Stanford Research Systems SR850 User Manual
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Stanford Research Systems SR850 User Manual

Dsp lock-in amplifier
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MODEL SR850
DSP Lock-In Amplifier
Stanford Research Systems
1290-D Reamwood Avenue
Sunnyvale, California 94089
Phone: (408) 744-9040 • Fax: (408) 744-9049
email: info@thinkSRS.com • www.thinkSRS.com
Copyright © 1992 by SRS, Inc.
All Rights Reserved.
Revision 2.0 (01/2009)

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  • Page 1 MODEL SR850 DSP Lock-In Amplifier Stanford Research Systems 1290-D Reamwood Avenue Sunnyvale, California 94089 Phone: (408) 744-9040 • Fax: (408) 744-9049 email: info@thinkSRS.com • www.thinkSRS.com Copyright © 1992 by SRS, Inc. All Rights Reserved. Revision 2.0 (01/2009)

  • Page 3: Table Of Contents

    Using the Disk Drive Aux Outputs and Inputs Trace Math SR850 BASICS What is a Lock-in Amplifier? What Does a Lock-in Measure? The SR850 Functional Diagram Reference Channel Phase Sensitive Detectors Time Constants and DC Gain DC Outputs and Scaling Dynamic Reserve...
  • Page 4 Table of Contents Interface Ready and Status GET (Group Execute Trigger) DETAILED COMMAND LIST Reference and Phase Input and Filter Gain and Time Constant Output and Offset Trace and Scan Display and Scale Cursor Mark Aux Input and Output Math Store and Recall Setup Print and Plot...

  • Page 5: Safety And Preparation For Use

    PMT can charge to several hundred volts in a relatively short time. If this cable is connected to the inputs of the SR850 the stored charge may damage the front-end op amps. To avoid this problem, always discharge the cable and connect the PMT output to the SR850 input before turning the PMT on.

  • Page 7: Specifications

    Output Impedance Amplitude Amplitude Accuracy Amplitude Stability Outputs SR850 DSP LOCK-IN AMPLIFIER Single-ended (A) or differential (A-B). or 10 Volts/Amp. 2 nV to 1 V in a 1-2-5-10 sequence (expand off). Voltage: 10 M +25 pF, AC or DC coupled.

  • Page 8: Inputs And Outputs

    SR850 DSP Lock-In Amplifier INPUTS AND OUTPUTS Channel 1 Output Channel 2 Output X and Y Outputs Aux. Outputs Aux. Inputs Trigger Input Monitor Output DISPLAYS Screen Format Displayed Quantities Display Types Chart Data Buffer ANALYSIS FUNCTIONS Smoothing Curve Fits...

  • Page 9: Command List

    Set (Query) the Monitor Display to settings (0) or Input/Output (1). DTYP (?) i {, j} 6-11 Set (Query) theFull (i=0), Top (i=1) or Bottom (i=2) Display Type to Polar (j=0), Blank (j=1), Bar (j=2) or Chart (j=3). SR850 DSP Lock-In Amplifier Integers Frequency (real) Real Numbers String...
  • Page 10 SR850 DSP Lock-In Amplifier DTRC (?) i {, j} 6-11 Set (Query) theFull (i=0), Top (i=1) or Bottom (i=2) Display Trace to trace j (1,2,3,4). DSCL (?) {x} 6-11 Set (Query) theFull (i=0), Top (i=1) or Bottom (i=2) Display Range to x.
  • Page 11 Set (Query) Fast Data Transfer Mode On (1 or 2) or Off (0).On will transfer binary X and Y eve- ry sample during a scan over the GPIB interface. STRD 6-25 Start a scan after 0.5sec delay. Use with Fast Data Transfer Mode. SR850 DSP Lock-In Amplifier...

  • Page 12: Status Byte Definitions

    *RST 6-26 Reset the unit to its default configurations. *IDN? 6-26 Read the SR850 device identification string. LOCL(?) {i} 6-26 Set (Query) the Local/Remote state to LOCAL (0), REMOTE (1), or LOCAL LOCKOUT (2). OVRM (?) {i} 6-26 Set (Query) the GPIB Overide Remote state to Off (0) or On (1).

  • Page 13: Your First Measurements

    The sample measurements described in this section are designed to acquaint the first time user with the SR850 DSP Lock-In Amplifier. Do not be concerned that your measurements do not exactly agree with these exercises. The focus of these measurement exercises is to learn how to use the instrument.
  • Page 14 Getting Started...

  • Page 15: The Basic Lock-In

    THE BASIC LOCK-IN This measurement is designed to use the internal oscillator to explore some of the basic lock-in functions. You will need BNC cables. Specifically, you will measure the amplitude of the Sine Out at various frequencies, sensitivities, time con- stants and phase shifts.
  • Page 16 The Basic Lock-in 5. Press the <Rotate 90 deg> softkey. Press the <deg.> softkey. Use the knob to adjust the phase shift until Y is zero and X is equal to the positive amplitude. Press [9] [0] [ENTER] Press [AUTO PHASE] 6.
  • Page 17 9. Press <Sensitivity> Use the knob to change the sensitivity to 50 mV. Change the sensitivity back to 20 mV. 10. Press <Time Constant> Use the knob to change the time constant to 300 µs. Change the time constant to 3 ms. 11.
  • Page 18 The Basic Lock-in 13. Press [GAIN/TC] Display the Gain and Time Constant menu again. Press <Synchronous> to select <200 Hz. This turns on synchronous filtering whenever the detection frequency is below 200 Hz. Synchronous filtering effectively removes output components at multiples of the detection frequen- cy.

  • Page 19: Displays And Traces

    DISPLAYS and TRACES This measurement is designed to use the internal oscillator and an external signal source to explore some of the display types. You will need a synthesized function generator capable of providing a 100 mVrms sine wave at 1.000 kHz (the DS345 from SRS will suffice), BNC cables and a terminator appropriate for the gener- ator function output.
  • Page 20 Display the Display and Scale menu. The SR850 collects data in the form of traces. There are 4 definable traces and only these trace quantities may be displayed. The default definition of these traces is X, Y, R and and 4.
  • Page 21 Press [AUTO SCALE] Press the <± Range> softkey. This is the fifth softkey from the top. Press [1] [8] [0] [ENTER] 6. Press <Monitor> to select Input/Output. 7. Press <Format> to select Single. 8. Press [REF/PHASE] Press <Ref. Frequency> Use the knob to adjust the frequency slowly to try to stop the rotation of the signal vector.
  • Page 22 Displays and Traces Press <Ref. Slope> to select Rising Edge. 10. Press [DISPLAY/SCALE] Press <Format> to select Up/Down. 11. Press [TRACE/SCAN] Press <1 / 2 / 3 / 4> to select trace 3. Press the second softkey, next to the trace definition, to highlight the R.
  • Page 23 Using the keypad, enter a phase shift which is 45° greater than the displayed phase shift. Displays and Traces At a measured phase shift of 45°, trace 3 should equal cos45° or 0.707. This concludes this measurement example. You should have a feeling for the basic operation of the display types and trace definitions.
  • Page 24 Displays and Traces 2-12...

  • Page 25: Outputs, Offsets And Expands

    OUTPUTS, OFFSETS and EXPANDS This measurement is designed to use the internal oscillator to explore some of the basic lock-in outputs. You will need BNC cables and a digital voltmeter (DVM). Specifically, you will measure the amplitude of the Sine Out and provide analog outputs proportional to the measurement.
  • Page 26 DC output errors from the lock-in itself. The SR850 has no DC output errors and the offset is not required for most measurements. The offset affects both the displayed value of X and any analog output proportional to X.
  • Page 27 6. Connect the DVM to the X output on the rear panel. 7. Connect the DVM to the CH1 output on the front panel again. Press <Expand> Press [1] [ENTER] Press <Offset> Press [0] [ENTER] Outputs, Offsets and Expands The highlighted EXPD indicator turns on at the bottom left of the top display to indicate that the displayed trace is affected by an expand.
  • Page 28 Outputs, Offsets and Expands Press <Source> Use the knob to select Trace1. 8. Press [TRACE/SCAN] Press the second softkey, next to the trace definition, to highlight the X. Use the knob to change the numerator from X to 1. Press the second softkey twice to highlight the denominator (C) of the trace definition.

  • Page 29: Scans And Sweeps

    SCANS and SWEEPS This measurement is designed to use the internal oscillator to explore some of the basic lock-in functions. You will need BNC cables. Specifically, you will measure the response of the line notch filters by sweeping the internal reference frequen- cy and measuring the sine output.
  • Page 30 Highlight the trace number for the Top Bar graph. The SR850 acquires and displays data in the form of traces. The default definitions for the 4 traces are X, Y, R and . These definitions may be changed.
  • Page 31 Press <Sample Rate> Use the knob to select 32 Hz. Press <Scan Length> Press [1] [0] [0] [ENTER] Press <1 Shot/Loop> to select 1 Shot. 9. Press [START/CONT] Scans and Sweeps sets the amount of time the buffer will store and the length of any sweep.
  • Page 32 Scans and Sweeps 10. Press [DISPLAY/SCALE] Press <Format> to select Single. Press <Type> Use the knob to select Chart. Press <Type> again to highlight the Trace number. Use the knob to select Trace 3. Press [AUTO SCALE] 11. Press the <± Range> softkey. This is the fifth softkey from the top.
  • Page 33 X-axis position. Show the Display and Scale menu again. The SR850 can store up to 4 traces simultaneous- ly. In the default configuration, all 4 traces are stored. Let's take a look at the other traces.
  • Page 34 Scans and Sweeps 16. When the scan is complete, press [TRACE/SCAN]. Press <1 Shot/Loop> to select Loop. Press [PAUSE/RESET] Press [START/CONT] to start the scan again. 17. Press [PAUSE/RESET] ONCE. Press [START/CONT] 18. Press [DISPLAY/SCALE] Press <sec/div> (the last softkey). Use the knob to select 20 S/div.

