Pendulum CNT-66 User Manual

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CNT-66

Programmable Timer/Counter

Users Manual

4031 600 66001

Rev. 01 (September 2000)

This manual, in whole or in part, may not be copied without permission.

All product name are trademarks of their respective companies.

Table of Contents

EC DECLARATION OF CONFORMITY ........ IV

1 Safety Instructions

Safety ............................. 1-2

Introduction ............................. 1-2

2 Product Presentation

General ................................ 2-2

Rear View .............................. 2-2

Front View .............................. 2-3

3 Installation

Unpacking .............................. 3-2

Voltage Range Selection................... 3-2

Grounding .............................. 3-3

Connecting External Reference ............. 3-3

Installing the Rack Mount Adapter ........... 3-3

4 Operating Instructions

Using the Timer/Counter ................... 4-2

Error Codes............................ 4-14

5 GPIB-interface Operation

Introduction ............................. 5-2

What can I do using the Bus? ............... 5-2

Connecting the Controller .................. 5-3

Giving the Counter an Address .............. 5-3

Checking the Communication ............... 5-3

Two Ways of Programming................. 5-4

Syntax ................................. 5-4

Selecting Output Separator................. 5-5

How to Select Function .................... 5-5

Selecting Measuring-Time.................. 5-6

Selecting Input settings .................... 5-6

Totalize Start/Stop........................ 5-7

Free-Run/Triggered....................... 5-7

Service Request ......................... 5-8

Status Byte ............................. 5-8

Output Mode ........................... 5-10

Bus Learn ............................. 5-12

Programming Data Out ................... 5-12

What Happens When I Switch to Local?...... 5-12

Summary of Bus Commands .............. 5-13

Programming Examples .................. 5-14

6 Performance Check

Performance Check....................... 6-2

7 Calibration and Adjustment

Calibration .............................. 7-2

Timebase References ..................... 7-3

8 Specifications

Measuring Functions...................... 8-2

Input-A and Input-B ....................... 8-3

Input C ................................ 8-3

External Reference Input D .................. 8-3

Auxiliary Functions ....................... 8-4

Definitions .............................. 8-4

General Specifications .................... 8-5

Environmental Data....................... 8-6

Mechanical Data ......................... 8-6

Optional Accessories...................... 8-6

Ordering Information ...................... 8-7

9 Appendix

Checking the Sensitivity of Counters.......... 9-2

10 Service

Sales and Service office................ II

GUARANTEE STATEMENT ................. III

11 Index

Index ............................... II

III

EC DECLARATION OF CONFORMITY

Number: 4031 100 63700A41

The undersigned, representing the following manufacturer:

Manufacturer:

Pendulum Instruments AB Sorterargatan 26, Box 541 SE-162 15 Vällingby, Sweden

Representative: Jan Herwe Function: Quality Manager

herewith declare that the product:

Product Identification:

Product: Timer/Counter Brand: Pendulum Model: CNT-66 Version: All models

is in conformance with the EC Directive 89/336/EEC based on test results using harmonized standards in accordance with Article 10(1) of the directive and the directive LVD-73/23/EEC.

Test report no: Title

Safety release certificate March 18, 1996 SEMKO EMC test report 953210I.3 CEM-Consult AB: CC-EMC/88-1044

Harmonized standards used: Safety: EN 61010-1 (1990) + A1 (1992) + A2 (1995) CAT II EMC: EN 55011 (1991) Group 1, Class B

EN 50082-1 (1992)

Place: Vällingby Date: 2000-05-29

This Conformity is indicated by the symbol , i.e. “Conformité européenne”.

Chapter 1

Safety Instructions

Safety

Introduction

Read this page carefully before you install and use the CNT-66 Timer/Counter.

This Timer/Counter has been designed and tested in accor dance with EN 61010-1 and has been supplied in a safe condition. The user of this instrument must have the re quired knowledge of CNT-66. 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 personal safety and safe operation of the Timer/Counter.

Caution and Warning Statements

You will find specific warning and caution statements, where necessary throughout the manual. Do not carry out repairs or adjustments to the Timer/Counter without reading the Service Manual, which contains the relevant warnings for such activities.

