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Campbell SDM-INT8 Instruction Manual

8 channel interval timer
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SDM-INT8
8 Channel Interval Timer
Revision: 4/09
C o p y r i g h t
©
1 9 8 9 - 2 0 0 9
C a m p b e l l
S c i e n t i f i c ,
I n c .

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Summary of Contents for Campbell SDM-INT8

  • Page 1 SDM-INT8 8 Channel Interval Timer Revision: 4/09 C o p y r i g h t © 1 9 8 9 - 2 0 0 9 C a m p b e l l S c i e n t i f i c ,...
  • Page 2 PLEASE READ FIRST About this manual Please note that this manual was originally produced by Campbell Scientific Inc. (CSI) primarily for the US market. Some spellings, weights and measures may reflect this origin. Some useful conversion factors: 1 in (square inch) = 645 mm Area: 1 in.
  • Page 3 WARRANTY AND ASSISTANCE This equipment is warranted by CAMPBELL SCIENTIFIC (CANADA) CORP. (“CSC”) to be free from defects in materials and workmanship under normal use and service for twelve (12) months from date of shipment unless specified otherwise. ***** Batteries are not warranted.

  • Page 4: Table Of Contents

    SDM-INT8 Table of Contents PDF viewers note: These page numbers refer to the printed version of this document. Use the Adobe Acrobat® bookmarks tab for links to specific sections. 1. Overview...............2 2. Specifications ..............3 3. Connections ..............4 4. Power Supply Considerations ........5 5.
  • Page 5 B. Processing Time Limitations ......... B-1 C. INT8 Input Schematic..........C-1 List of Figures 1. SDM-INT8 Front Panel ................1 2. Voltage Input Options, Edges and Thresholds........... 2 3. Wiring Diagram ..................5 4. Example of Multiple Beginnings and Endings ........16 A-1.

  • Page 6: Sdm-Int8 Front Panel

    SDM-INT8 8 Channel Interval Timer FIGURE 1. SDM-INT8 Front Panel...

  • Page 7: Overview

    FIGURE 2. Voltage Input Options, Edges, and Thresholds In CRBasic, the SDMINT8 instruction is used to program and control the SDM-INT8; in Edlog, Instruction 101 is used. These instructions, address, command, and receive data from the INT8 through three ports on the datalogger (see Section 3).

  • Page 8: Specifications

    SDM-INT8 8 Channel Interval Timer 2. Specifications Operating voltage: 9.6 V to 16 V DC Current drain: 13 to 20 mA active, 400 microamp quiescent Environmental: -25 to +50 degrees Celsius 0 to 90% RH (non-condensing) Number of channels: 8 Maximum timing measurement: 16.7 seconds...

  • Page 9: Connections

    The CABLE5CBL-L cable connects the SDM-INT8 to a datalogger. The datalogger-to-SDM-INT8 connections are shown in Figure 3. Please note that the SDM-INT8 connects to the CR9032 CPU module of the CR9000X and the CR9080 PAM module of the CR9000. INT8s are shipped from the factory with a 10K Ohm resistor attached to the terminal strip for the convenience of 21X user.

  • Page 10: Power Supply Considerations

    SDM-INT8 8 Channel Interval Timer CR800, CR850, CR9032 (CR9000X), CR9080 (CR9000), CR10(X), CR23X, CR3000, CR1000 CR5000 SDM-C3 SDM-C2 SDM-C1 10K OHM RESISTOR FIGURE 3. Wiring Diagram 4. Power Supply Considerations The datalogger's power supply is typically used to power the INT8, however, an auxiliary supply may be used as shown in Figure 3.

  • Page 11: Crbasic Programming

    SDM-INT8 8 Channel Interval Timer 5.1 CRBasic Programming 5.1.1 Instruction SDMINT8 The SDMINT8 instruction is used to program and control the SDMINT8 interval timer module. Description of the instruction follows. Syntax SDMINT8 (Dest, SDMAddress, Config8_5, Config4_1, Funct8_5, Funct4_1, OutputOpt, CaptureTrig, Mult, Offset) Dest: Dest is used to specify the array where the results of the instruction are stored.
  • Page 12 SDM-INT8 8 Channel Interval Timer Function8_5: The Function8_5 parameter is a four digit code used to program the timing function of channels 5 through 8. Similar to the Config parameters, digits represent the channels in descending order from left to right (e.g., 8 7 6 5).

  • Page 13: Sdmspeed Instruction

    SDM-INT8 8 Channel Interval Timer as a trigger to start making measurements. The Dest parameter must be dimensioned large enough to receive the captured events. -9999: Initiates a self memory test of the INT8. A numeric code is returned to indicate the results of the test.

