KEI 194A Operating & Programming 电路图.pdf

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1、USING THIS GUIDE This reference and programming guide contains condensed specifications, a summary of front panel operating controls. and IEEE-488 programming commands and examples for the Models 194A. 1941, and 1944A. It is intended to pro- vide a quick reference to the many available features of y

2、our instrument as well as the many programming commands available to control the instrument over the IEEE-488 bus. Because of the limited amount space available in this guide. many details abourinstrument operation will not be found here. Refer to the Model 194A Instwction Manual for aspects of inst

3、rument operation not covered in this guide. This guide describes the following aspects of the Model 194A: ? Front panel operation including XY mode. ? A description of mathematical functions. * Input and output signal connections. ? IEEE-488 programming information, including commands, data and stat

4、us formats. and exampkprograms for typical COntrOllers. 01989, Keithley Instruments. Inc. 28775 Aurora Road Cleveland, Ohio 44139 Document Number: 194A-900-01 Rev. A 1 RadioFans.CN 收音机爱 好者资料库 CONTENTS CONDENSED SPECIFICATIONS . . . 4 ENGlNEERlNG “NITS CONVERSION . . . ._5 SAFElYPRECAUTIONS. 6 FRONT

5、PANEL FEATURES AND OPERATlON. . 7 Display Annunciators Genera, Display Messages Shift Functions Mathematical Functions Ratio and Difference Modes Range Data Entry Programmable Parameters Rate and Samples Programming Recalling Data Trigger Channel Selection Input Coupling Zero Filter FRONT PANEL PROG

6、RAMS., _ _ 25 SetUP- status Reset XY Mode INPUT AND OUTPUT CONNECTIONS . 3, A/D Module InpuffOutput Connections Analog Output Connections Enernal Clock IEEE-466 PROGRAMMING. _, 36 Device-dependent Commands TRANSLATOR MODE. _. _ ._ _ _ 56 CONTROLLER PROGRAMS t t _ _ _ 56 IBM XT or PC (with CEC Interf

7、ace1 Hewlett-Pock 100kHz et 16.bit resolution. MATH FUNCTIONS: Average, Peak, Peak-to-Peak, TRMS, Standard Deviation, Integral, Waveform. FRONT PANEL PROGRAMS: IEEE-466 Address, Self Test, Digital Calibration, Calibration Storage, X Output Full Scale, Y Output Full Scale, Z Output Blanking Level, DI

8、SPLAY Fourteen digit alphanumeric LED display. RANGING: Manual or autoranging. CONNECTORS: All I/O connectors are BNC except Real Trme Output IDS-261 and IEEE-466 connectors. 4 RadioFans.CN 收音机爱 好者资料库 ENGINEERING UNITS AND SCIENTIFIC NOTATION CONVERSION Prefix Engineering Symbol Scientific Notation

9、I pico- “anO- micro- milli- kilo- mega- giga- tera- peta- 5 SAFETY PRECAUTIONS The following safety precautions should be observed before using the Model 194A: 1. Before operation. ground the instrument through-a pro- perly earth grounded power receptacle 2. Do not exceed 30” rms between input low a

10、nd earth ground. 3. Do not exceed the maximum allowable input 8s defined in the condensed specifications section of this guide 4. Before servicing. disconnect the Model lg4A from the power line and all other equipment. 5. Do not touch any terminals while the instrument is turn- ed on or connected to

11、 any other equipment or sources. FRONT PANEL FEATURES AND OPERATION DISPLAY DESCRIPTION The Model lg4A display consists of fourteen 14.segment LED units which display both instrument readings as well as many messages to augment the variow operational modes. The basic display format for readings incl

12、udes the voltage value, units ImV or VI. mathematical function (for example AVG for average) and channel number (1 or 2). Channel 2 is available only for those units equipped with a Model lg44A AID module in the CARD 2 location. The display can be operated singlechannel or dualchannel, as selected w

13、ith the CHANNEL button. The selected than- nel also dictates which channel is affected by pressing other buttons. Most other modes cannot be changed when the display is in the dual-channel mode DISPLAY EXAMPLES Typical examples for the display modes include: Channel 1 Average Reading: -1.2500 V AVG

14、1. Channel 2 TRMS Reading: 0.3450 mV RMS 2. Dual Channel Reading: -1.2500 0.3450 ANNUNCIATORS Front panel annunciators indicate when a number of front panel modes are selected as described below: IEEE-488 STATUS: The TALK, LISTEN, and REMOTE in- dicators show when the instrument has been placed in t

15、hose respective modes via programming commands sent wer the IEEE-488 bus. These indicators are not operational during front panel operation. ZERO: Indicates when a baseline measurement is being sub- tracted from subsequent measurements. FILTER: Shows when either the 5OkHz or 5OOkHr analog filters ar