CAUTION: Indicates where incorrect operating pro-

cedures can cause damage to, or destruction of, equipment or other property.

WARNING: Indicates a potential danger that re

quires correct procedures or practices in order to prevent personal injury.

Symbols

Indicates where the protective ground lead is connected inside the instrument. Never un screw or loosen this screw.

Signal Ground symbol. This symbol indicates that the signal ground of the connectors are in ternally connected to the other connectors with the same symbol, and to parts that are easily accessible for the user.

Indicates that the operator should consult the manual.

Such symbols are printed near the input connectors. This symbol on the instrument should encourage the user to use the correct procedure for common instrument ground, and maximum input voltages, as described in the Installation and Specification chapters.

If in Doubt About Safety

Whenever you suspect that it is unsafe to use the instrument, you must make it inoperative, clearly mark it to pre vent its further operation, and inform the Pendulum servic ing department.

E.g.The instrument is likely to be unsafe if it is visibly dam aged.

1-2 Introduction

Chapter 2

Product Presentation

General

The CNT-66 is a compact, high resolution, reciprocal Timer/Counter which performs many functions. A number of options are available i.e. HF-input, GPIB-interface and high stability oscillator.

A rack-mount kit and a carrying case are also available as accessories.

Rear View

S) Rear feet. T) Screws for removing the cover. U) External-reference-input, BNC connector. V) Voltage-range selector. W) Power-inlet socket. X) GPIB interface-connector (optional). Y) GPIB address-selector ( option).

INCLUDED OPTIONS

T U

Figure 2-1 Rear View

IE E E 4 8 8 IN T E R F A C E

OPTION 04 OPTION 07 OPTION 08

OPTION __

OPTION __ OPTION __

TALK O NLY

EXT R EF INPUT

10M H z 0.5-15V rm s

ADDRESS

8421

OFF

VOLTAGE

SELECTOR

SUPPO RTED FUNCTIONS: S H 1 , A H 1 T 5 , L 4 S R 1 , R L 1 DC1, DT1 E2

LR 39484

T H E R M A L F U S E IN

M AIN S TRAN SFORM ER

2-2 General

Product Presentation

MEASU RING TIM E

SINGLE

0.2s 1s

FRE Q

STANDBY

TO TALIZE A

START/STOP

10s

P E R IO D T IM ERATIO

AA-B

M EAS

TIM E

A/B

FUN CTIO N

RESET LO CA L

DISPLAY

HOLD

EXT

COMMON

B via A

REF

TO T A

T O T A T O T A V O L T A

BMAN

DISPL HOLD

AUTO LEV EL

COM MON

B via A

PON

LEV EL

MAX-MIN

50 W

M AX 12Vrm s

READ

70M Hz - 1.3G Hz

ATTx1

x10

SET A SET B

35pF

DC - 160MHz

M AX 30Vrm s

DC DC

AC x10

DC TRIGGER LEVEL

AC SENSITIVITY

READ

AUTO

LEVEL

M AX 30Vrm s

ATTx1

35pF

ABCD

Figure 2-2 Front View

Front View

A) Power switch. B) Reset button, doubles as Local button if the

Timer/Counter is equipped with an GPIB interface. Starts and stops counting if the TOT A MAN func

tion is selected. C) Measuring-time selector-button. * D) Function-selector button. * E) Display-hold button. Freezes the display. F) COM B via A button connects the signal on input A

to input B. The Input-A attenuator and AC/DC

switch affect both inputs. G) Input-C BNC-connector (optional). H) Input-A BNC-connector. I) Set value button, depress to set sensitivity (AC) or

trigger level (DC).

J) Auto level, starts automatic trigger level setting. If

‘Set Value’ is selected, this button is used to in

crease the value.

K) Read level, displays trigger levels. If ‘Set Value’ is

depressed, this button is used to decrease the

value. L) Input-B BNC-connector. M) Trigger indicators. N) Attenuator buttons. O) Slope selection buttons. P) DC or AC coupling selection buttons. Q) Large LCD-display. R) Tilting support.