  • Page 14: Edlog Programming (Instruction "101")

    SDM-INT8 8 Channel Interval Timer The equation used to calculate the bit rate depends on the datalogger used. The datalogger will round down to the next faster bit rate. Equation for CR800, CR850, and CR1000: bit_rate=INT((k*72)/625)*Resolution Where: k= the value entered in BitPeriod Resolution=8.68 microseconds...

  • Page 15: Programming Details

    SDM-INT8 8 Channel Interval Timer TABLE 2. Instruction 101 Parameter Data Description Type Address (Section 6.1) *Input config; channels 8,7,6,5 *Input config; channels 4,3,2,1 **Function; channels 8,7,6,5 **Function; channels 4,3,2,1 ***Output option Mult Offset Execution time: 2.3 ms + 1.65 ms/value + averaging interval...

  • Page 16: Input Configuration

    SDM-INT8 8 Channel Interval Timer connected to the datalogger must have a unique address. See Appendix A for details on changing the address. 6.2 Input Configuration Each of the 8 input channels can be configured for either high level or low level voltage input, and for rising or a falling edge detect (see Figure 2).
  • Page 17 SDM-INT8 8 Channel Interval Timer 6 - Low resolution frequency (kHz)-- For this function to return low resolution data, it must be the only function used in the instruction. If this is not the only function used in the instruction, it returns high resolution data, the same as Function 2.

  • Page 18: Output Option

    SDM-INT8 8 Channel Interval Timer Channel 1: frequency (2) Channel 3: counts on channel 2 since channel 1 (5) Channel 4: frequency (2) Channel 5: time since previous Channel (3) Channel 2,6,7,8: none (0) Channel 1: RPM may be calculated from crankshaft frequency.

  • Page 19: Input Frequency (Khz) At Which Processing Time Equals Measuring Storing Time

    SDM-INT8 8 Channel Interval Timer TABLE 3. Input Frequency (kHz) at Which Processing Time Equals Measuring/Storing Time 1,2,6,7 0.14 - 0.05F 2 3.4 - 0.81F 2 0.07 - 0.02F2 1.6 - 0.38F2 0.99 0.05 - 0.02F2 0.99 - 0.24F2 0.70 0.76...

  • Page 20: Sampling Interval (Seconds) To Accumulate 8000 Unprocessed Events For Functions 1,2,6,7

    SDM-INT8 8 Channel Interval Timer TABLE 4. Sampling Interval (Seconds) to Accumulate 8000 Unprocessed Events for Functions 1,2,6,7 Input Number of Channels Freq. kHz 5.26 7.97 2.84 1.48 4.21 1.81 1.00 2.67 1.26 5.62 1.87. 3.68 1.38 2.64 1.07 2.00 6.55...

  • Page 21: Option 0: Execution Interval Averaging

    SDM-INT8 8 Channel Interval Timer FIGURE 4. Example of Multiple Beginnings and Endings 6.4.2 Option 0: Execution Interval Averaging When Option 0 is selected, the result from each channel is a value averaged over the interval since the INT8 was previously addressed. Normally this would be the execution interval.

  • Page 22: Option Nnnn Or Xxxx: Specified Averaging Interval

    SDM-INT8 8 Channel Interval Timer Assume the input frequency is 0.5 Hz, and the execution interval of Instruction 101 is 10 Hz. The datalogger input location is updated at about 0.5 Hz if a change occurred, not every time the INT8 is addressed.

  • Page 23: Option 9999--: Test Memory

    SDM-INT8 8 Channel Interval Timer Since the number of values returned may be variable, making it difficult to assign a fixed number of input locations, the Capture All Events Option outputs data directly to the datalogger's Final Storage when Instruction 101 is executed.

  • Page 24: Dest, Input Location, Multiplier, And Offset

    SDM-INT8 8 Channel Interval Timer TABLE 5. Definition of Test Memory Option Output Output Definition positive integer = ROM signature, good RAM negative integer = ROM signature, bad RAM = bad ROM = bad ROM, bad RAM A result of executing Option 9999-- is that the program residing in the INT8 is deleted, and the INT8 goes into the low current drain standby mode.

  • Page 25: Program Examples

    SDM-INT8 8 Channel Interval Timer When using the Capture All Events Option (no averaging), the data are directed to Final Storage of the datalogger rather than Input locations. The first execution of Instruction 101 will program the INT8. Subsequent executions of Instruction 101 with the Output Flag set will output all events to Final Storage.

