CompuScope SDK Manua.. - Egmont Instruments

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DIGITAL_INPUT.EXEThe sample program DIGITAL_INPUT.EXE is provided with CompuScope SDK for C/C++ for Windows.The sample program is provided for use with digital input CompuScopes like the CS3200. Conceptually, adigital input CompuScope is just like analog input CompuScope with its analog signal conditioning frontend and A/D converter chips replaced with a digital input buffer. Because of the similarity in the operationof the analog and digital CompuScopes, Gage uses exactly the same set of subroutines (the API) to accessboth types of CompuScopes. Gage has modified the operation of some API subroutines for digital inputCompuScopes so that they fit the functionality of these boards.Three important differences exist that must be considered when programming a digital input CompuScope1. CompuScope Mode. – For an analog CompuScope the operating mode, SINGLE or DUAL, specifiesthe number of channels on which to acquire analog signals. For digital input CompuScopes, however, themode parameter is used to specify the digital input width. The CompuScope 3200, for instance, can beconfigured for 8, 16 or 32 bit input width. In this way, memory usage is optimized. For example, aCompuScope 3200 with 2 Mega Bytes of on-board memory can capture 2 Mega Samples in 8-bit mode, 1Mega Samples in 16-bit mode and one-half Mega Samples in 32-bit mode. In order to control the mode,the programmer must set the board.opmode to GAGE_SINGLE_CHAN for 8-bit mode,GAGE_DUAL_CHAN for 16-bit mode and GAGE_QUAD_CHAN for 32-bit mode.2. Logic Input Levels. – One may specify the logic input levels for digital input CompuScopes. Forinstance, for the single-ended CompuScope 3200, the logic level may be selected to be either CMOS (witha logic threshold of about 2.5 Volts) or TTL (with a logic threshold of about 1.4 Volts). The selection ofeither logic level is done through the analog input range control for channel A, which has no meaning on adigital input CompuScope. For selection of the CMOS logic level, the programmer must select the ±5Volts input range and for TTL, the ±1 input range. So the programmer should set board.range_a toGAGE_PM_5_V for CMOS logic and should set board.range_a to GAGE_PM_1_V for TTL logic.3. External Sampling Clock Inversion. – Most digital input applications require the use of an externalclock. In digital electronics, the digital data are generally stable on either one clock edge or the other(rising or falling). The user’s device under test may have differential signal propagation delays, whichmeans that the clock and digital data may take different times to arrive at the digital CompuScope. Theuser, therefore, may not know upon which clock edge the data are stable. Consequently, the user must becapable of selecting on which clock edge the digital signals are sampled. The sampling clock edge may beselected using the use_invert_clock variable. If the use_invert_clock variable is set to 0 then the digitalCompuScope will sample on the rising edge of the input external clock. If the use_invert_clock variable isset to 1 then the digital CompuScope will sample on the falling edge of the input external clock.The DIGITAL_INPUT sample program captures a digital signal in single-(8 bit), dual-(16 bit), or quad-(32bit) mode from a digital input CompuScope. All captured data are written to separate ASCII data files.Data are stored as unsigned integers in decimal format with ranges 0-255, 0-32767 and 0-4,294,967,295 for8, 16 and 32 bit modes respectively.In order to view the resulting files, you will have to run Microsoft Excel or another program, whichallows you to import ASCII data. You can also use any text editor. In Microsoft Excel, data files can beread by opening them from the File menu. Excel’s Import Wizard will guide you through importing thedata. Select “Delimited” for the type of data, and “Tab” as the delimiter for the data. You can then plot thedata.Page 50CompuScope SDK Manual