  • Page 35: Using The Disk Drive

    The disk drive uses double-sided, double density (DS/DD) 3.5" disks. The disk capacity is 720k. The SR850 uses the DOS format. A disk which was formatted on a PC or PS2 (for 720k) may be used. Files written by the SR850 may be copied or read on a DOS computer.
  • Page 36 The Disk Drive 3. Press [AUTO PHASE] 4. Press [DISPLAY/SCALE] Press <Format> to select Single display. Press <Type> Use the knob to adjust the display type to Chart. 5. Press [TRACE/SCAN] Press <Scan Length> Press [1] [0] [0] [ENTER] Press <1 Shot/Loop> to select 1 Shot. 6.
  • Page 37 8. Press [DISK] Press <Disk Utils> Press <Disk Format> Press <Return> Press <Data Save> Press <File Name> Press [ALT] Press [D] [A] [T] [A] [1] [ALT] Press <Data Save> 9. Press [DISPLAY/SCALE] Press <Type/Trace> twice to highlight the trace number. Use the knob to change the trace number to 2.
  • Page 38 The Disk Drive Press <Data Save> 11. Press <Catalog> to select On. Press <Return> 12. Press [PAUSE RESET] 13. Press <Data Recall> Press <Catalog> to select On. Use the knob to select the first file. Press <Data Recall> 14. Press [DISPLAY/SCALE] Press <Format>...
  • Page 39 Use the knob to select the Chart display. Press <Full, Top or Bottom> to select Bottom. Use the knob to select the Chart display for the bottom display. Press [AUTO SCALE] Press [ACTIVE DISPLAY] 15. Press [DISK] Press <Data Recall> Press <Catalog>...
  • Page 40 The Disk Drive Press <Data Recall> Press [AUTO SCALE] This recalls the data file from disk and stores it in the active display trace. The active display trace is redefined to agree with the recalled data trace def- inition. In this case, the data is recalled into Trace 1 (since it is currently being shown on the active display).

  • Page 41: Storing And Recalling Settings

    STORING AND RECALLING SETTINGS 1. Turn the lock-in on while holding down the [ ] (backspace) key. Wait until the power-on tests are completed. Disconnect any cables from the lock-in. 2. Press [GAIN/TC] Press <Sensitivity> Use the knob to change the sensitivity to 100 mV.
  • Page 42 The Disk Drive Press <Catalog> Use the knob to select the settings file which you just saved. 6. Press <Settings Recall> Press [GAIN/TC] Display the disk catalog listing. Note that settings files have the file type SET. When the disk catalog is displayed, the knob high- lights a file.

  • Page 43: Aux Outputs And Inputs

    AUX OUTPUTS and INPUTS This measurement is designed to illustrate the use of the Aux Outputs and Inputs on the rear panel. You will need BNC cables and a digital voltmeter (DVM). Specifically, you will set the Aux Output voltages and measure them with the DVM. These outputs will then be connected to the Aux Inputs to simulate external DC voltages which the lock-in can measure.
  • Page 44 Aux Outputs and Inputs 5. Disconnect the DVM from Aux Out 1. Connect Aux Out 1 to Aux In 1 on the rear panel. 6. Press [TRACE/SCAN] Press the second softkey, next to the trace definition, to highlight the X. Use the knob to change the A parameter from X to AI1.
  • Page 45 Aux In 1. The chart display shows the history of the sweep. The SR850 can be used as a general purpose 4 channel digital chart recorder. The displays can be scaled vertically and horizontally with full cursor readouts.
  • Page 46 Aux Outputs and Inputs 2-34...

  • Page 47: Trace Math

    TRACE MATH This example is designed to familiarize the user with the trace math functions in the lock-in. You will need BNC cables and a 50 terminator. Specifically, you will record the input noise in a trace and perform various calculations with the trace. The internal oscillator will also be used to provide signal data for curve fits.
  • Page 48 Trace Math Use the knob to select 50 nV. 4. Press [TRACE/SCAN] Press <Sample Rate> Use the knob to change the sample rate to 16 Hz. 5. Press [DISPLAY/SCALE] Press <Format> to select Single. Press <Type> Use the knob to select Chart. Press <±...
  • Page 49 Press <Return> twice. 8. Press <Smooth> Press <17 point> Press [CURSOR] Use the knob to move the cursor past the left edge of the graph. The data will scroll to the right to display unsmoothed portions of the trace. Press <Return> 8.
  • Page 50 Trace Math Press <Do Calc.> Press [AUTO SCALE] Use the knob to select log10. Press <Do Calc.> Use the knob to select Press <Argument Type> to select Constant. Press <Constant Value> Press [2] [0] [ENTER] Press <Do Calc.> Press [AUTO SCALE] Press [CURSOR] Use the knob to read points from the graph.
  • Page 51 Press <1 Shot/Loop> to select 1 Shot. 13. Connect the Sine Out to the A input using a BNC cable. Wait until the value of X reaches 1 V. 14. Press [DISPLAY/SCALE] Press <Format> to select Single. Press the <± Range> softkey. This is the fifth softkey from the top.
  • Page 52 Trace Math Press <Left Limit> Use the knob to position the cursor 3 divisions to the right of the left limit. Press <Right Limit> Move the cursor farther to the right. Press <Do Fit> 17. Press any key to continue. Press any key to continue.
  • Page 53 Remove the fit from the graph. The math functions are very powerful data analy- sis tools. Together with the flexible trace defini- tions, the SR850 can perform complex data acqui- sition and analysis tasks. 2-41 Trace Math...
  • Page 54 Trace Math 2-42...

  • Page 55: What Is A Lock-In Amplifier

    The signal is V where V is the signal amplitude. The SR850 generates its own sine wave, shown as the lock-in reference below. The lock-in refer- ence is V sin(...
  • Page 56 R measures the signal amplitude and does not . Since depend upon the phase between the signal and lock-in reference. A dual-phase lock-in, such as the SR850, has two PSD's, with reference oscillators 90° apart, and can measure X, Y and R directly. In addition, the phase...

  • Page 57: What Does A Lock-In Measure

    S(t) = 1.273sin( t) + 0.4244sin(3 t) + 0.2546sin(5 t) + ... where = 2 f. The SR850, locked to f will single out the first component. The measured signal will be 1.273sin( t), not the 2V pk-pk that you'd meas- ure on a scope.
  • Page 58 SR850 Basics...

  • Page 59: The Sr850 Functional Diagram

    Lock-In Amplifier is shown below. The functions in the gray area are handled by the digital signal pro- cessor (DSP). We'll discuss the DSP aspects of the SR850 as they come up in each functional block description. Low Noise Differential...
  • Page 60 SR850 Basics...

  • Page 61: Reference Channel

    (at zero phase) to the detected edge. Internal Oscillator The internal oscillator in the SR850 is basically a 100 kHz function generator with sine and TTL sync outputs. The oscillator can be phase-locked to the external reference.

  • Page 62: Harmonic Detection

    Noise at nearby frequencies now appears near DC and affects the lock-in output. Phase noise in the SR850 is very low and general- ly causes no problems. In applications requiring no phase jitter, the internal reference mode should be used.

  • Page 63: Phase Sensitive Detectors

    (90° apart). Digital PSD vs Analog PSD The phase sensitive detectors (PSD's) in the SR850 act as linear multipliers, that is, they multi- ply the signal with a reference sine wave. Analog PSD's (both square wave and linear) have many problems associated with them.
  • Page 64 SR850 Basics 3-10...

  • Page 65: Time Constants And Dc Gain

    Each PSD can be fol- lowed by up to four filter stages for up to 24 dB/oct of roll off. Since the filters are digital, the SR850 is not limited to just two stages of filtering.
  • Page 66 The synchronous filter only notches multiples of the reference frequency, the noise is filtered by the normal filters. The SR850 can provide time constants as long as 30000 seconds at reference frequencies below 200 Hz. Obviously you don't use long time con- stants unless absolutely necessary, but they're available.

  • Page 67: Dc Outputs And Scaling

    18°/Volt or 180°=10V. X, Y and R Output Offset and Expand The SR850 has the ability to offset the X, Y and R outputs. This is useful when measuring deviations in the signal around some nominal value. The offset can be set so that the output is offset to zero.
  • Page 68 10 µV greater than the 0.9 mV nominal. (Offset = 0.9 and expand =10). The X and Y offset and expand functions in the SR850 are output functions, they do NOT affect the calculation of R or . R has its own output offset and expand.
  • Page 69 The octaves are defined as follows, 62.5 Hz - 125 Hz 125 Hz - 250 Hz 250 Hz - 500 Hz 500 Hz - 1000 Hz 1 kHz - 2 kHz 4 kHz - 8 kHz 8 kHz - 16 kHz SR850 Basics 3-15...
  • Page 70 SR850 Basics 3-16...

  • Page 71: Dynamic Reserve

    This comes about because the DC output amplifier is running at very SR850 Basics high gain and low frequency noise and offset drift at the PSD output or the DC amplifier input will be amplified and appear large at the output.
  • Page 72 To set a scale, the SR850's output noise at 100 dB dynamic reserve is only measurable when the signal input is grounded. Let's do a simple experi- ment.

  • Page 73: Signal Input Amplifier And Filters

    Constant menu. The ENBW depends upon the time constant and filter roll off. For example, sup- pose the SR850 is set to 5 µV full scale with a 100 ms time constant and 6 dB/oct of filter roll off. The lock-in will measure the input noise with an ENBW of 2.5 Hz.

  • Page 74: Input Impedance

    This filter is transparent to the user. Input Impedance The input impedance of the SR850 is 10 M . If a higher input impedance is desired, then the SR550 remote preamplifier must be used. The SR550 has...

  • Page 75: Input Connections

    100 dB CMRR of the lock-in input, but noise on only the shield is not rejected at all. Experiment SR850 Lock-In Signal Source Grounds may be at different potentials Differential Voltage Connection (A-B) The second method of connection is the differen- tial mode.
  • Page 76 SR850 Basics Current Input (I) The current input on the SR850 uses the A input BNC. Voltage or current input is chosen in the INPUT menu. The current input has a 1 k impedance and a current gain of either 10 Volts/Amp.

  • Page 77: Intrinsic (Random) Noise Sources

    Ohms, and f is the bandwidth in Hz. f is the bandwidth of the measurement. Since the input signal amplifier in the SR850 has a bandwidth of approximately 300 kHz, the effective noise at the amplifier input is V noise or 350 R nV pk-pk.
  • Page 78 SR850 Basics 3-24...

  • Page 79: External Noise Sources

    /dt) in the loop connecting the detector to the experiment. This is like a transformer with the experiment-detector winding. Experiment noise noise is the stray 3-25 SR850 Basics = 120 V. C can be noise stray is 0.009 pF. stray ). Do not bring stray...