  • Page 26: Edlog Program Examples

    SDM-INT8 8 Channel Interval Timer ‘Declare Public Variables Public Int8(5) Public PulseCh(2) Dim I ‘Define Data Tables DataTable (Dat5min,1,-1) DataInterval (0,5,Min,10) average (5,Int8(),FP2,False) EndTable ‘Main Program BeginProg Scan (5,Sec,0,0) ‘measure 03101 on P1 & P2 WS_ms: PulseCount (PulseCh(1),1,1,1,1.75,.2) PulseCount (PulseCh(2),1,2,1,1.75,.2) ‘measure 03101 on SDMINT8 channel 1 through channel 5...
  • Page 27 SDM-INT8 8 Channel Interval Timer Parameter 6 (Capture All Events) is programmed for 20--to capture edge times on channels 1-5 until 20 edges are received on channel 1. Flag 2 is used in the example to indicate the start of the cranking. In actual test program, this flag could be set in response to an ignition switch measurement indicating the start of the test.

  • Page 28: Wind Speed Measurements - Execution Interval Averaging

    SDM-INT8 8 Channel Interval Timer 3: Beginning of Loop (P87) loop to make a 10 sec. 1: 1 Delay delay 2: 20 Loop Count 4: End (P95) end of loop 5: Do (P86) set the output 1: 10 Set high Flag 0 (output)

  • Page 29: Brake Pressure And Wheel Speed Test - Capture All Events

    SDM-INT8 8 Channel Interval Timer *Table 1 Programs 01: 1 Sec. Execution interval 1: SDM-INT8 (P101) measure wind speed 1: 00 Address Option 2: 0022 Chan8765=HLrise/HLrise/LLrise/LLrise/ 3: 2222 Chan4321=LLrise/LLrise/LLrise/LLrise 4: 0022 Chan8765=none/none/kHz/kHz/ 5: 2222 Chan4321=kHz/kHz/kHz/kHz/ 6: 0 Execution interval averaging (1 second)
  • Page 30 SDM-INT8 8 Channel Interval Timer *Table 1 Programs 01: .125 Sec. Execution interval 1: If Flag/Port (P91) 1: 21 Do if flag 1 is low 2: 0 Go to end of Program Table 2: Do (P86) 1: 10 Set high Flag 0 (output)
  • Page 31 SDM-INT8 8 Channel Interval Timer 11: Set Active Storage Area (P80) 1: 1 Final Storage Area 1 2: 1 Array ID or location 12: Sample (P70) 1: 200 Reps 2: 1 13: Do (P86) 1: 10 Set high Flag 0 (output)

  • Page 32: A. Address Jumper

    Appendix A. Address Jumper The address is factory set at address 00. Figure A1 (also shown inside the INT8 cover) shows the 16 possible positions and their corresponding address. Use the addresses shown in Figure A1 in Instruction 101. The address block requires soldering to change the address. If two or more INT8s are to be used on the same datalogger, one can remain at address 00, while the others must be changed.
  • Page 33 This is a blank page.

  • Page 34: B. Processing Time Limitations

    Appendix B. Processing Time Limitations With the exception of the Capture All Events Option or when all channels are programmed for low resolution frequency (Function 6), the INT8 is performing two tasks simultaneously: (1) measuring and storing, and (2) doing the processing necessary for the final calculations of averages.
  • Page 35 Appendix B. Processing Time Limitations If the T t for Output Option XXXX is greater than the specified interval, the extra time will be added to the execution time of Instruction 101. Example 1 Given: Output Option = XXXX Specified interval = S = 500 ms Function = frequency (Function 2) Number of channels measured = N = 6 Average input frequency = F = 1kHz...
  • Page 36 Appendix B. Processing Time Limitations Example 3 Given: N = number of channels measured F = Frequency of input signal, kHz Function = frequency (Function 2) Output Option = XXXX with specified sampling interval, S Find: Sampling interval, S, such that the number of unprocessed events is d 8000 Solution: The interval required to process 8000 events after the sampling interval is T t -S, therefore;...
  • Page 37 Appendix B. Processing Time Limitations This is a blank page.

  • Page 38: C. Int8 Input Schematic

    Appendix C. INT8 Input Schematic...
  • Page 39 This is a blank page.
  • Page 41 Campbell Scientific Companies Campbell Scientific, Inc. (CSI) 815 West 1800 North Logan, Utah 84321 UNITED STATES www.campbellsci.com • info@campbellsci.com Campbell Scientific Africa Pty. Ltd. (CSAf) PO Box 2450 Somerset West 7129 SOUTH AFRICA www.csafrica.co.za • cleroux@csafrica.co.za Campbell Scientific Australia Pty. Ltd. (CSA)

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