Description of the Routines used by the sample programFollowing are the routines used by the sample program DIGITAL_INPUT. A brief description for all theGage API routines used by each of the following routines is also given. For detailed description of all theGage API routines, please see the CompuScope API Reference Manual.int CALLBACK WinMain . . . . . . . .This is the main routine in DIGITAL_INPUT.C. In this routine, we first initialize the CompuScope driverand hardware and verify the board structure for the CompuScope boards.We make setting adjustments using the board_settings routine and then prepare the CompuScope boardfor data capture with the SetBoard routine.We then start the acquisition. Two driver routines: gage_triggered and gage_busy are used to monitor theprogress of the trigger event and the completion of the current data acquisition, respectively.Once the acquisition is complete, we determine the relevant addresses by callinggage_calculate_addresses. The data record is transferred to PC RAM using PCI bus-mastering bygage_transfer_buffer_3.For 8 bit mode, gage_transfer_buffer_3 routine returns 8 bit samples in an int8 space.For 16 bit mode, gage_transfer_buffer_3 routine returns 16 bit samples in an int16 space.For 32 bit mode, gage_transfer_buffer_3 routine returns 32 bit samples in an int32 spaceAfter the data are read, we save the data from the digital input to an ASCII data file called D_INPUT.DATin the current working directory.Gage API routines used by gage_transfer_buffer_3:gage_get_driver_info:gage_start_capture:gage_triggered:gage_force_capture:gage_busy:gage_abort_capture:gage_transfer_buffer_3:Fills a structure or record with the relevant information from thedriver variables about the current CompuScope board settings.Prepares the CompuScope hardware for data acquisition.Determines if the CompuScope hardware has encountered a triggerevent.Forces the capture of data by the CompuScope board(s).Determines if the CompuScope board is busy capturing the data.Used to regain control of the CompuScope board(s).Copies the number of sample points requested from theCompuScope board’s memory space from the specified channel tothe supplied buffer using bus-mastering. This routine returns anoffset to the beginning of the d-word aligned buffer that the driveruses.CompuScope SDK Manual Page 51
Page 1 and 2:
Volume I:CompuScope C/C++Software D
Page 3 and 4:
Gage Applied Technologies, Inc. Sof
Page 5:
Global Table of ContentsVolume I Co
Page 8 and 9: Chapter 5: Sample ProgramsWindows S
Page 11 and 12: PrefaceImportant Notes:• The Comp
Page 13: Chapter 2: BasicCompuScopeOperation
Page 16 and 17: CompuScope A/D cards generally oper
Page 18 and 19: Multiple CompuScope SystemsThe Comp
Page 20 and 21: Plug-n-Play is an inherent part of
Page 22 and 23: On-Board MemoryOrganization of theC
Page 24 and 25: memory counter overflow rolls over
Page 26 and 27: If during the data acquisition the
Page 28 and 29: On-board Memory: A Programmer’s V
Page 30 and 31: CompuScope RepetitiveCapture Perfor
Page 32 and 33: depth portion of the single channel
Page 34 and 35: Page 26CompuScope SDK Manual
Page 36 and 37: Sample Programs Folder Structure us
Page 38 and 39: • Gage_drv.hGage_drv.h contains g
Page 41 and 42: Writing a C Application forCompuSco
Page 43 and 44: The last routine, gage_trigger_cont
Page 45: Chapter 5:Sample Programs
Page 48 and 49: Program NameA2D_PAGED_TRANSFER.EXED
Page 50 and 51: Flow Chart describing the sample pr
Page 52 and 53: gage_trigger_control_2:gage_set_ext
Page 54 and 55: GAG2A2D_MUL_BM.EXEThe sample progra
Page 56 and 57: Gage API routines used:gage_get_dri
Page 61: Chapter 6:Appendices
Page 64 and 65: uInt32 sample_rate;void far *memptr
Page 66 and 67: trigger_level level at which trigge
Page 68 and 69: trigger_sensitivitytrigger_bandwidt
Page 70 and 71: Settings for boarddef structure fie
Page 72 and 73: 10 KHz SRTI_10_KHZ5 KHz SRTI_5_KHZ2
Page 74 and 75: • couple_eThe parameter couple_e
Page 76 and 77: Example:Below is illustrated a typi
Page 79 and 80: Appendix C: CompilingCompuScope SDK
Page 81: Creating a new LabWindows CVI proje
Page 84 and 85: Arbitrary Waveform GenerationOne co
Page 86 and 87: Technical SupportGage Applied Techn
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