* The selected function is indicated on the display. A

short press on the button moves the cursor one

step to the right. A long press makes the cursor

scroll.

2-3 Front View

Product Presentation

This page is intentionally left blank.

2-4 Front View

Chapter 3

Installation

Unpacking

If the Timer/Counter is cold, leave it in the cardboard box until it has reached normal room temperature.

Lift the Timer/Counter out of the box.

–

Remove the polystyrene supports.

–

Unpack the Timer/Counter from the plastic bag.

–

Reverse the procedure to pack.

–

Check List

Has the Timer/Counter been damaged in transport? If it has, file a claim with the carrier immediately, and notify the Pendulum sales & service organization to make repair or re placement of the instrument easier.

Check that the package contains the following items in

–

addition to the Timer/Counter:

This Operators’ Manual

–

A power cable with protective earth conductor

–

An MTCXO oscillator if ordered option 07 *

–

A GPIB interface if ordered option 04 *

–

* Check marks on the rear panel indicate which op-

tions are fitted in your Timer/Counter.

Voltage Range Selection

Set the Timer/Counter to the local line voltage before con necting it. As delivered the Timer/Counter may be set to ei ther 115 V or 230 V. The setting is indicated on the voltage range selector on the rear panel.

115V

OFF

VOLTAGE

SELECTOR

SUPPOR TED FUNCTIONS: S H 1 , A H 1 T 5 , L 4 S R 1 , R L1 DC1, DT1 E2

LR 39484

230V

T H E R M A L F U S E IN

MAINS TRANSFORM ER

IE E E 48 8 IN T E R FA C E

INCLUDED OPTIONS

OPTION 04 OPTION 07 OPTION 08

OPTION __

OPTION __ OPTION __

TALK O NLY

EXT REF INPUT

10M Hz 0.5-15Vrms

ADDRESS

8421

Figure 3-2 Location of Voltage Range Selector.

IN C L U D E D O P T IO N S

OPTION 04

OPTION 07

OPTION 08

OPTION __

Figure 3-1 Options Label on

Rear Panel.

If the voltage range setting is incorrect, set the selector in accordance with the local voltage before

connecting the

power cable to the line.

3-2 Unpacking

Installation

Grounding

The Timer/Counter is connected to ground via a sealed three-core power cable, which must be plugged into a socket outlet with a protective ground terminal. No other grounding is permitted for this Timer/Counter. Extension ca bles must always have a protective ground conductor.

WARNING:Never interrupt the protective grounding

intentionally. Any interruption of the protec tive ground connection inside or outside the instrument, or disconnection of the protec tive ground terminal is likely to make the instrument dangerous.

Connecting External Reference

If you wish to use an external 10 MHz reference frequency source, connect it via a BNC-cable to the EXT REF INPUT on the rear panel of the Timer/Counter.

When the Timer/Counter starts measuring, it automatically detects the external reference and begins to use it. The EXT REF indicator on the display is switched on.

Rubber feet

Lockin g bar

Notch

Cut outs for BNC cables

Front plate

Sm all bracket

Large bracket

Figure 3-3 Option 06

Tools and equipment

To be able to install the Rack Mount Kit in a safe way, you need:

One Torx 10 screwdriver

–

Fitting Counter on the Rack Shelf

CNT-66 and CNT-69

Fit the small bracket with one countersunk screw through

–

the hole closest to the rear of the shelf.

R a c k s h e lf

Installing the Rack Mount Adapter

The option 06 is a 19" wide and 2E (88 mm) high Rack Mounting Adapter. It can host one CNT-66 or CNT-69 Coun ter.

Check list

Check that this box contains the following items:

–

One rack shelf.

–

One front plate.

–

One plastic bag containing:

–

One large and one small bracket.

–

One locking bar.

–

Three countersunk screws M3x8.

–

Two screws M3x8.

–

Two spring-washers for the above screws.

–

Two self adhesive rubber feet.

Besides the parts in the kit you will also need:

–

Four square nuts for your rack.

–

Four screws for the above nuts.

Figure 3-4 Fit the small bracket

with the countersunk

–

Fit the rubber feet according to Figure 3-4.