  • Page 80: Resistive Coupling Or Ground Loops

    SR850 Basics Cures for inductively coupled noise include: 1) Removing or turning off the interfering noise source. 2) Reduce the area of the pick-up loop by using twisted pairs or coaxial cables, or even twisting the 2 coaxial cables used in differential connections.

  • Page 81: Noise Measurements

    The noise is simply the standard deviation (root of the mean of the squared deviations)of the meas- ured X, Y or R . The SR850 can measure this noise exactly by recording the output quantity on a chart display and then calculating the standard deviation using the trace math functions.
  • Page 82 SR850 Basics Which method you use depends upon the require- ments of the experiment. R noise The quantity Rn can be somewhat hard to under- stand. For example, suppose X and Y are equally noisy and centered about zero. The values of R are always positive (magnitude) and thus average to a nonzero value.

  • Page 83: Power Button

    Power Button Video Display POWER BUTTON The SR850 is turned on by pushing in the power button. The video display may take a few seconds to warm up and become visible. Adjust the bright- ness until the screen is easily readable.The model, firmware version and serial number of the unit are displayed when the power is turned on.

  • Page 84: Soft Keys

    Double sided, double density disks should be used. The disk capacity is 720k bytes formatted. The disk format is DOS compatible. Disks written by the SR850 may be read by PC compatible computers equipped with a 3.5" drive and DOS 3.0 or higher.
  • Page 85 Front Panel Ch1 & Ch2 Outputs The Channel 1 and Channel 2 outputs can be con- figured to output a voltage from -10 V to +10 V proportional to X, Y, R, , or Traces 1 through 4. ±10 V is full scale. The outputs can source 10 mA maximum.
  • Page 86 Front Panel...

  • Page 87: Screen Display

    Display 10.000 e-3 Stop DEFAULT DISPLAY The SR850's default display is shown above. This is the display format in effect when the unit is turned on. This screen resembles a "normal" lock-in front panel. The lock-in setup is displayed across the top of the screen.

  • Page 88: Data Traces

    Screen Display DATA TRACES The SR850 collects and displays data in the form of traces. There are four data traces which may be defined. Each trace is defined as A•B/C where the parameters A, B, and C are chosen from X, Y, R, , Xnoise, Ynoise, Rnoise, Aux Inputs 1-4, Frequency, and unity (1).
  • Page 89 SINGLE and DUAL TRACE DISPLAYS The screen can be formatted as a single trace (Single) display or a dual trace (Up/Down) display. The screen format is selected in the DISPLAY/ SCALE menu. There are three displays which may be configured, the Single screen display and the Top and Bottom displays for the split screen.
  • Page 90 Screen Display...

  • Page 91: Bar Graphs

    BAR GRAPHS The most commonly used display type is the Bar graph with large numeric readout. This display most closely resembles a "normal" lock-in. The bar graph display is shown below. The bar graph only occupies half of the screen, even when the screen format is full height. Thus, it generally makes sense to use the bar graph in split screen mode and show two bar graphs.

  • Page 92: Polar Graphs

    POLAR GRAPHS The polar graph is a convenient way to view magnitude and phase. The signal is represented as a vector on an X-Y coordinate axes. The full screen polar display is shown below. The split screen polar graph is half as big.

  • Page 93: Strip Charts

    STRIP CHARTS Chart displays are used to view stored traces. Only stored traces have a time history, thus, only stored traces may be displayed on a chart. The full screen chart display is shown below. If the split screen format is used, the chart will display half as many vertical divisions but will be the same as the full size display in all other aspects.
  • Page 94 Screen Display Data Scrolling The chart display acts like a strip chart recorder where the pen is drawing the most recent data. For example, if the sample rate is 1 Hz (1 point taken per second) and the horizontal scale is 10 S/div, then the graph displays 100 data points (10 divisions x 10 points per division).

  • Page 95: Trace Scans, Sweeps And Aliasing

    If a graph or record of a trace over time is desired, then that trace's data must be stored. The SR850 can record up to 64000 data points in memory. The data buffer can store 64000 points of a single trace, 32000 points of two traces, or 16000 points of all four traces.
  • Page 96 Screen Display the scan length is only meaningful is parameters are being swept. Once the trace buffer has looped around, the oldest point (at any time) is at bin#0 and the most recent point is at bin#k where k is the buffer length (minus 1).

  • Page 97: Settings And Input/Output Monitor

    SETTINGS & INPUT/OUTPUT MONITOR The upper two lines of the screen are the monitor display (see the screen on pg. 4-5). The lock-in settings (sensitivity, time constant, etc.) or the lock-in signal measurements (X, Y, R, , and the Aux Inputs) may be monitored. Use the DISPLAY menu to select the type of monitor (Settings or Input/Output).

  • Page 98: Status Indicators

    Sine (Ext S), Rising TTL edge (Ext +), or Falling TTL edge (Ext -). LOCK • UNLOCK The UNLOCK indicator turns on if the SR850 can not lock to the external reference. LOCK is dis- played when the SR850 is successfully locked to the reference.
  • Page 99 (usually on). This indicator is on whenever a GPIB Service Request is generated by the SR850. SRQ stays on until a serial poll is completed. Indicates that the ALTERNATE keypad is in use.
  • Page 100 Screen Display 4-18...

  • Page 101: Keypad

    MENU KEYS All operating parameters of the SR850 are grouped into function menus. The ten menu keys select which menu of parameters is displayed next to the six soft keys.

  • Page 102: Additional Menus

    [DISPLAY/SCALE] Select full screen or split screen display, settings or input/output monitor, and display scaling. [AUX OUTPUTS] Program the four Aux Output voltages and sweep limits. Also select scan starts with trigger. [MATH] Provides data smoothing, curve fitting, statistical analysis, and calculator functions for operating on stored data traces.

  • Page 103: Cursor

    [PAUSE/RESET] will erase the data buffer whenever data acquisition is Paused or Done. To clear a buffer while a scan is in progress, two presses of the [PAUSE/RESET] key are required. However, at the end of a single shot scan, the data acquisition will be Done.

  • Page 104: Cursor Max/Min

    There is no truly reliable way to automatically setup a lock-in amplifier for all possible input sig- nals. In most cases, the following procedure should setup the SR850 to measure the input signal. 1. Press [AUTO GAIN] to set the sensitivity.

  • Page 105: Print To A Printer

    Pressing [AUTO SCALE] when a chart graph is the active display will automatically set the vertical range and center value to display the entire range of the data. [AUTOSCALE] does not affect the hor- izontal scaling. [AUTOSCALE] only operates on the data which is presently displayed on the graph.
  • Page 106 Keypad 4-24...

  • Page 107: Rear Panel

    Also, a serial plotter with HPGL compatible graph- ics may be connected to the RS232 port. The SR850 will drive the plotter to generate plots of the screen graph. Use the SYSTEM SETUP menu to configure the SR850 for use with a serial plotter.

  • Page 108: Rear Panel Bnc Connectors

    TRIG IN AUX IN 1-4 (A/D Inputs) These are auxiliary analog inputs which can be digitized by the SR850. The range is -10V to +10V and the resolution is 16 bits (1/3 mV). The input impedance is 1 MΩ .

  • Page 109: Ttl Sync Output

    (standard 9 pin D connectors) from the preamp to the rear panel preamp connec- tor on the SR850. Use BNC cables to connect the A output from the preamp to the A input of the SR850. The B output from the preamp (preamp ground) may be connected to the B input of the SR850.
  • Page 110 Rear Panel 4-28...
  • Page 111 Fixed or Swept Outputs Output Voltage and Sweep Limits Cursor Setup Max, Min or Mean Seeking Cursor Region Width Vertical Grid Linked Cursors Cursor Readout SR850 MENUS Edit Mark Marker Labels Cursor To Next Mark Math Smooth Fit Line, Exponential or Gaussian Calculator...

  • Page 112: Default Settings

    SR850 Menus DEFAULT SETTINGS If the [ ] (backspace) key is held down when the power is turned on, the lock-in settings will be set to the defaults shown below rather than the settings that were in effect when the power was last turned off. The default settings may also be recalled using the RST command over the computer interface.

  • Page 113: Reference And Phase

    Reference and Phase Ref. Phase REFERENCE 12.345 deg. Rotate 90 deg. Ref. Source Internal Ref Frequency 50.000 Hz Harmonic Sine Output 0.100 V rms Reference Phase REFERENCE AND PHASE MENU The Reference and Phase menu sets the reference source, phase shift, and detection harmonic.

  • Page 114: Reference Source

    When either TTL Rising Edge or TTL Falling Edge is selected, the SR850 locks to the selected edge of a TTL square wave or pulse train. For reliable operation, the TTL signal should exceed 3.5 V when high and be less then 0.5 V when low.

  • Page 115: Internal Sweeps

    Internal Sweep When the reference source is Internal Sweep, the SR850's Ref. Source Internal Sweep Sweep Menu: Sweep Type linear Sweep Limits Start: 1.0000 kHz Sweep Limits The upper field is the sweep start frequency and the lower Stop: 2.0000 kHz...
  • Page 116 Sine Output The SR850 can detect signals at harmonics of the reference frequency. The SR850 multiplies the input signal with digital sine waves at a multiple of the reference. Only signals at this harmonic will be detected. Signals at the original reference frequency are not detected and are attenuated as if they were noise.

  • Page 117: Input And Filters Menu

    The Input and Filters menu sets the input signal source and configura- tion. The input notch filters are also selected in this menu. See the SR850 Basics section for a discussion of the different input configura- tions and the signal filters.
  • Page 118 10 Hz or so. If the reference frequency is 70 Hz, do not use the 60 Hz notch filter! The signal will be attenuated and the phase shifted. See the SR850 Basics section for a discussion of when these filters improve a measurement.

  • Page 119: Gain And Time Constant Menu

    The Gain and Time Constant menu sets the full scale sensitivity and dynamic reserve. The low pass filter time constant and slope are also selected in this menu. See the SR850 Basics section for a discussion of gain, time constants and dynamic reserve.
  • Page 120 Reserve This key selects either maximum, minimum or manual dynamic reserve. When the reserve is maximum, the SR850 automatically selects the max- imum reserve available at the present full scale sensitivity. When the reserve is minimum, the minimum available reserve is selected. The dynamic reserve is displayed in the settings display at the top of the screen (if selected in the DISPLAY/SCALE menu).