16、e enabled. SGUCONT: Indicates when the instrument is in the single or ccmtinuou* trigger. SLOPE: Shows whether the instrument will be triggered on the rising or falling edge of an input signal waveform. CPLG: Indicates BC or dc input coupling. Ground coupling is selected when both indicators are off

17、. AUTO: Shows when the instrument is in the autorange mode. SHW Shows when the shift mode has been enabled by pressing the shift key. Shifted modes are marked below the respective control buttons. RECALL: Indicates when the recall mode is in effect. This mode allows access to individual samples in t

18、he measure- ment buffer. 8 GENERAL DISPLAY MESSAGES Display messages that may occur during general front panel cpererlcn are summarimzi below. The unit also has a number of specific messages associated with the various operating modes, as described in the instruction manual. MESSAGE DESCRIPTION OFLO

19、 Overrange input applied for at least one sample. SHIFTLESS KEY Shift function invoked for key not having one. NMSR TOO SMALL Too small a value keyed in dur- ing data entry. iwmi7 mo LARGE Too big a value keyed in during data entry. SHIFT FUNCTIONS DESCRIPTION Many of the front panel keys have a sec

20、ondary function which is placed intoaffect by pressing theSHIFT key before pressing that particular button. Each shifted function is listed below the key in question. For example, pressing SHIFT ZERO VAL allows a baseline value to be keyed in from the front panel. While the shift function is enabled

21、. the associated indicator will be on. Pressing a key which does not have ashifted function will result in the following display message: SHIFTLESS KEY MATHEMATICAL FUNCTIONS DESCRIPTION The Model 1g4A has a number of mathematical functions that can be applied to the measurement. If the instrument 1

22、0 is in a continuous trigger mode. a single math function, Once selected, can be applied to successive measurements. In a single trigger mode, a variety of different math functions can be applied to a single measurement. Each mathematical function can be enabled by pressing SHIFT followed by the cor

23、responding key. OPERATION WAVEFORM: Displays the individual sample occurring at the trigger point, or thesample as close as possible to the trigger point. Example: 1.2345 V DC 1. PK TO PK: Displays the peak-to-peak value of the measure- ment, which is calculated by subtracting the most negative samp

24、le from the most positive samples Eample: 2.3410 V P-P 1. STD DEW Displays the standard deviation of the measure- ment, which shows how far the samples deviate from the average of the measurement. Example: -12.341 V STD 1. INTEGRAL Displays the integral of the measurement, which is the area under a

25、curve bounded by the measurement amplitude and the measurement duration. Example: 800.23 VS 2. AVG: Shows the average of the measurement, which is calculated by dividing the sum of all the samples bv the number of sample. Example: -16.225 V AVG 1. TRMS: Displays the true rms value of the measrment.

26、Ex- ample: 31.800 V RMS 1. PEAK: Shows the most positive or mrxt negative sample in the measurement. Example: 1.1220 V PK+ 1. Press repeatedly to alternate between positive and negative peak. RATIO AND DIFFERENCE MODES ( 0 00 00000 DESCRIPTION The ratio and difference modes allow you to divide the c

27、hat- nel 1 reading by the channel 2 reading or to subtract the channel 2 reading fmm the channel 1 reading. In order to use either of these modes, the optional Model 1944A A/D Module must be installed in the CARD 2 location. If there is no second channel installed, pressing either CHl-CHZ or CHl+CHZ

28、 module installed will result in the following message: NOAiDINCH2 OPERATION CHlrCH2 IRatio): To display the ratio between the two channels, press SHIFT CHltCH2. The instrument will then display the ratio as in this example: 1.2367 V l/2. 12 CHI-CH2 (Differencel: To display the difference between th

29、e two channekpress SHIFT CHl-CHZ. The instrument will then display the difference between the two channels. as in this examole: 2.4000 V 1-2. RANGE DESCRIPTION The ranging controls give you control over sensitivity of the measurement The range may be selected either on an automatic or manual basis.

30、When using manual ranging, the lowest rangepossible without overranging the instru- ment should be used to maximize accuracy and resolution. 13 OPERATION AUTO: The AUTO button toggles the instrument between auto and manual ranging. The AUTO indicator will be on when in autoranging. Uprange: Pressing

31、 uprange moves the instrument to the next higher range until the highest (2OOVl range is reach- ed, Uprange also cancels autorange if that mode is presently enabled. Uprange is also used with various other functions such as data entry and recall. Downrange: This key moves the instrument to the next

32、lower range when pressed until the lowest I32OmVl range is reached. Downrange also cancels autorange if enabled. and it is used with various other functions such as data en- try and recall. 14 The Data Entry keys allow the entry of numeric data into those functions requiring values. These keys are u