–

Fit the large bracket with two countersunk screws.

–

Turn the Counter upside down and remove the tilting sup port.

–

Engage the lower rear part of the counter-cover with the small bracket and lower the front of the counter until it rests on the rubber feet.

–

Fasten the counter by pressing the locking bar through the holes in the front feet of the counter.

3-3 Grounding

Installation

Figure 3-5 Fasten the counter with

the locking bar.

Turn the bar until it locks in the notch in the shelf.

–

If your measuring cables are inside the rack, then push

–

the BNC cables through the hole in the bracket before fit ting the front plate.

Fasten the front plate with the two M3x8 screws and lock

–

ing-washers.

Now fit the option 06 in your rack and connect the cables.

3-4 Installing the Rack Mount Adapter

Chapter 4

Operating Instructions

Using the Timer/Counter

CONTROL OPERATING THE

CONTROL

POWER, a two-position

STANDBY

FUNCTION

mechanical push-button. Depressed = ON, Released = OFF

A short depression of the FUNCTION button moves the cursor in the lower edge of the dis play one step to the right. If the button is held depressed, the cursor will scroll to the right un til released. When the cursor reaches the rightmost position it jumps back to the leftmost position and continues from there.

DISPLAY GPIB-CODE

AUTO

DISPLAYMEASURING TIME

10s1s0.2sSINGLE REF

HOLD

R E M O T E

TIME

RATIO

PERIOD

FREQ

PERIOD

FREQ

A-B

A/B

FUNCTION

DISPLAYMEASURING TIME

10s1s0.2sSINGLE REF

HOLD

TIME

RATIO

A-B

A/B

FUNCTION

COMMON

B via A

TOT A

COMMON

B via A

TOT A B

EXT

TOT A B

EXT

TOT A B

LEVEL

TOT A

MAN

AUTO

LEVEL

TOT A

MAN

READ

LEVEL

VOLTA MAX-MIN

READ

LEVEL

VOLTA MAX-MIN

No control possi ble but D gives the same settings as after power-ON.

One code for each function, see below:

Move function cursor to

FUNCTION

FREQ A

4-2 Using the Timer/Counter

FREQ

AUTO

DISPLAYMEASURING TIME

COMMON

10s1s0.2sSINGLE REF

HOLD

B via A

EXT

LEVEL

READ

LEVEL

FREQ A

(FREQ B possi

ble via Bus)

TOT A

TIME

RATIO

PERIOD

FREQ

A-B

A/B

FUNCTION

MAN

VOLTA MAX-MIN

Operating Instructions

FUNCTION AND RANGE HINTS AND COMMENTS

Switches the power ON and OFF. When switched on, the built in microprocessor switches on all segments of the display then it runs a power-up test, checking the measuring-logic of the Timer/Counter before the counter starts working. This test takes about 2 seconds.

If an error is found, an error code will be displayed. Try switching the Timer/Counter off and on again. If error code 01 - 03 persists, call Pendulum service. Look on the last page in this manual for Phone No. and address.

Selects one of the nine measuring functions available.

WARNING:The power switch operates on the secondary side of the transformer. The power cable must be disconnected from the line outlet socket if it is necessary to completely isolate the Timer/Counter from the line.

Error 01 = RAM memory error Error 02 = Measuring logic error Error 03 = Internal bus error Error OF = Overflow in the counting registers.

Reciprocal frequency measurement of the signal at In put-A.

Range:

0.1 Hz to 16 MHz (SINGLE measuring-time) 1 Hz to 160 MHz (0.2, 1, and 10 s measuring-time)

If the signal is sine shaped and the input AC coupled, the minimum input frequency is 20 Hz (at specified sensitivity).