  • Page 121: Time Constant

    Gain and Time Constant Menu signal will obscure the signal at the reference and make detection difficult if not impossible. See the SR850 Basics section for more information. This key selects the Manual Reserve entry field for knob adjustment. Keypad entry is not allowed for this parameter. This menu box is availa- ble only if manual reserve is selected above.
  • Page 122 (ENBW) of the low pass filter. This is the measurement band- width for Gaussian noise and depends upon the time constant and filter slope. (See the Noise discussion in the SR850 Basics section.) Analog Outputs with Short Time Constants...
  • Page 123 The synchronous filter does NOT attenuate broadband noise (except at the harmonic frequencies). The low pass filters remove out- puts due to noise and interfering signals. See the SR850 Basics section for a discussion of time constants and filtering.
  • Page 124 Gain and Time Constant Menu Use of the synchronous filter results in a reduction in amplitude resolution. 5-14...

  • Page 125: Output And Offset Menu

    OUTPUT AND OFFSET MENU The Output and Offset menu selects the CH1 and CH2 outputs and sets the X, Y and R offsets and expands. See the SR850 Basics section for a discussion of the DC outputs and scaling. OUTPUT...

  • Page 126: Output Offset And Expand

    Output and Offset Menu Output Offset and Expand The X, Y and R outputs may be offset and expanded. See the SR850 Basics section for a complete discussion of scaling, offsets and expands. Briefly, X, Y and R analog outputs (either the rear panel X and Y or the...

  • Page 127: Trace And Scan Menu

    Sample Rate Scan Length The SR850 collects and displays data in the form of traces. There are four data traces which may be defined. Each trace is defined as A•B/C where the parameters A, B and C are chosen from X, Y, R, , Xnoise, Ynoise, Rnoise, Aux Inputs 1-4 (rear panel), Frequency, and unity (1).

  • Page 128: Sample Rate

    The noise values are calculated by the SR850 and represent the noise of the signal in the equivalent noise bandwidth of the low pass filter time con- stant.

  • Page 129: Scan Length

    Trace and Scan Menu Aliasing effects can occur whenever the trace being sampled contains signals at frequencies greater than twice the sample rate. The effect is most noticeable when trying to sample an output whose frequency is a multiple of the sample rate. Generally, the highest possible sample rate should be used given the desired scan length and the buffer size.
  • Page 130 Trace and Scan Menu 5-20...

  • Page 131: Display And Scale Menu

    Display and Scale Format Single Up/Down Monitor Settings Input/Output Display Scale Full Bottom Type: Chart Trace: 1 ± 1.000 e0 10 S /div Format Monitor Display Scale DISPLAY AND SCALE MENU The Display and Scale menu selects the screen format, the displayed traces, and the display types.
  • Page 132 Display and Scale Menu Full, Top or Bottom Display Type and Trace Range and Center Pressing this key selects which display's type, trace and scaling will be adjusted and displayed in this menu box. If the format is full screen, the top and bottom displays can not be selected.
  • Page 133 Display and Scale Menu Seconds/div Chart graphs have a horizontal scale which determines how much of the data buffer will be displayed. The horizontal scale is the number of sec- onds per division across the graph. By changing the horizontal scale, the entire trace buffer can be displayed at once or a small portion may be expanded.
  • Page 134 Display and Scale Menu 5-24...

  • Page 135: Aux Outputs Menu

    Aux Outputs Aux. Output Fixed Linear Voltage 2.000 V Trigger Starts? Aux Outputs Aux Out 1, 2, 3 or 4 Fixed, Log or Linear AUX OUTPUTS MENU The Aux Outputs menu programs the rear panel auxiliary D/A outputs. The outputs may be set to fixed voltages or programmed to sweep. In addition, the Trigger input can be configured to start scans.
  • Page 136 Aux Outputs Menu Voltage Sweep Limits This menu box displays the fixed voltage at the selected aux output. This menu box is only displayed if the output is Fixed. If the output is Fixed, pressing this key will select the voltage as the active entry field.
  • Page 137 Sweep Limits Start Start: 1.000 V Stop: Stop 2.000 V Offset: 0.000 V Offset Trigger Starts? A log sweep from a higher voltage to a lower voltage is just the reverse progression as the sweep from lower to higher. More time will be spent at lower voltages.
  • Page 138 Aux Outputs Menu 5-28...

  • Page 139: Cursor Setup Menu

    Cursor Setup Cursor Seek Mean Cursor Width Narrow Spot Wide Vert Grid Divs None Cursor Control Linked Separate Cursor Readout Delay Time Fsweep Cursor Seek CURSOR SETUP MENU The Cursor Setup menu is activated with the [CURSOR SETUP] key in the Entry area of the keypad.

  • Page 140: Cursor Control

    Cursor Setup Menu Cursor Width Vert Grid Divs Cursor Control Cursor Readout This function selects the width of the cursor region defined by the vertical dashed lines on the chart display. Cursors are available only for chart displays. Each display (full, top or bottom) has its own cursor width. Narrow is 1/2 of a division, Wide is 1 division, and Spot is a single hori- zontal position on the graph (the cursor is a single dashed line).

  • Page 141: Edit Mark Menu

    Edit Mark Marker Insert: Edit: Delete: Cursor to Next: Previous: Insert Mark EDIT MARK MENU The Edit Mark menu is activated with the [EDIT MARK] key in the Entry area of the keypad. This menu is used to label marks in the data buffer. See the discussion on chart graphs in the Operation section for more information about marks.

  • Page 142: Delete Mark

    Edit Mark Menu Edit Mark Entry Mode Overstrike Insert Character Space: Delete: Backspace: Marker Changes Abandon Changes Press this key to abandon any changes made to the mark Abandon: Save: Delete Mark Cursor to Next Cursor to Previous This key activates a submenu which allows marks to be labelled and viewed.

  • Page 143: Math Menu

    Math Math Smooth: Fit: Calc: Stats: Math Keys The Math menu is used to smooth, fit, change and analyze trace data. Math functions only operate on the data which is displayed within the active display. MATH Each Math key activates a sub menu. Each sub menu is described in detail in the following pages.

  • Page 144: Smooth

    Math Menu Smooth 25 point: 21 point: 17 point: 11 point: 5 point: Return: 25 point 21 point 17 point 11 point 5 point Return The Smooth sub menu will smooth the data within the active chart dis- play using the Savitsky-Golay algorithm. For details on the Savitsky- Golay smoothing technique, see Abraham Savitsky and Marcel J.

  • Page 145: View Parameters

    Do Fit: Type of Fit Line Gauss View Params: Limits Left: Right: Return: Do Fit Type of Fit View Parameters The Fit sub menu allows the user to fit one of three curves to the data within the active chart display - lines, exponentials, and Gaussians. Fit- ting is done using the Marquardt 'Gradient-expansion' algorithm to mini- mize chi-squared.
  • Page 146 Math Menu re-entered, the View Parameters function will re-display the best fit curve and the parameter window. Both the Do Fit and View Parameters functions result in a display screen like the one shown below. Full Scale = 100 mV Dyn Reserve = 23 dB Trace 2 center = 0.0...
  • Page 147 Limit Markers Return Full Scale = 100 mV 100 mS Dyn Reserve = 23 dB 12 dB/oct Line Trace 2 10 S /div center = 0.0 50.00 e-3 Intrnl Fr= 100.00 Hz Done LOCK Harmonic= 1 The Return key will return to the main Math menu. Re-entering the Fit menu and using the View Parameters function will re-display the most recent fit.

  • Page 148: Operation

    Math Menu Calc MATH Do Calc: Operation Argument Type Trace Constant Constant Value Cursor Value to Arg: Return: Do Calc Operation The Calculation sub menu allows the user perform simple arithmetic cal- culations with data displayed in the active chart. Operations are per- formed only on the data within the chart, not the entire trace buffer.
  • Page 149 Argument Type Argument Type Trace Constant Constant Value Pressing the Constant Value key activates the constant Constant Value Cursor Value to Arg: Cursor Value to Arg. The Cursor Value to Arg key will copy the trace value of Argument Type Trace Constant Trace...

  • Page 150: Stats

    Math Menu Stats Do Stats: Limits Left: Right: Return: Do Stats Left and Right Limit Return The Stats sub menu calculates a variety of statistical information about a chart display calculation region defined by the Left and Right Limits. MATH Stats Pressing this key starts the actual calculation.

  • Page 151: Disk Menu

    Files are saved as DOS files and can be read by a DOS compatible com- puter with a 3.5" disk drive. The SR850 uses double sided, double density disks (DS/DD). Do not use high density (DS/HD) disks. The maximum number of files allowed on a disk is 114. This is the DOS limitation on the number of directory entries in the root directory.
  • Page 152 The ASCII format is a convenient way to transfer data to other programs on a PC. The file is a simple DOS text file. ASCII files may not be recalled on the SR850! File Name This key activates the File Name entry field. File names are entered using the alternate keypad.
  • Page 153 Full Scale = 10 mV 100 mS Dyn Reserve = 3 dB 12 dB/oct Line Name Type Size ABCD 1894 02/07/91 02/22/91 TEST 03/13/91 SPECT1 16384 04/11/91 MYDATA 16384 Free = 720280 bytes Stop Intrnl Fr= 100.00 Hz LOCK Harmonic= 1 5-43 Disk Menu Data...

  • Page 154: Recall Data

    Disk Menu Recall Data The Recall Data submenu is used to recall data from a binary disk file into the trace which is displayed by the active display. For example, if the full screen display is a chart showing Trace 2, then recalling a trace from disk will read the file into Trace 2.
  • Page 155 Data Recall: File Name TEST Catalog Catalog On/Off Return: Recall Data Pressing this key will recall the trace data and instrument state from the file specified in the File Name field. If the file specified is not on the disk or is not a data file, then an error message will appear.

  • Page 156: Save Settings

    Disk Menu Save Settings Setting Save: File Name TEST Catalog Return: The Save Settings submenu is used to save the lock-in settings to a disk file. The settings include all parameters which are set with the menus. Save Settings Pressing this key will save the current lock-in settings to the file specified in the File Name field.

  • Page 157: Recall Settings

    Recall Settings Recall Settings Setting Recall: File Name TEST Catalog Return: The Recall Settings submenu is used to recall the lock-in settings from a disk file. The settings include all parameters which are set with the menus. Pressing this key will read the settings information from the file specified in the File Name field.