33、sed to program values for rate. samples, trigger kvel. zero, and trig get delay. During the entry process, the keyed in digits will appear on the display. OPERATION Numeric Keys (O-9. +/-,. I: These keys enter actual numeric data including decimal point and sign into the display after the appropriat

34、e function has been entered. ENTER: Pressing ENTER actually enters keyed in data into the function in question. CANCEL: May be used to cancel keyed in data and return to the previous value. 15 Units Keys (MHz, kHz, Hzl: Determines the type of units to be keyed in. Voltage or time or frequency units

35、are automatically chosen by the selected function. Pressing a units key automatically enters the displayed data. FRED/TIME: This key toggles the instrument between time tec, msec, sl and frequency (MHz, kHz, Hz1 units. For ex- ample, sampling rate may be entered either as time inter- val or sampling

36、 frequency units. Cursor Control: During the data entry process. the digit af- fected by pressing a numeric keey will be indicated by a flashing segment or digit. This cursor can be moved left or right with the downrange or uprange buttons. respectively. PROGRAMMABLE PARAMETERS Perameten to be progr

37、ammed with the Date Entry keys are summarized below, along with limits and resolution of each parameter. 16 FUllCtkJ RATE SAMPLES DELAY LEVEL ZERO “AL x output Full Scale* Y Output* Full Scale Limits Time Irsec-lsec Frequency lHz-1MHz No: l-65.535* lime: Opsec-65,534sec NO Samples: -65,536 to 10 lim

38、e: -65,536 to 10sec *20CW *2ocw l-1OV nominal l-1OV nominal bsohJtion 0.1 rrjec HZ Samples 0.1 *ec Samples RATE AND SAMPLES PROGRAMMING DESCRIPTION A measurement is made up of a number of samples taken at specific intervals. The number of samples in that measurement, as well as how fast those sample

39、s are taken can be programmed with the SAMPLES and RATE keys. These parameters are entered with the Data Entry keeys OCB the mode in question is enabled. RATE: Sampling rate may be entered in time (Isec -lpecl or frequency (IHI-1MHr). To program sampling rate, press the RATE key and press the numeri

40、c buttons in the desired sequence. Press the FRECUTIME key, as required, to enter time or frequency units. SAMPLES: The size of the measurement may be entered as the number of samples 11-65.536) or measurement time duration il#ec-65,536secl. To program the number of samples, press SAMPLES and then k

41、ey in the desired value withy the numeric keys. Use FREQiTlME to select sampling interval or number of samples, as desired. RECALLING DATA DESCRIPTION Recall allcw you tc display individual samples within the measurement. This mode is entered by using the RECALL button. Once in the recall mode, indi

42、vidual samples may be accessed on a sequenr,al or random basics. OPERATION To enter recall, simply press the RECALL button. While in this mode, the RECALL indicator button will be on. To ac- cess individual samples, either use the uprange or downrange keys to access individual samples, or key in a s

43、pecific sample number and press the ENTER key. TRIGGER DESCRIPTION The Model 194A may be triggered in a variety of different ways: with the TRIGGER button. with an input pulse ap- plied to the TRIGGER IN jack, from the other channel, or from the input signal. When triggering from the input signal, t

44、he slope and trigger level can be programmed. 19 OPERATION SOURCE: To select the trigger scum?, press SOURCE repeatedly until the desired mode is displayed: front panel (TRIGGER), input signal, external. or other channel. Press CHANNEL to save the selected source. SGUCONI A measurement sequence can

45、beperformed on a continuous or single basis. In a continuous mode, the in- strument repeatedly arms the A/D for the next trigger measurement without requiring additional triggers. In the single mode, B separate arm stimulus is required for each measurement. SGLICONT toggles the instrument between th

46、ese two modes, as indicated by the respectiwindicator. TRIGGER: When selected with the SOURCE key,pressing this keey will initiate a continuous or single measurement, depending on the selected mode SLOPE: Rising or falling edge triggering may be selected with the SLOPE key only when input signal tri

47、ggering is selected. The annunciator next to the key indicates the selected mode LEVEL: When triggering from the input signal, the actual voltage level et which the unit is triggered may be selected with the LEVEL key. Once this mode is entered, the voltage is keyed in with the Data Entry keys. DELA

48、Y Delay selects the number of samples between the trigger and the first sample A positive or negative delay may be selected. Delay may be entered in number of samples or actual time by using the FREOrrlME key. 20 CHANNEL SELECTION DESCRIPTION For dualchannel units, the CHANNEL button allows you to s

49、elect one of three display modes: channel 1, channel 2, or dual-channel display. For the two single-channel modes, the displayed channel also determines which channel will be affected by pressing other keys. In the dual channel mode, most other buttons are inoperative INPUT COUPLING 21 DESCRIPTION The Model 194A has three available forms of input cowl- ing: ac, de, and ground. The selected mode