4-3

Operating Instructions

CONTROL OPERATING THE

CONTROL

Move function cursor to

FUNCTION

FREQ C

Move function cursor to

PER A

Move function cursor to

RATIO A/B

Move function cursor to

TIME A-B

DISPLAY GPIB-CODE

AUTO LEVEL

TOT A

MAN

AUTO LEVEL

TOT A

MAN

AUTO LEVEL

TOT A

MAN

AUTO LEVEL

READ

LEVEL

VOLTA MAX-MIN

READ

LEVEL

VOLTA MAX-MIN

READ

LEVEL

VOLTA MAX-MIN

READ

LEVEL

FREQ C

PER A

RATIO A,B

(RATIO B,A RATIO C/A and RATIO C/B also possible via bus)

TIME A,B

(TIME B,A also possible via bus)

FREQ

DISPLAYMEASURING TIME

10s1s0.2sSINGLE REF

HOLD

TIME

RATIO

PERIOD

FREQ

PERIOD

FREQ

PERIOD

FREQ

A-B

A/B

FUNCTION

DISPLAYMEASURING TIME

10s1s0.2sSINGLE REF

HOLD

TIME

RATIO

A-B

A/B

FUNCTION

DISPLAYMEASURING TIME

10s1s0.2sSINGLE REF

HOLD

TIME

RATIO

A-B

A/B

FUNCTION

DISPLAYMEASURING TIME

10s1s0.2sSINGLE REF

HOLD

COMMON

B via A

TOT A B

COMMON

B via A

TOT A B

COMMON

B via A

TOT A B

COMMON

B via A

EXT

TOT A B

EXT

TOT A B

EXT

TOT A B

EXT

FUNCTION

Move function cursor to

TOT A B

Move function cursor to

TOT A B

Move function cursor to

TOT A MAN

FREQ

A-B

A/B

FUNCTION

DISPLAYMEASURING TIME

10s1s0.2sSINGLE REF

HOLD

COMMON

B via A

EXT

MAN

AUTO LEVEL

VOLTA MAX-MIN

READ

LEVEL

TOTG A,B

TOT A

TIME

RATIO

PERIOD

(TOTG B,A also possible via bus)

FREQ

A-B

A/B

FUNCTION

DISPLAYMEASURING TIME

10s1s0.2sSINGLE REF

HOLD

COMMON

B via A

EXT

MAN

AUTO LEVEL

VOLTA MAX-MIN

READ

LEVEL

TOTS A,B

TOT A

TIME

RATIO

PERIOD

(TOTS B,A also possible via bus)

FREQ

A-B

A/B

FUNCTION

DISPLAYMEASURING TIME

10s1s0.2sSINGLE REF

HOLD

COMMON

B via A

EXT

MAN

AUTO LEVEL

VOLTA MAX-MIN

READ

LEVEL

TOTM A

TOT A

TIME

RATIO

PERIOD

(TOTM B also possible via Bus)

TOT A

TIME

RATIO

PERIOD

FREQ

A-B

A/B

FUNCTION

MAN

VOLTA MAX-MIN

4-4

FUNCTION AND RANGE HINTS AND COMMENTS

Operating Instructions

Reciprocal frequency measurement of the signal at In

put-C.

Range:

70 to 1300 MHz

When you select SINGLE, the Timer/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 Timer/Counter divides the input frequency by 10 and mea sures the average period for the No. of cycles in that time. Range:

8nsto1s.

The number of pulses at Input-A and the number of pulses at Input-B are fed into one register each. When the set Measuring-time has elapsed, register A is divided by regis ter B.

Range:

1*10

–7

to 1.2*10

The Timer/Counter measures the time between a positive slope on Input-A and a positive slope on Input-B (default).

Range:

100 ns to 2*10

s (SINGLE) 0 ns to 20 s (average, the signal must be asynchronus with the time base)

Use SINGLE when the input frequency is low. This short ens the measuring time considerably since one cycle is measured instead of 10.

The signal with the lowest frequency must always be con nected to Input-B.

Use the SLOPE buttons if you wish to measure between any other combination of slopes.

The Timer/Counter counts the total number of pulses fed to Input-A. The positive slope of the Input-B signal starts the totalizing, and the negative slope stops it. This is al

ways a SINGLE measurement.

Range:

0 to 1*10

pulses.

The Timer/Counter counts the total number of pulses fed to Input-A. The positive slope of the first pulse on Input-B starts the totalizing, and the positive slope of the next pulse stops it. This is always a SINGLE measurement.

Range:

0 to 1*10

pulses.

