 in order to get access to the EEPROM This helps prevent accidental corruption of the EEPROM contents O...

Страница 60: ...g 0 unipolar mode 1 bipolar mode Unipolar output setting 0 bipolar mode 1 unipolar mode ADPOLEN Enable ADPOL When this bit is set the ADPOL setting is output to the DAC circuit ADSD Single ended diffe...

Страница 61: ...ain setting for the inputs which causes them to be amplified before they reach the A D converter The gain setting is controlled in software which allows it to be changed on a channel by channel basis...

Страница 62: ...0 to base 2 The first conversion is on channel 0 the second will be on channel 1 and the third will be on channel 2 The channel counter wraps around to the beginning so the fourth conversion will be o...

Страница 63: ...eted return 1 conversion did not complete 14 7 Read the Data from the Board Once the conversion is complete you can read the data back from the A D converter The data is a 16 bit value and is read bac...

Страница 64: ...ep is not included here Only conversion to input voltage is described However you can combine both transformations into a single formula if desired To convert the A D value to the corresponding input...

Страница 65: ...Input voltage 17761 32768 65536 5V 3 855V For a unipolar input range 1 LSB 1 65536 Full scale voltage The following table illustrates the relationship between A D code and input voltage for a unipolar...

Страница 66: ...to an integral number of scans For example if the scan size is 8 channels the FIFO threshold should be set to 8 16 24 32 40 or 48 but not less than 8 This way the interrupt will occur at the end of t...

Страница 67: ...ccurs The user program monitors STS Base 3 bit 7 and reads A D data when STS goes low 1 0 Single A D conversions are triggered by the source selected with ADCLK Base 4 bit 4 STS stays high during the...

Страница 68: ...ena III computer hardware to an analog signal terminating at an external source 16 2 Resolution The resolution is the smallest possible change in output voltage For a 12 bit DAC the resolution is 1 2...

Страница 69: ...nipolar mode 0 10V and Full scale range 10V 0V 10V if Desired output voltage 2 000V D A code 2 000V 10V 4096 819 2 819 Note the output code is always an integer For the unipolar output range 0 10V 1 L...

Страница 70: ...scale range 10V 10V 20V if Desired output voltage 2 000V D A code 2V 10V 2048 2048 2457 6 2458 For the bipolar output range 10V 1 LSB 1 4096 20V or 4 88mV The following table illustrates the relation...

Страница 71: ...mpute the LSB and MSB values LSB D A Code 255 keep only the low 8 bits MSB int D A code 256 strip off low 8 bits keep 4 high bits Example For Output code 1776 Compute LSB 1776 255 240 0xF0 and MSB int...

Страница 72: ...ith 16 bit accuracy exhibit gain and offset errors that vary depending on the gain setting The settings that work best for one range may not be sufficient to calibrate another If a circuit is calibrat...

Страница 73: ...located at pins 1 through 24 on the I O header J14 The lines are 3 3V and 5V logic compatible Each output is capable of supplying 8mA in logic 1 state and 12mA in logic 0 state DIRA DIRB DIRCH and DIR...

Страница 74: ...cept that it is a 16 bit counter Counter 1 also has an input a gate and an output These signals may be user provided on the I O header when DIOCTR is 0 or the input may come from the on board clock ge...

Страница 75: ...e outp base 13 high outp base 14 high 15 Load the counter Counter 0 Counter 1 outp base 15 0x02 outp base 15 0x82 16 Enable the gate if desired The gating may be enabled or disabled at any time When g...

Страница 76: ...eared after stopping disabling and reading the counter If you clear a counter while it is enabled it continues to count incoming pulses so the counter value may not remain at zero 21 Stop disable the...

Страница 77: ...1GB to 8GB of solid state non volatile memory that operates like an USB drive without requiring additional driver software support Model Capacity FDU 1G XT 1GB FDU 2G XT 2GB FDU 4G XT 4GB FDU 8G XT 8G...

Страница 78: ...option to view or modify the BIOS settings for the desired configuration area The screens displayed for each area are described below The following keyboard controls are available on any page for nav...

Страница 79: ...Version 4 6 3 7 Project Version 0DATH 0 12 Build Date 09 07 2012 19 18 24 Product Name Athena III Motherboard Manufacturer Diamond Systems MRC Version 01 00 Total Memory 1024 MB DDR2 Platform Informat...

Страница 80: ...Configuration South Bridge Chipset Configuration IOH Configuration Boot Boot Configuration Quiet Boot Disabled Fast Boot Disabled Setup Prompt Timeout 1 Bootup NumLock State On CSM16 Module Version 0...

Страница 81: ...Save Exit Boot to Windows CE Save Changes and Exit Discard Changes and Exit Save Changes and Reset Discard Changes and Reset Save Options Save Changes Discard Changes Restore Defaults Save as User Def...

Страница 82: ...age interfaces 1 SATA pin header USB flashdisk solid state USB module supports up to 8GB and mounts to SBC Keyboard mouse PS 2 Audio AC 97 Line in Line Out Mic 23 2 Data Acquisition Circuitry Analog i...

Страница 83: ...voltage Logic 0 0 0V min 0 33V max Logic 1 2 4V min 5 0V max Output current Logic 0 12mA max per line Logic 1 4mA max per line A D Pacer clock 24 bit down counter source 10MHz 1MHz or external signal...

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