FLUKE PM6669__omeng0000 电路图.pdf

Universal Frequency Counter PM6669 Operators Manual RadioFans.CN 收音机爱 好者资料库 CONTENTS SAFETY.2 Introduction .2 PRODUCT PRESENTATION .3 General .3 Rear View.3 Front View.4 INSTALLATION .5 Unpacking.5 Voltage-Range Selection .5 Grounding .5 Connecting External Reference.6 Installing Options .6 Calibrating the MTCXO.6 OPERATING INSTRUCTIONS.8 Using the Frequency Counter.8 Battery Unit .20 Error Codes.20 GPIB-INTERFACE OPERATION.21 Introduction .21 What Can I Do Using the Bus?.21 Connecting the Controller.22 Giving the Counter an Address.22 Checking the Communication.22 Two Ways of Programming.23 Syntax .23 Selecting Output Separator.24 How to Select Function .24 Selecting Measuring-Time.24 Selecting Triggering.25 Totalize Start/Stop .25 Free-Run/Triggered.25 Service Request.26 Status Byte.26 Output Mode.27 Bus Learn.30 Programming Data Out .30 What Happens When I Switch to Local?.30 Summary of Bus Commands.31 Programming Examples.32 SPECIFICATIONS .35 Measuring Functions.35 Definitions.36 Input specifications.36 General Information.37 Auxiliary Functions.38 Optional Accessories.38 Ordering Information .40 APPENDIX 1.41 Checking the Sensitivity of Counters .41 INDEX .43 4822 872 20021 5/12-April-1995 CONTENTSPage: 1 PM 6669 - OPERATORS MANUAL RadioFans.CN 收音机爱 好者资料库 SAFETY Introduction Read this page carefully before you install and use the PM 6669 Frequency Counter. This Frequency Counter has been designed and tested in accordance with IEC publication 1010-1, and CSA 22.2 No.231, and has been supplied in a safe condition. The user of this instrument must have the required knowledge of PM 6669. This knowledge can be gained by thoroughly studying this manual. Safety Precautions Use generally-accepted safety procedures, in addition to the safety precautions stated in this manual, to ensure per- sonal safety and safe operation of the Frequency Counter. Caution Set the intermediate frequency as the constant A0. Select FREQ A-A0 and measure the frequency of the local oscillator, and the display will show the received frequency. The frequency on Input-A is multiplied by 60 and dis- played as Revolutions Per Minute. Range:6 RPM to 720 000 000 RPM. When you select SINGLE, the Frequency Counter measures one period, the range is: 100 ns to 200 000 000 s (about 6 years and four months!). When you select 0.2, 1, and 10 s Measuring-time, the Frequency Counter divides the input frequency by 10 and measures the average period for the No. of cy- cles in that time. Range: 8 ns to 1 s. Use SINGLE when the input frequency is low. This shortens the measuring time considerably since one cycle is measured instead of 10. The Frequency Counter counts the total number of pulses fed to Input-A. You start and stop the totalizing with the TOTALIZE START/STOP key (RESET/LO- CAL). If you keep this key depressed for more than one second, the total sum will be reset. Range: 0 to 1*1015 pulses k on the display indicates kilo-pulses (1000) and M in- dicates Mega-pulses(1 000 000). The Measuring-time indicator is switched off in TOT A MAN. OPERATING INSTRUCTIONSPage: 11 PM 6669 - OPERATORS MANUAL CONTROLOPERATING THE CONTROL DISPLAYGPIB-CODE Move function cursor to WIDTH A WIDTH A or PWIDTH A MEAS TIME is operated in the same way as the func-tions control, see page 8. MTIME where is the time in seconds. Range: 10 ms to 10 s. 0 = Single Move the measuring- time cursor to SINGLE MTIME 0 Move the measuring- time cursor to 0.2 s MTIME 0.2 Move the measuring- time cursor to 1 s MTIME 1 Move the measuring - time cursor to 10 s MTIME 10 FUNCTION TRIGGER LEVEL A HOLD DISPLMEASURING TIME 10s1s0.2sSINGLE REF EXT A WIDTH A TOT A PER A RPM A-A0 FREQ A/A0 FREQ B FREQ A FREQ FUNCTION AUTO ms 0. TIME MEAS TIME MEAS TRIGGER LEVEL A HOLD DISPLMEASURING TIME 10s1s0.2sSINGLE REF EXT A WIDTH A TOT A PER A RPM A-A0 FREQ A/A0 FREQ B FREQ A FREQ FUNCTION AUTO kHz TIME MEAS TRIGGER LEVEL A HOLD DISPLMEASURING TIME 10s1s0.2sSINGLE REF EXT A WIDTH A TOT A PER A RPM A-A0 FREQ A/A0 FREQ B FREQ A FREQ FUNCTION AUTO kHz TIME MEAS TRIGGER LEVEL A HOLD DISPLMEASURING TIME 10s1s0.2sSINGLE