The Timer/Counter counts the total number of pulses fed to Input-A. You start and stop the totalizing with the TOTALIZE START/STOP button (RESET/LOCAL). If you keep this button depressed for more than one second, the total sum will be reset.

Range:

0 to 1*10

pulses

k on the display indicates kilo-pulses (1000) and M indicates Mega-pulses (1 000 000).

Use the Input-B SLOPE button if you wish to measure dur ing a negative pulse on Input-B

k on the display indicates kilo-pulses (1000) and M indi

cates Mega-pulses (1 000 000).

Use the Input-B SLOPE button if you wish to measure be tween two consecutive negative pulses on Input-B.

k on the display indicates kilo-pulses (1000) and M indi

cates Mega-pulses(1 000 000).

The Measuring-time indicator is switched off in TOT A MAN.

4-5

Operating Instructions

CONTROL OPERATING THE

CONTROL

Move function cursor to

FUNCTION

VOLT A MAX-MIN

MEAS TIME is operated

M EAS TIM E

M EAS

in the same way as the functions control, see page

Move the measur

ing-time cursor to SINGLE

TIM E

DISPLAY GPIB-CODE

MAX VOLTAGE MIN VOLTAGE VMAX A,

PERIOD

FREQ

PERIOD

FREQ

DISPLAYMEASURING TIME

10s1s0.2sSINGLE REF

HOLD

TIME

RATIO

A-B

A/B

FUNCTION

DISPLAYMEASURING TIME

10s1s0.2sSINGLE REF

HOLD

TIME

RATIO

A-B

A/B

FUNCTION

COMMON

B via A

TOT A B

COMMON

B via A

TOT A B

EXT

TOT A B

EXT

TOT A B

AUTO LEVEL

TOT A

MAN

AUTO LEVEL

TOT A

MAN

READ

LEVEL

VOLTA MAX-MIN

READ

LEVEL

VOLTA MAX-MIN

VMIN A

(VMAX B and VMIN B possible via Bus)

MTIME <num>

where <num> is the time in sec onds.

Range:

10 ms to 10 s. 0 = Single

MTIME 0

M EAS TIM E

Move the measuringtime cursor to 0.2 s

Move the measuringtime cursor to 1s

Move the measuringtime cursor to 10 s

FREQ

AUTO

DISPLAYMEASURING TIME

10s1s0.2sSINGLE REF

HOLD

TIME

RATIO

PERIOD

FREQ

PERIOD

FREQ

PERIOD

FREQ

A-B

A/B

FUNCTION

DISPLAYMEASURING TIME

10s1s0.2sSINGLE REF

HOLD

TIME

RATIO

A-B

A/B

FUNCTION

DISPLAYMEASURING TIME

10s1s0.2sSINGLE REF

HOLD

TIME

RATIO

A-B

A/B

FUNCTION

COMMON

B via A

TOT A B

COMMON

B via A

TOT A B

COMMON

B via A

TOT A B

EXT

TOT A B

EXT

TOT A B

EXT

TOT A B

LEVEL

TOT A

MAN

AUTO LEVEL

TOT A

MAN

AUTO LEVEL

TOT A

MAN

READ

LEVEL

VOLTA MAX-MIN

READ

LEVEL

VOLTA MAX-MIN

READ

LEVEL

VOLTA MAX-MIN

MTIME 0.2

MTIME 1

MTIME 10

4-6

FUNCTION AND RANGE HINTS AND COMMENTS

Operating Instructions

The timer counter will measure the positive and negative peak voltage an display them as voltage relative to 0 V.

Range: –51 V to +51 V.

The set Measuring-time controls the time during which the main gate is opened, allowing pulses to enter 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 Mea suring-time, because the Timer/Counter synchronizes the measurement with the input signal in order 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.

For PER A and TIME A-B exactly one period or one time interval is measured. The minimum result possible is 100 ns.

The display time will be 100 ms.

When set to SINGLE and FREQ A, the Measuring-time is one cycle of the input signal or 3 ms, whichever is longest. When set to SINGLE and FREQ C, the Measuring-time is 3 ms.