  • Page 158: Disk Utilities

    Disk Menu Disk Utilities File Erase: Disk Format: File Name TEST Catalog Return: The Disk Utilities submenu contains the Format Disk and Erase File func- tions. These functions should be used with care since disk data will be erased. The catalog screen may be displayed with this submenu if a formatted disk is in the drive.

  • Page 159: System Setup

    System Setup Settings: Plot: Info: Hardware Test: Setup Keys SYSTEM SETUP MENU The System Setup menu is used to configure the system parameters. The Settings submenu configures the printer, plotter and computer inter- faces, and the screen, sound and clock/calendar parameters. The Plot submenu is used to plot the screen display to an HPGL compatible plot- ter.

  • Page 160: Settings

    System Setup Menu Settings Settings Settings Com: Screen: Sound: Time: Plotter: Printer: More: Return: Return: Settings Keys The Settings menu is used to configure the printer, plotter and computer interfaces, and to set the screen, sound and clock/calendar parameters. SYSTEM SETUP Settings Communications...

  • Page 161: Gpib Communications

    View Queues Return The SR850 only outputs data to one interface at a time. Commands may be received over both interfaces but responses are directed only to the interface selected by this key. Make sure that the Output interface is set correctly before attempting to program the SR850 from a computer.
  • Page 162 Yes. In this mode, the front panel is not locked out when the unit is in the REMOTE state. If the SR850 is in the REMOTE state, the [HELP] key returns the unit to local front panel control. Return The Return key will return to the Setup Communications menu.
  • Page 163 View Queues Return The last 256 characters received or transmitted by the SR850 may be displayed to help find programming errors. The View Queues key will dis- play the interface buffers at the time the key is pressed. This screen is updated regularly to display new interface activity.

  • Page 164: Key Click

    System Setup Menu Setup Sound Key Click Alarms Return: Key Click Alarms Return The Setup Sound key activates the sound submenu. Key click and alarms are enabled and disabled in this menu. SYSTEM SETUP Settings Sound This key turns the key click on and off. This key enables and disables the audible alarms.

  • Page 165: Plot Mode

    Cursor Pen Return Return The SR850 can drive either an RS232 or GPIB interface plotter. The plot- ter must be HP-GL compatible. This function selects which interface to use. The plotter connects to the RS232 or GPIB connector on the rear panel.
  • Page 166 In this mode, the plotter must be the only device attached to the SR850 GPIB interface. This key toggles the Plot Speed. Normally, when plotting on paper, the Fast Plot Speed is used. When plotting on transparencies or other non- standard media, the Slow plot speed may be better.

  • Page 167: Setup Printer

    PCX file on the disk. The files are automati- cally named SCRNXXXX.PCX. PCX files can be imported directly into many paint and draw programs on a PC. This allows SR850 charts and graphs to be easily incorporated into documents on a PC. Press the [PRINT] key to print the screen on the printer or to a file.
  • Page 168 System Setup Menu Setup Screen Move Right: Left: Down: Return: Move Right Move Left Move Up Move Down Return The Setup Screen submenu is used to adjust the position of the display on the screen. The display area may be moved left, right, up and down. SYSTEM SETUP Settings...

  • Page 169: Setup Time

    Setup Time Time 03 : 45 : 12 Date 03 / 15 / 91 Return: Time Date Return The Setup Time key activates the clock/calendar submenu. The time and date are used to label all screen prints and plots as well as disk files. This menu is used to check or change the time and date.
  • Page 170 System Setup Menu 5-60...

  • Page 171: Plot

    Plot Plot All: Trace: Cursor: Abort Plot: Return: Plot All Plot Trace Plot Cursor Plot Abort Return The Plot submenu is used to plot the screen display to an HPGL compat- ible plotter. Use the Plotter Settings menu to configure the plotter interface.
  • Page 172 System Setup Menu 5-62...

  • Page 173: Info

    This key displays the SR850 specifications. This key displays information about Stanford Research Systems, Inc. This key displays information about the use of the SR850. This key displays a list of the remote commands available. This key displays an explanation of the remote programming status bytes.
  • Page 174 System Setup Menu 5-64...

  • Page 175: Test Hardware

    Return: Keypad Test Keyboard Test Knob Test The Test submenu allows the user to test various features of the SR850 such as the keypad, knob, screen, memory, etc. Use the More softkey to select the second test menu screen. SYSTEM...

  • Page 176: Printer Test

    The loop back adapter is simply a mating connector with pins 2 and 3 connected so characters transmit- ted by the SR850 will be received by the SR850. The Memory Test key activates a memory test submenu. Select the desired memory test.

  • Page 177: Status Indicators And Queues

    Setup GPIB menu and may be set between 0 and 30. COMMUNICATING WITH RS232 The SR850 is configured as a DCE ( transmit on pin 3, receive on pin 2) device and supports CTS/ DTR hardware handshaking. The CTS signal (pin...

  • Page 178: Interface Ready And Status

    "?" to the command mnemonic and omitting the desired parameter from the command. Values returned by the SR850 are sent as a string of ASCII characters terminated by a carriage return <cr> on RS232 and by a line-feed <lf> on GPIB. If...

  • Page 179: Detailed Command List

    DETAILED COMMAND LIST The four letter mnemonic in each command sequence specifies the command. The rest of the sequence con- sists of parameters. Multiple parameters are separated by commas. Parameters shown in { } are optional or may be queried while those not in { } are required. Commands that may be queried have a question mark in parentheses (?) after the mnemonic.

  • Page 180: Reference And Phase

    Remote Programming REFERENCE and PHASE COMMANDS PHAS (?) {x} FMOD (?) {i} FREQ (?) {f} SWPT (?) {i} SLLM (?) {f} SULM (?) {f} RSLP (?) {i} The PHAS command sets or queries the reference phase shift. The parameter x is the phase (real number of degrees). The PHAS x com- mand will set the phase shift to x.
  • Page 181 HARM (?) {i} SLVL (?) {x} The HARM command sets or queries the detection harmonic. This parameter is an integer from 1 to 32767. The HARM i command will set the lock-in to detect at the i harmonic of the reference frequency. The value of i is limited by ixf 102 kHz.

  • Page 182: Input And Filter

    Remote Programming INPUT and FILTER COMMANDS ISRC (?) {i} IGAN (?) {i} IGND (?) {i} ICPL (?) {i} ILIN (?) {i} The ISRC command sets or queries the input configuration. The parame- ter i selects A (i=0), A-B (i=1) or I (i=2). The IGAN command sets or queries the conversion gain of the current input.

  • Page 183: Gain And Time Constant Commands

    GAIN and TIME CONSTANT COMMANDS SENS (?) {i} RMOD (?) {i} RSRV (?) {i} OFLT (?) {i} The SENS command sets or queries the sensitivity. The parameter i selects a sensitivity below. sensitivity 2 nV/fA 5 nV/fA 10 nV/fA 20 nV/fA 50 nV/fA 100 nV/fA 200 nV/fA...
  • Page 184 Remote Programming OFSL (?) {i} SYNC (?) {i} Time constants greater than harmonic x ref. frequency (detection frequency) exceeds 200 Hz. Time constants shorter than the minimum time constant (based upon the filter slope and dynamic reserve) will set the time constant to the minimum allowed time constant.

  • Page 185: Output And Offset

    OUTPUT and OFFSET COMMANDS FOUT (?) i {, j} OEXP (?) i {, x, j} AOFF i The FOUT command sets or queries the front panel (CH1 and CH2) output sources. The parameter i selects CH1 (i=1) or CH2 (i=2) and is required.

  • Page 186: Trace And Scan

    Remote Programming TRACE and SCAN COMMANDS TRCD (?) i {, j, k, l, m} SRAT (?) {i} SLEN (?) {x} SEND (?) {i} TRIG The TRCD command sets or queries the trace definitions. The parameter i selects the trace number (1, 2, 3 or 4) and is required. The TRCD i, j, k, l, m command defines trace i to quantity j times quantity k divided by quantity l and the trace will be stored (m=1) or not stored (m=0).

  • Page 187: Display And Scale

    DISPLAY and SCALE COMMANDS ASCL ADSP (?) {i} SMOD (?) {i} MNTR (?) {i} DTYP (?) i {, j} DTRC (?) i {, j} DSCL (?) i {, x} DOFF (?) i {, x} The ASCL command auto scales the active display. This command is just like pressing the [AUTO SCALE] key.
  • Page 188 Remote Programming DHZS (?) i {, j} RBIN? i The DHZS command sets or queries the display horizontal scale. The parameter i selects the Full (i=0), Top (i=1) or Bottom (i=2) display and is required. The parameter j selects a scale listed below. An error is gener- ated if the DHZS command tries to set the horizontal scale of a display which is not on the screen.

  • Page 189: Cursor Commands

    CURSOR COMMANDS CSEK (?) {i} CWID (?) {i} CDIV (?) {i} CLNK (?) {i} CDSP (?) {i} CMAX CURS? i CBIN (?) {i} The CSEK command sets or queries the cursor seek mode of the active display. The parameter i selects Max (i=0), Min (i=1) or Mean (i=2). Each display has its own cursor seek mode.

  • Page 190: Mark

    Remote Programming MARK COMMANDS MARK CNXT CPRV MDEL MACT? MBIN? i MTXT (?) i {,s} The MARK command is just like pressing the [MARK] key. A mark will be placed in the data buffer at the next sample. This command has an effect only when a scan is in progress.

  • Page 191: Aux Input And Output

    AUX INPUT and OUTPUT COMMANDS OAUX? i AUXM (?) i {, j} AUXV (?) i {, x} SAUX (?) i {, x, y, z} TSTR (?) {i} The OAUX? command queries the Aux Input values. The parameter i selects an Aux Input (1, 2, 3 or 4) and is required. The Aux Input voltages are returned as ASCII strings with units of Volts.

  • Page 192: Math

    Remote Programming MATH COMMANDS The math functions operate on the trace which is graphed in the active display. If the display type is polar, then the trace most recently displayed (in a bar or chart) will be used. If the active display trace is not stored, then the math functions will generate an error and have no effect.
  • Page 193 CALC CAGT (?) {i} CTRC (?) {i} CARG (?) {x} FTYP (?) {i} FITT i, j PARS ? i STAT i, j SPAR ? i The CALC command starts the calculation selected by the COPR com- mand. This may take some time. Use a status query command to detect when the calculation is done.