REF EXT A WIDTH A TOT A PER A RPM A-A0 FREQ A/A0 FREQ B FREQ A FREQ FUNCTION AUTO kHz TIME MEAS TRIGGER LEVEL A HOLD DISPLMEASURING TIME 10s1s0.2sSINGLE REF EXT A WIDTH A TOT A PER A RPM A-A0 FREQ A/A0 FREQ B FREQ A FREQ FUNCTION AUTO kHz Page: 12OPERATING INSTRUCTIONS PM 6669 - OPERATORS MANUAL FUNCTION AND RANGEHINTS AND COMMENTS The counter measures the positive pulse width of the signal on Input-A. Range: 100 ns to 200 000 000 s. If you are interested in the negative pulse width instead; first measure the period and make a note of the result, then measure the pulse width and substract it from the period reading. The set Measuring-time controls the time during which the main gate is opened, allowing pulses to en- ter the counting logic. A longer Measuring-time gives higher resolution readouts with more digits displayed. The time the gate is open is not exactly the preset Measuring-time, because the Frequency Counter syn- chronizes the measurement with the input signal in or- der to measure complete periods. If the period of the input signal is longer than the set Measuring-time, the main gate does not close again until the period is completed. If you wish to do one measurement instead of repetitive measurements, see DISPL HOLD. For PER A and WIDTH exactly one period or one time interval is measured. The minimum result possi- ble is 100 ns. The display time will be 100 ms. When set to SINGLE, FREQ A and, RPM A, the Measuring-time is one cycle of the input signal or 3 ms, whichever is longest. When set to SINGLE and FREQ B, the Measuring-time is 3 ms. The input frequency is limited to 16 MHz for FREQ A, PER A, and RPM A. If external reference is used, the EXT REF indicator will not be switched-on until after the first measurement. A Frequency-A measurement will result in 6-7 digits on the display. A Frequency-A measurement will result in 7-8 digits on the display. A Frequency-A measurement will result in 8-9 digits on the display. OPERATING INSTRUCTIONSPage: 13 PM 6669 - OPERATORS MANUAL CONTROLOPERATING THE CONTROL DISPLAYGPIB-CODE The TRIGGER LEVEL A control is operated in the same way as the functions control, see page 8. One code for each trigger level offset. See below. Move Trigger Level A cursor to AUTO. TLO AUT Move Trigger Level A cursor to TLO POS Move Trigger Level A cursor to TLO SYM Move Trigger Level A cursor to TLO NEG Each depression of the BLANK DIGITS key blanks out one digit starting from the right (Least Sig-nificant Digit). When all digits are blanked out, the next depression removes the blanking. Not bus controllable LEVEL A TRIGGER LEVEL A TRIGGER TRIGGER LEVEL A HOLD DISPLMEASURING TIME 10s1s0.2sSINGLE REF EXT A WIDTH A TOT A PER A RPM A-A0 FREQ A/A0 FREQ B FREQ A FREQ FUNCTION AUTO kHz 0. LEVEL A TRIGGER TRIGGER LEVEL A HOLD DISPLMEASURING TIME 10s1s0.2sSINGLE REF EXT A WIDTH A TOT A PER A RPM A-A0 FREQ A/A0 FREQ B FREQ A FREQ FUNCTION AUTO kHz 0. LEVEL A TRIGGER TRIGGER LEVEL A HOLD DISPLMEASURING TIME 10s1s0.2sSINGLE REF EXT A WIDTH A TOT A PER A RPM A-A0 FREQ A/A0 FREQ B FREQ A FREQ FUNCTION AUTO kHz 0. LEVEL A TRIGGER TRIGGER LEVEL A HOLD DISPLMEASURING TIME 10s1s0.2sSINGLE REF EXT A WIDTH A TOT A PER A RPM A-A0 FREQ A/A0 FREQ B FREQ A FREQ FUNCTION AUTO kHz 0. DIGITS BLANK TRIGGER LEVEL A HOLD DISPLMEASURING TIME 10s1s0.2sSINGLE REF EXT A WIDTH A TOT A PER A RPM A-A0 FREQ A/A0 FREQ B FREQ A FREQ FUNCTION AUTO kHz Page: 14OPERATING INSTRUCTIONS PM 6669 - OPERATORS MANUAL FUNCTION AND RANGEHINTS AND COMMENTS The normal trigger level of the AC-coupled Input-A is 0 V. This is ideal for symmetrical signals like sine- waves, since their average DC component is 50 % of Vp-p. Non-symmetrical signals however, might fail to trigger if the trigger level is 0 V. Therefore there are three trigger level settings available; one for small duty fac- tors, one for symmetrical wave forms and one for large duty factors. It is often possible for the counter to trigger on unsymmetrical signals even though the symmetrical triggering is selected, provided that the sensitivity is high enough. This however, gives poor noise immunity. If you dont