The attenuator will switch in and out automatically when needed during voltage measurements regardless if AUTO LEVEL is selected or not.

If you wish to do one measurement instead of repetitive measurements, see DISPL HOLD.

When TOT A B or TOT A B is selected, the Measuring-time setting will be used to set the display time.

The input frequency is limited to 16 MHz for FREQ A and PER 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 to 7 digits on the display.

A Frequency-A measurement will result in 7 to 8 digits on the display.

A Frequency-A measurement will result in 8 to 9 digits on the display.

4-7

Operating Instructions

CONTROL OPERATING THE

CONTROL

RESET LO C A L

TO TALIZE

DISPL

RESET/LOCAL, a short press is enough for Re set. When the remote in dicator 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.

Switches ‘on’ or ‘off’ DISPL HOLD when de-pressed.

HOLD

35pF

M AX 30Vrms

D C - 1 6 0 M H z

Connect the signal to INPUT-A via a BNC-cable.

DISPLAY GPIB-CODE

AUTO

DISPLAYMEASURING TIME

10s1s0.2sSINGLE REF

HOLD

COMMON

B via A

EXT

TOT A

TIME

RATIO

PERIOD

FREQ

PERIOD

FREQ

FUNCTION

DISPLAYMEASURING TIME

10s1s0.2sSINGLE REF

HOLD

TIME

RATIO

A-B

A/B

FUNCTION

A-B

A/B

COMMON

B via A

TOT A B

EXT

TOT A B

LEVEL

TOT A

MAN

AUTO LEVEL

TOT A

MAN

READ

LEVEL

VOLTA MAX-MIN

READ

LEVEL

VOLTA MAX-MIN

X starts a new

measurement.

GATE OPEN

starts and

GATE CLOSE

stops Totalize MAN.

Not bus controllable, but Free-run OFF will give a similar function; See GPIB-bus opera tion.

4-8

M AX 30Vrms

Connect the signal to

INPUT-B via a

BNC-cable.

1M 35pF

DC/AC Switch

D C +Trigger level

Level

A C +S en sitivity

Slope

In p u t-A

Attenuator

In p u t-B

DC/AC Switch

D C +Trigger level

COM B via A

A C +S en sitivity

Level

Slope

C ountin g lo g ic

Operating Instructions

CONTROL OPERATING THE

CONTROL

One ATTx1/x10 push

ATTx1 x10

DC AC

button for each of input A and B. Switch the indi cator ON to select 10 times attenuation and OFF to switch off the at tenuator.

One SLOPE push-button for each of input A and B. Switch the indicator ON to select negative slope, and OFF to select positive slope.

One DC/AC push-button for each of input A and B. Switch the indicator ON to select AC and OFF to select DC.

NOTE: Sensitivity can be set when AC-coupled and Trigger Level when DC-coupled.

DISPLAY GPIB-CODE

ATT ON ATT OFF

You must first select input with INPA or INPB.

TRGSLP POS TRGSLP NEG

You must first select input with INPA or INPB.

COUPL AC COUPL DC

You must first select input with INPA or INPB.

AUTO LEVEL

SET A

A depression switches the AUTO LEVEL indicator on or off.

Depress the SET A or SET B button once and the indicator in the but

ton switches on. Now the auto level and Read level buttons have the arrow up and down func tion. Another press will switch off the function.

NOTE: Sensitivity can be set when AC-coupled and Trigger Level when DC-coupled.

AUTO

DISPLAYMEASURING TIME

COMMON

10s1s0.2sSINGLE REF

HOLD

B via A

EXT

LEVEL

READ

LEVEL

AUTO ON AUTO OFF

FREQ

FUNCTION

DISPLAYMEASURING TIME

COMMON

10s1s0.2sSINGLE REF

HOLD

B via A

EXT

A-B

A/B

MAN

AUTO LEVEL

VOLTA MAX-MIN

READ

LEVEL

Separate Codes

TOT A

TIME

RATIO

PERIOD

FREQ

for trigger level and sensitivity

SENS1 =20 mV SENS2 =50 mV SENS3 =100mV

FREQ

RATIO

PERIOD

A/B

10s1s0.2sSINGLE REF

TIME

A-B

FUNCTION

DISPLAYMEASURING TIME

HOLD

TOT A B

COMMON

B via A

TOT A B

EXT

TOT A

MAN

AUTO LEVEL

VOLTA MAX-MIN

READ

LEVEL

TRGLVL

<num> <num> = –5.1 to +5.1 V. You must first select input with INPA or INPB.