  • Page 194: Store And Recall

    Remote Programming STORE AND RECALL FILE COMMANDS When using file commands, the status byte should be queried after the command is sent to check if the com- mand generated an error. Common sources of errors are file not on disk, no space on disk, and no disk in drive.

  • Page 195: Setup

    SETUP COMMANDS OUTX (?) {i} OVRM (?) {i} KCLK (?) {i} ALRM (?) {i} THRS (?) {i} TMIN (?) {i} TSEC (?) {i} DMTH (?) {i} DDAY (?) {i} DYRS (?) {i} PLTM (?) {i} PLTB (?) {i} PLTA (?) {i} PLTS (?) {i} PNTR (?) {i} The OUTX command sets the output interface to RS232 (i=0) or GPIB...
  • Page 196 Remote Programming PNGD (?) {i} PNAL (?) {i} PNCR (?) {i} PRNT (?) {i} The PNGD command sets or queries the grid pen number. The pen number is in the range of 1 to 6. The PNAL command sets or queries the alphanumeric pen number. The pen number is in the range of 1 to 6.

  • Page 197: Print And Plot

    PRINT and PLOT COMMANDS PRSC PALL PTRC PCUR The PRSC command will print the screen display to a printer attached to the rear panel parallel printer port. This function is the same as the [PRINT] key. The printer type needs to be selected before using the PRSC command.

  • Page 198: Front Panel And Auto Functions

    Remote Programming FRONT PANEL CONTROLS and AUTO FUNCTIONS STRT PAUS REST ATRC (?) {i} ASCL AGAN ARSV APHS AOFF i CMAX The STRT command starts or resumes a scan (and sweep). This func- tion is the same as pressing the [START/CONT] key. STRT is ignored if a scan is already in progress.

  • Page 199: Data Transfer

    DATA TRANSFER COMMANDS OUTP ? i OUTR ? i OAUX? i SNAP ? i,j {,k,l,m,n} The OUTP? i command reads the value of X, Y, R or . The parameter i selects X (i=1), Y (i=2), R (i=3) or floating point numbers with units of Volts or degrees. For example, the response might be "-1.01026".
  • Page 200 Remote Programming SPTS ? i TRCA ? i, j, k TRCB ? i, j, k are also recorded at a single instant. Thus reading X,Y OR R, yields a coherent snapshot of the output signal. If X,Y,R and read, then the values of X,Y are recorded approximately 10µs apart from R, .
  • Page 201 = m x 2 (exp-124) where m is the mantissa and exp is the exponent. The trace data within the SR850 is stored in this format. Data transfers using this format are faster than IEEE floating point format. If data trans- fer speed is important, the TRCL? command should be used.

  • Page 202: Interface

    At fast sample rates, it is important that the receiving interface be able to keep up. If the SR850 finds that the interface is not ready to receive a point, then the fast transfer mode is turned off.
  • Page 203 If the scan is started from the front panel or from the trigger input, then make sure that the SR850 is a talker and the controlling interface a listener BEFORE the scan actu- ally starts.

  • Page 204: Interface Commands

    1.000. The LOCL command sets the local/remote function. If i=0 the SR850 is LOCAL, if i=1 the SR850 will go REMOTE, and if i=2 the SR850 will go into LOCAL LOCKOUT state. The states duplicate the GPIB local/remote states.

  • Page 205: Status Reporting

    STATUS REPORTING COMMANDS The Status Byte definitions follow this section. ESE (?) {i} {,j} ESR? {i} SRE (?) {i} {,j} STB? {i} PSC (?) {i} ERRE (?) {i} {,j} ERRS? {i} LIAE (?) {i} {,j} LIAS? {i} CLS command clears all status registers. The status enable regis- ters are NOT cleared.

  • Page 206: Status Byte Definitions

    Except for SRQ, a bit in the Serial Poll status byte is NOT cleared by polling the status byte. When reading the status byte using a serial poll, the SRQ bit signals that the SR850 is requesting service. The SRQ bit will be set (1) the first time the SR850 is polled following a service request.

  • Page 207: Service Requests

    SERVICE REQUESTS (SRQ) A GPIB service request (SRQ) will be generated whenever a bit in both the Serial Poll Status byte AND Serial Poll Enable register is set. Use SRE to set bits in the Serial Poll Enable register. A service request is only generated when an enabled Serial Poll Status bit becomes set (changes from 0 to 1).

  • Page 208: Lia Status Byte

    Remote Programming LIA STATUS BYTE The LIA Status bits stay set until cleared by reading or by the ERROR STATUS BYTE The Error Status bits stay set until cleared by reading or by the name usage INPUT/RESRV Set when an INPUT or RESRV overload is detected.

  • Page 209: Example Program

    To successfully interface the SR850 to a PC via the GPIB interface, the instrument, interface card, and inter- face drivers must all be configured properly. To configure the SR850, the GPIB address must be set in the SYSTEM SETUP menu. The default GPIB address is 8; use this address unless a conflict occurs with other instruments in your system.
  • Page 210 <devName>\n"); exit(1); else initGpib(SR850); txLia("OUTX1"); /* Set the SR850 to output responses to the GPIB port */ setupLiaForSweep(); /* Setup the SR850 sweep */ printf("\nAcquiring Data\n"); ibtmo(lia,0); /* turn off timeout for lia or set the timeout longer than the scan. The timeout measures the time to transfer the full number of bytes, not the time since the most recent byte is received.*/...
  • Page 211 ("\nReceived %d bytes in LIA binary format\n",ibcnt); printOutLIAResults(); printf ("End of Program"); void printOutBinaryResults(void) /* calculates the first 10 values of R based on the X and Y values takes in FAST mode by the SR850 */ int i; float x,y,r; int *ptr;...
  • Page 212 Remote Programming printf("\n\n"); for (i=0;i<10;i++) printf("%d %e\n",i,rfBuf[i]); void printOutLIAResults(void) /* calculates the first 10 values of R transferred in LIA float format by the SR850 */ int i,mant,exp; int *ptr; float val; printf("\n\n"); ptr =(int *) rfBuf; /* ptr points to integers in rfBuf, not floats! */ for (i=0;i<10;i++) {...
  • Page 213 txLia("DSCL0,.5;DOFF0,.5"); txLia("DHZS0,11"); printf("Scan is Initialized, Press <Enter> to Begin Scan..."); getch(); Remote Programming /* set scale from 0 to 1 V */ /* set 10s/div horizontal */ 6-37...
  • Page 214 Remote Programming 6-38...
  • Page 215 To successfully interface the SR850 to a PC via the GPIB interface, the instrument, interface card, and inter- face drivers must all be configured properly. To configure the SR850, the GPIB address must be set in the SYSTEM SETUP menu. The default GPIB address is 8; use this address unless a conflict occurs with other instruments in your system.
  • Page 216 CALL IBCLR(LIA%) PRINT "The SR850 is reset. Now initialize the scan" PRINT "Press <Enter> to continue." INPUT a Set the SR850 to output responses to the GPIB port WRT$="OUTX1" CALL TXLIA(LIA%, WRT$) Set Internal sweep from 10 to 100 Hz WRT$ = "FMOD1;SLLM10.;SULM100."...
  • Page 217 WRT$ = "FAST2;STRD" CALL TXLIA(LIA%, WRT$) Get FAST mode data. The 100 sec sweep at 64 Hz has 64*100 + 1 points, each point consists of X (2 bytes) and Y (2 bytes) for a total of 4 bytes per sample. 6401*4=25604 bytes. CALL IBRDI(LIA%, RXBUF%(), 25604) PRINT "Scan Finished.";...
  • Page 218 Remote Programming EXPONENT% = RXBUF%(2 * I% + 1) - 124 compute the floating point value R = MANTISSA% * 2! ^ EXPONENT% PRINT "I ="; I%; " R ="; R NEXT I% SUB FINDERR STATIC PRINT "IBFIND ERROR" END SUB SUB TXLIA (LIA%, SND$) CALL IBWRT(LIA%, SND$) wait until the command is finished executing...

  • Page 219: Introduction

    Hardkeys are referenced in braces like [HELP]. <Softkeys> The SR850 has a menu driven user interface. The 6 softkeys to the right of the video display have dif- ferent functions depending upon the information displayed in the menu boxes along the right edge of the screen.

  • Page 220: General Installation

    Use the Setup Screen function in the SYSTEM SETUP menu to position the display in the center of the screen. The fan in the SR850 is required to cool the unit. Do not block the vents in the chassis or the unit may not operate properly.

  • Page 221: Necessary Equipment

    As long as the unit is powered on immediately, this will not affect the test results. The Test Record Make a copy of the SR850 Performance Test Record at the end of this section. Fill in the results of the tests on this record. This record will allow you to determine whether the tests pass or fail and also to preserve a record of the tests.
  • Page 222 Performance Tests...

  • Page 223: Self Tests

    1. Self Tests The self tests check the lock-in hardware. These are functional tests and do not relate to the specifications. These tests should be run before any of the performance tests. Note that the Hardware Test menu offers more tests than are required here. Only those tests which require no additional equipment are discussed in this section.
  • Page 224 Performance Tests...

  • Page 225: Dc Offset

    2. DC Offset This test measures the DC offset of the input. Setup Connect a 50 terminator to the A input. This shorts the input so the lock-in's own DC offset will be measured. Procedure 1) {PRESET} (Turn the lock-in off and on with the [ ] key pressed) 2) Press the keys in the following sequence: [REF/PHASE] <Ref.
  • Page 226 Performance Tests...

  • Page 227: Common Mode Rejection

    3. Common Mode Rejection This test measures the common mode rejection of the lock-in. Setup We will use the internal oscillator sine output to provide the signal. Connect the Sine Out to both the A and B inputs of the lock-in. Use equal length cables from A and B to a BNC TEE.
  • Page 228 Performance Tests 7-10...

  • Page 229: Amplitude Accuracy And Flatness

    4. Amplitude Accuracy and Flatness This test measures the amplitude accuracy and frequency response. Setup We will use the frequency synthesizer to provide an accurate frequency and the AC calibrator to provide a sine wave with an exact amplitude. Connect the output of the frequency synthesizer to the phase lock input of the calibrator. Connect the output of the AC calibrator to the A input of the lock-in.
  • Page 230 Performance Tests a) Set the AC calibrator to the amplitude shown in the table. b) Press <Sensitivity> Use the knob to select the sensitivity from the table. c) Wait for the R reading to stabilize. Record the value of R for each sensitivity. 4) Frequency response is checked at frequencies above 1 kHz.