know the duty factor of the input signal, select Auto. If that does not work (too low input frequency) do as follows; a)Set the sensitivity to max. b)Select Trigger level . c)Reduce the sensitivity until the gate indicator stops blinking. d)Check if trigger level or makes the gate indicator start blinking again. If it does, leave the trigger level in that position, otherwise return to trigger level . e)Turn the sensitivity down until the gate indicator stops blinking, then up slightly until it starts again. The trigger level is now correct. When set to Auto the counter first tries the trigger level for symmetrical signals. If that does not work, it tries the other settings. Auto does not work if TOT A is selected. Range: Auto works with input frequencies from 100 Hz and up. Use this setting if the duty factor is below 25 %. A positive offset voltage is added to the trigger level. Use this setting if the duty factor is between 25 % and 75 %. The trigger level is 0 V. Use this setting if the duty factor is below 75 %. A negative offset voltage is added to the trigger level. Each digit that is blanked out is removed and re- placed by a -. The numerical value on the display is not rounded off. The blanking is cleared by reset, changing settings or when all digits are blanked and you press the BLANK DIGITS key once more. This function is used to blank the display of irritating, unstable digits. OPERATING INSTRUCTIONSPage: 15 PM 6669 - OPERATORS MANUAL CONTROLOPERATING THE CONTROL DISPLAYGPIB-CODE RESET/LOCAL, a short press is enough for Reset. When the remote indicator is on, a press will cause the counter to switch back to LOCAL, i.e. control from the front panel. TOTALIZE START/STOP, one press starts totalizing, the next press stops. X starts a new measurement. GATE OPEN starts and GATE CLOSE stops Totalize MAN. Switches on or off DISPL HOLD when de- pressed. Not bus con- trollable, but Free-run OFF will give a similar function; See GPIB-bus operation. Connect the signal to INPUT-A via a BNC- cable. Connect the signal to INPUT-B via a BNC- cable. LOCAL RESET START/STOP TOTALIZE A HOLD DISPL A0 STORE TRIGGER LEVEL A HOLD DISPLMEASURING TIME 10s1s0.2sSINGLE REF EXT A WIDTH A TOT A PER A RPM A-A0 FREQ A/A0 FREQ B FREQ A FREQ FUNCTION AUTO kHz u ms GATE 0. M 10Hz-160MHz MAX 350Vp 1M 30pF INPUT A OPTION 70MHz - 1.3GHz MAX 12Vrms 50 INPUT B Page: 16OPERATING INSTRUCTIONS PM 6669 - OPERATORS MANUAL FUNCTION AND RANGEHINTS AND COMMENTS When reset is depressed, the display and counting registers are cleared. When reset is released, a new measurement is started. The Measuring-time-, Func- tionand display hold- settings are not affected. If the TOT A function is selected, the RESET/LOCAL key functions as a START/STOP key. One press starts the counting and the next press stops it. A long depression results in reset. When the counter is controlled from the GPIB-Bus, the LOCAL key can be disabled via the Local Lock out command. Display hold freezes the display, but not until the measurement in process has been finished. A new measurement can always be initiated via the RESET key. Store A0 is used to store the constant used in func- tions FREQ A/A0 and FREQ A-A0. The procedure is described under FUNCTIONS, FREQ A/A0. Use this input for all functions except FREQ B. Range:10 Hz to 160 MHz Impedance:1 M /30 pF Min. pulse duration:4 ns At higher frequencies; use a 50 termination type PM 9585 to avoid interference caused by impedance mis match. The illustration below shows which function block each of the input controls affect. This is the HF-input which must be used when the FREQ-B function is selected. If the Frequency Counter does not include the Input-B option, the BNC- connector is replaced by a plastic plug. Range: 70 to 1300 MHz. Impedance: 50 Sensitivity: 10 mVRMS up to 900 MHz, 15 mVRMS 900-1100 MHz and 40 mVRMS above. Max voltage: 12 VRMS 8 V 0440 Hz1 MHz120 MHz 20 Hz 20 mV 40 mV 60 mV 030 MHz120 MHz160 MHz AC Spec. DC Spec. Typically RMS Max voltage 350 VDC+AC peak Sensitivity Attenuator Sensitivity range switch Counting logic Trigger level offset Input-A Filter Sen