  • Page 231: Amplitude Linearity

    5. Amplitude Linearity This test measures the amplitude linearity. This tests how accurately the lock-in measures a signal smaller than full scale. Setup We will use the frequency synthesizer to provide an accurate frequency and the AC calibrator to provide a sine wave with an exact amplitude.
  • Page 232 Performance Tests 3) For each of the amplitudes listed below, perform steps 3a through 3c. AC Calibrator Amplitudes 1.0000 Vrms 100.00 mVrms 10.000 mVrms 4.000 mVrms a) Set the AC calibrator to the amplitude in the table. b) Press the keys in the following sequence: <Expand>...

  • Page 233: Frequency Accuracy

    6. Frequency Accuracy This test measures the frequency accuracy of the lock-in. This tests the accuracy of the frequency counter inside the unit. The counter is used only in external reference mode. The internal oscillator frequency is set by a crystal and has 25 ppm frequency accuracy. Setup We will use the frequency synthesizer to provide the reference signal.
  • Page 234 Performance Tests 7-16...

  • Page 235: Phase Accuracy

    7. Phase Accuracy This test measures the phase accuracy of the lock-in. Due to the design of the lock-in, the phase accuracy can be determined by measuring the phase of the internal oscillator Sine Out. Setup Connect the Sine Out to the A input of the lock-in using a 1 meter BNC cable. Do not use any termination. Procedure 1) {PRESET} (Turn the lock-in off and on with the [ ] key pressed) 2) Press the keys in the following sequence:...
  • Page 236 Performance Tests 7-18...

  • Page 237: Sine Output Amplitude

    8. Sine Output Amplitude Accuracy and Flatness This test measures the amplitude accuracy and frequency response of the internal oscillator Sine Out. Setup We will use the lock-in to measure the Sine Out. Connect the Sine Out to the A input of the lock-in. Procedure 1) {PRESET} (Turn the lock-in off and on with the [ ] key pressed) 2) Press the keys in the following sequence:...
  • Page 238 Performance Tests c) Press [GAIN/TC] <Sensitivity> Use the knob to select 1 V. [REF/PHASE] <Sine Output> [1] [ENTER] d) Press <Ref. Frequency> Enter the frequency from the table. e) Wait for the R reading to stabilize. Record the value of R. f) Repeat steps 4d and 4e for all of the frequencies listed.

  • Page 239: Dc Outputs And Inputs

    9. DC Outputs and Inputs This test measures the DC accuracy of the DC outputs and inputs of the lock-in. Setup We will use the digital voltmeter (DVM) to measure the DC outputs of the lock-in. Then we will use one of the outputs to generate a voltage to measure on the DC inputs.
  • Page 240 Performance Tests c) For each output voltage in the table below, repeat steps 5d and 5e. Output Voltages -10.000 -5.000 0.000 5.000 10.000 d) Press <Voltage> Enter the voltage from the table. e) Record the DVM reading. 6) Press [DISPLAY/SCALE] <Monitor>...

  • Page 241: 10. Input Noise

    10. Input Noise This test measures the lock-in input noise. Setup Connect a 50 termination to the A input. This grounds the input so the lock-in's own noise is measured. Procedure 1) {PRESET} (Turn the lock-in off and on with the [ ] key pressed) 2) Press the keys in the following sequence: [GAIN/TC] <Sensitivity>...
  • Page 242 Performance Tests 7-24...

  • Page 243: Performance Test Record

    SR850 Performance Test Record Serial Number Firmware Revision Equipment Used 1. Self Tests Test Power On Tests Keypad Knob Main Memory Video Memory 2. DC Offset Input Coupling 3. Common Mode Rejection Frequency 100 Hz 4. Amplitude Accuracy and Flatness Sensitivity Calibrator Ampl.
  • Page 244 SR850 Performance Test Record 5. Amplitude Linearity Sensitivity 6. Frequency Accuracy Input Frequency 10 kHz 7. Phase Accuracy Frequency 10 Hz 100 Hz 1 kHz 10 kHz 8. Sine Output Amplitude and Flatness Sensitivity 200 mV 50 mV 10 mV Sine Ampl.
  • Page 245 SR850 Performance Test Record 9. DC Outputs and Inputs (continued) Output Output AUX1 Output AUX2 Output AUX3 Output AUX4 Offset Lower Limit -100.00 9.960 V -50.00 4.960 V 0.00 -0.020 V 50.00 -5.040 V 100.00 -10.040 V Voltage Lower Limit -10.000...
  • Page 246 SR850 Performance Test Record 9. DC Outputs and Inputs (continued) Input AUX1 Input AUX2 Input AUX3 Input AUX4 10. Input Noise Frequency 1 kHz Voltage Lower Limit -10.000 -10.040 V -5.000 -5.040 V 0.000 -0.020 V 5.000 4.960 V 10.000 9.960 V...

  • Page 247: Circuit Boards

    Disk Drive CIRCUIT BOARDS The SR850 has four main printed circuit board assemblies. The four boards shown above contain most of the active circuitry of the unit. The CRT and video driver circuits are mounted inside the CRT shield assembly.
  • Page 248 SR850 Service...
  • Page 249 7. Connect a 50 termination to the A input. This shorts the input so the lock-in's own DC offset will be measured. Press [GAIN/TC] <Filter dB/oct> twice to select 24 dB/oct <Sensitivity> Rotate the knob to select 100 mV full scale SR850 Service Analog Board Board 2xLine Notch Depth Line Notch Depth 2xLine Notch Freq...
  • Page 250 SR850 Service If the R reading (top display) is less than 1 mV, then proceed to the next step. If the reading is greater than 1 mV, adjust the Voltage Input Offset pot until R is less than 1 mV.
  • Page 251 15. Turn the unit OFF. Replace the magnetic shield at the front of the Analog board and replace the card cage cover. Tighten the two cover screws. Replace the top lid. The lid slides forward and down to engage the clip at the center front. Replace the four black screws to secure the lid. SR850 Service...

  • Page 252: Adjusting Notch Filters

    SR850 Service Adjusting the Notch Filters 1. The Notch filter frequency and depth adjustments must be done together. This procedure requires a BNC cables. A small slotted screwdriver is also required to adjust the potentiometers. 2. Turn the unit ON while holding the [<-] key down. This resets the unit. Let it warm up for at least an hour.
  • Page 253 12. This completes the notch filter adjustment procedure. 13. Turn the unit OFF. Replace the top lid. The lid slides forward and down to engage the clip at the center front. Replace the four black screws to secure the lid. SR850 Service (bottom display) is (bottom display)
  • Page 254 SR850 Service...

  • Page 255: Circuit Description

    Refer any service problems to the factory. CIRCUIT BOARDS The SR850 has four main printed circuit boards. The four boards shown contain most of the active circuitry of the unit. The CRT and video driver board are mounted inside the CRT shield assem- bly.
  • Page 256 Circuit Description...

  • Page 257: Cpu Board

    CPU BOARD The CPU board contains the microprocessor system. All display, front panel, disk, and comput- er interfaces are on this board. MICROPROCESSOR SYSTEM The microprocessor, U101, is an 80C186 micro- controller which integrates a fast 16 bit processor, counter-timers, interrupt controller, DMA controller, and I/O decoding into a single component.

  • Page 258: Circuit Description

    Circuit Description SPEAKER The speaker is driven by a timer on the 80C186. The timer outputs a square wave which is enabled by U602B and drives the speaker through Q705. CLOCK/CALENDAR U702 is an MC146818 real time clock chip which keeps track of time and date.

  • Page 259: Power Supply Board

    POWER SUPPLY BOARD CAUTION: Dangerous voltages are present on this circuit board whenever the instrument is attached to an AC power source and the front panel power switch is "on". Always disconnect the power cord and wait at least one minute before opening the unit. Check the LED at the front edge of the power supply board.
  • Page 260 Circuit Description...

  • Page 261: Dsp Logic Board

    24 dB/oct filtering on both X and Y as well as pro- viding a synthesized analog sine output. DSP PROCESSOR The SR850 utilizes a Motorola 24-bit DSP56001 digital signal processor (U501). The DSP is config- ured without external memory. The lock-in algo- rithms run entirely within the internal program and data memory of the DSP itself.

  • Page 262: Dac Outputs

    Circuit Description transmit port each cycle. The transmit port oper- ates at twice the frequency of the receive port. The DSP writes to the other channel of each DAC via a pair of parallel-to-serial registers (U504 and U505). DAC OUTPUTS Three of the DAC output channels provide Sine Out, X and Y.

  • Page 263: Analog Input Board

    The design of the front end input amplifier in the SR850 was driven by an effort to provide optimum performance in the following areas: input voltage noise, input current noise, input capacitance, harmonic distortion, and common mode rejection (CMR).
  • Page 264 Circuit Description a rate of 256 kHz. One channel is dedicated to the input signal. The other channel reads one of the Aux A/D inputs. The Aux inputs are multiplexed so that each input is read every four cycles. The two digital output streams are buffered by U406 and sent to the DSP board.

  • Page 265: Parts List

    Power Supply Board Parts List Ref. SRS Part No. Value 5-00124-526 5600U 5-00124-526 5600U 5-00228-526 15000U 5-00228-526 15000U 5-00230-550 47000U 5-00229-521 15000U 5-00023-529 5-00127-524 2.2U 5-00038-509 C 10 5-00027-503 .01U C 11 5-00002-501 100P C 12 5-00027-503 .01U C 13 5-00002-501 100P C 16...
  • Page 266 Ref. SRS Part No. Value D 30 3-00479-301 MUR410 D 31 3-00479-301 MUR410 D 32 3-00479-301 MUR410 D 33 3-00479-301 MUR410 D 34 3-00391-301 MBR360 D 35 3-00391-301 MBR360 D 36 3-00391-301 MBR360 D 37 3-00391-301 MBR360 D 38 3-00001-301 1N4001 3-00011-303 1-00039-116...

  • Page 267: Dsp Logic Board

    Ref. SRS Part No. Value R 37 4-00522-407 R 38 4-00517-407 3.57K R 39 4-00522-407 R 40 4-00517-407 3.57K 1-00152-116 11 PIN, WHITE 3-00039-340 74HC14 3-00319-340 AD586JN 3-00088-340 LF353 3-00088-340 LF353 3-00119-329 7905 3-00346-329 7812 3-00346-329 7812 3-00330-329 7912 3-00149-329 LM317T U 10 3-00141-329...
  • Page 268 Ref. SRS Part No. Value C 153 5-00023-529 C 154 5-00023-529 C 155 5-00023-529 C 156 5-00023-529 C 157 5-00023-529 C 171 5-00002-501 100P C 173 5-00002-501 100P C 180 5-00038-509 C 181 5-00038-509 C 182 5-00100-517 2.2U C 183 5-00100-517 2.2U C 202...
  • Page 269 Ref. SRS Part No. Value C 384 5-00100-517 2.2U C 385 5-00100-517 2.2U C 386 5-00100-517 2.2U C 387 5-00100-517 2.2U C 388 5-00100-517 2.2U C 389 5-00038-509 C 390 5-00038-509 C 401 5-00023-529 C 402 5-00023-529 C 403 5-00023-529 C 404 5-00023-529 C 406...
  • Page 270 Ref. SRS Part No. Value C 655 5-00225-548 .1U AXIAL C 656 5-00225-548 .1U AXIAL C 657 5-00225-548 .1U AXIAL C 658 5-00225-548 .1U AXIAL C 659 5-00225-548 .1U AXIAL C 660 5-00225-548 .1U AXIAL C 661 5-00225-548 .1U AXIAL C 662 5-00225-548 .1U AXIAL...
  • Page 271 Ref. SRS Part No. Value N 603 4-00463-421 82X4 N 604 4-00463-421 82X4 7-00356-701 L/I DIGITAL Q 101 3-00021-325 2N3904 Q 102 3-00022-325 2N3906 Q 201 3-00021-325 2N3904 R 102 4-00022-401 1.0M R 103 4-00130-407 1.00K R 114 4-00056-401 R 115 4-00142-407 100K R 116...
  • Page 272 Ref. SRS Part No. Value R 213 4-00317-407 R 214 4-00652-407 1.58K R 215 4-00409-408 1.210K R 216 4-00409-408 1.210K R 217 4-00523-407 R 221 4-00130-407 1.00K R 222 4-00188-407 4.99K R 226 4-00782-448 54.9 R 227 4-00193-407 R 228 4-00704-407 54.9 R 231...
  • Page 273 Ref. SRS Part No. Value RX623 4-00053-401 T 201 6-00137-601 15MH TP101 1-00143-101 TEST JACK TP102 1-00143-101 TEST JACK TP103 1-00143-101 TEST JACK TP104 1-00143-101 TEST JACK TP105 1-00143-101 TEST JACK TP106 1-00143-101 TEST JACK TP107 1-00143-101 TEST JACK TP108 1-00143-101 TEST JACK TP201...

  • Page 274: Analog Input Board

    3-00265-340 74HC595 U 503 3-00265-340 74HC595 U 504 3-00488-340 74HC597 U 505 3-00488-340 74HC597 U 601 3-00495-343 SR850 U601 U 602 3-00496-343 SR850 U602 U 603 3-00497-343 SR850 U603 U 604 3-00498-343 SR850 U604 U 606 3-00499-343 SR850 U606 U 608...
  • Page 275 Ref. SRS Part No. Value C 153 5-00023-529 C 180 5-00038-509 C 181 5-00038-509 C 182 5-00100-517 2.2U C 183 5-00100-517 2.2U C 201 5-00060-512 1.0U C 202 5-00060-512 1.0U C 221 5-00060-512 1.0U C 222 5-00060-512 1.0U C 225 5-00007-501 220P C 261...
  • Page 276 Ref. SRS Part No. Value C 463 5-00023-529 C 480 5-00098-517 C 481 5-00098-517 C 482 5-00098-517 C 483 5-00098-517 C 511 5-00100-517 2.2U C 512 5-00100-517 2.2U C 513 5-00100-517 2.2U C 514 5-00100-517 2.2U C 515 5-00098-517 C 516 5-00023-529 C 517 5-00023-529...
  • Page 277 Ref. SRS Part No. Value P 101 4-00015-445 100K P 102 4-00354-445 P 103 4-00015-445 100K P 201 4-00759-445 P 202 4-00760-445 P 221 4-00730-445 P 222 4-00760-445 7-00355-701 L/I ANALOG R 101 4-00021-401 1.0K R 102 4-00131-407 1.00M R 103 4-00306-407 100M R 104...
  • Page 278 Ref. SRS Part No. Value R 225 4-00321-407 1.74K R 226 4-00158-407 2.00K R 227 4-00158-407 2.00K R 228 4-00158-407 2.00K R 241 4-00380-407 6.34K R 242 4-00556-407 2.94K R 244 4-00380-407 6.34K R 245 4-00556-407 2.94K R 246 4-00380-407 6.34K R 247 4-00556-407...
  • Page 279 Ref. SRS Part No. Value R 371 4-00763-407 14.0K R 372 4-00700-407 1.62K R 373 4-00763-407 14.0K R 374 4-00158-407 2.00K R 375 4-00158-407 2.00K R 379 4-00303-407 7.87K R 381 4-00156-407 16.2K R 382 4-00202-407 R 383 4-00595-407 13.3K R 384 4-00158-407 2.00K...
  • Page 280 Ref. SRS Part No. Value TP102 1-00143-101 TEST JACK TP103 1-00143-101 TEST JACK TP104 1-00143-101 TEST JACK TP201 1-00143-101 TEST JACK TP301 1-00143-101 TEST JACK TP302 1-00143-101 TEST JACK TP303 1-00143-101 TEST JACK TP405 1-00143-101 TEST JACK TP406 1-00143-101 TEST JACK TP407 1-00143-101 TEST JACK...

  • Page 281: Cpu Board

    Ref. SRS Part No. Value U 381 3-00130-340 5532A U 386 3-00423-340 5534 U 391 3-00088-340 LF353 U 401 3-00087-340 LF347 U 402 3-00402-340 74HC4052 U 403 3-00423-340 5534 U 406 3-00155-340 74HC04 U 407 3-00392-340 PCM1750P U 480 3-00116-325 78L05 U 481 3-00122-325...
  • Page 282 Ref. SRS Part No. Value C 902 5-00003-501 C 903 5-00061-513 .001U C 904 5-00223-513 .027U C 905 5-00068-513 .047U C 906 5-00061-513 .001U C 907 5-00012-501 330P C 908 5-00012-501 330P C 909 5-00178-501 C 910 5-00178-501 C 1001 5-00225-548 .1U AXIAL C 1002...
  • Page 283 Ref. SRS Part No. Value C 1041 5-00225-548 .1U AXIAL C 1042 5-00100-517 2.2U C 1043 5-00225-548 .1U AXIAL C 1044 5-00225-548 .1U AXIAL CU901 5-00114-501 200P D 100 3-00391-301 MBR360 D 401 3-00004-301 1N4148 D 601 3-00004-301 1N4148 D 602 3-00004-301 1N4148 D 603...
  • Page 284 Ref. SRS Part No. Value Q 703 3-00021-325 2N3904 Q 705 3-00022-325 2N3906 Q 810 3-00022-325 2N3906 Q 811 3-00021-325 2N3904 R 401 4-00034-401 R 402 4-00079-401 4.7K R 502 4-00034-401 R 601 4-00034-401 R 602 4-00034-401 R 701 4-00088-401 R 702 4-00021-401 1.0K...
  • Page 285 Ref. SRS Part No. Value U 207 3-00343-340 74ALS32 U 208 3-00344-340 74ALS08 U 401 3-00551-341 128KX8-70 U 402 3-00551-341 128KX8-70 U 403 3-00551-341 128KX8-70 U 404 3-00551-341 128KX8-70 U 501 3-00342-340 74ALS138 U 502 3-00342-340 74ALS138 U 503 3-00342-340 74ALS138 U 504 3-00049-340...

  • Page 286: Chassis Assembly

    Ref. SRS Part No. Value U 908 3-00040-340 74HC157 X 101 6-00068-620 24.000 MHZ X 801 6-00069-620 13.5168 MHZ X 901 6-00068-620 24.000 MHZ X 902 6-00037-620 3.6864 MHZ 0-00126-053 3-1/2" #24 0-00479-055 1.5"X#30 ORA 1-00136-171 26 COND 1-00137-165 25 PIN IDC Chassis Assembly Parts List Ref.
  • Page 287 Ref. SRS Part No. Value 0-00259-021 4-40X1/2"PP 0-00310-010 HEX 3/8-32 0-00330-050 5-1/2" #18 0-00331-031 4-40X5/8 F/F 0-00335-000 FAN GUARD 2 0-00336-027 #4X1/4PP-B 0-00337-027 #4X3/8PP-B 0-00338-023 2-56X1/4RP 0-00340-016 F0204 0-00343-027 #4X1/4PF-B 0-00350-053 2-1/4" #24 0-00368-053 21" #24 0-00369-053 21" #24 0-00372-000 BE CU / FFT 0-00377-004 SR760/830/780...
  • Page 288 SR850-5 7-00431-720 SR770-21/22 7-00432-720 SR770-23 7-00433-720 SR770-24 7-00434-721 SR770-25 7-00435-720 SR770-26 7-00436-701 FFT/DSP LI 7-00437-701 FFT/DSP LI 7-00438-701 SR850 RP 7-00458-720 SR850-6 7-00459-720 SR850-7 7-00473-720 SR770-27/28/29 7-00520-709 SR850-12 7-00718-720 SR770-33 8-00034-850 FLOPPY 8-00040-840 7" Z-AXIS Description Connector, Male, Right Angle...

  • Page 289: Miscellaneous

    Ref. SRS Part No. Value 9-00267-917 GENERIC Miscellaneous Parts List Ref. SRS Part No. Value U 301 3-00450-342 27C010-120 U 302 3-00450-342 27C010-120 U 303 3-00450-342 27C010-120 U 304 3-00450-342 27C010-120 0-00089-033 4" 0-00159-000 FAN GUARD 0-00179-000 RIGHT FOOT 0-00180-000 LEFT FOOT 0-00185-021 6-32X3/8PP...
  • Page 290 Parts List NOTICE: Schematics may not show current part numbers or values. Refer to parts list for current part numbers or values. 9-36...

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