TOT A

TIME

RATIO

PERIOD

FREQ

FUNCTION

A-B

A/B

MAN

VOLTA MAX-MIN

4-10

FUNCTION AND RANGE HINTS AND COMMENTS

Operating Instructions

When the indicator in the button is OFF, the signal is un-attenuated; the trigger level range is –5 V to +5 V and the sensitivity can be 0.02, 0.05 or 0.1 V.

When the indicator is ON the signal is attenuated 10 times; the Trigger level range becomes –50 V to +50 V and the sensitivity becomes be 0.2 V, 0.5 or 1.0 V.

When the button indicator is ON, the active slope of the in put is changed from positive to negative.

Dual functions:

1) AC- or DC- coupled input.

2) Selection of variable sensitivity (AC) with 0 V trigger level or mum sensitivity.

NOTE: AC coupling together with Auto Level results in maximum sensitivity and automatic trigger level setting.

The auto-level function always sets the DC trigger-level to 50% of the amplitude, it does also switch on the attenuators when needed. Auto-level is selected simultaneously for both A and B inputs.

The measuring rate is reduced to about two measurements/ second when using Auto-Level.

selection of variable trigger level (DC) with maxi

If Auto Level or Volt is selected, the correct attenuator set ting will be selected automatically.

You can remove any DC-component with AC-coupling.

For frequency, period, and ratio measurements: Select AC-coupling and set the sensitivity so that the hysteresis band of the Timer/Counter is about half the amplitude of the input signal.

For time measurements: Select DC-coupling and set the trigger level to the desired level.

NOTE: Auto level gives automatic trigger level setting to AC coupled inputs also.

Use Read-Level to check what trigger-levels Auto-Level has selected

The sensitivity is decreased to 150 mVpp, and the minimum frequency is 100Hz

For frequency, period, and ratio measurements:

Select AC-coupling and set the sensitivity to about half the amplitude of the input signal.

For time measurements:

Select DC-coupling and set the trigger level to the desired level.

If the sensitivity is too high, the Timer/Counter will be trig gered by noise and interference instead of by the signal.

4-11

Operating Instructions

CONTROL OPERATING THE

CONTROL

The READ LEVEL push-button. When the indicator is on, the dis play shows the trigger levels on the display.

READ LEVE L

The COMMON B via A

COMMON B VIA A

70M H z - 1.3G H z

push-button. When the indicator is on the signal on Input-A is also con nected to Input-B.

Connect the signal to INPUT-C via a BNC-cable.

DISPLAY GPIB-CODE

LEVEL A LEVEL B Use INPA? and

DISPLAYMEASURING TIME

COMMON

10s1s0.2sSINGLE REF

HOLD

B via A

FREQ

A/B

10s1s0.2sSINGLE REF

A-B

FUNCTION

DISPLAYMEASURING TIME

HOLD

COMMON

B via A

TOT A

TIME

RATIO

PERIOD

FREQ

TOT A

TIME

RATIO

PERIOD

FREQ

A/B

A-B

FUNCTION

EXT

TOT A B

EXT

TOT A B

AUTO LEVEL

TOT A

MAN

AUTO LEVEL

TOT A

MAN

READ

LEVEL

VOLTA MAX-MIN

READ

LEVEL

VOLTA MAX-MIN

INPB? to read input settings to the controler

COM ON COM OFF

M AX 12Vrms

EXT REF INPUT

10M H z 0.5-15Vrm s

Connect an external 10 MHz frequency source to the BNC-connector on the rear panel of the Timer/Counter marked

EXT REF INPUT

FREQ

AUTO

DISPLAYMEASURING TIME

COMMON

10s1s0.2sSINGLE REF

HOLD

B via A

EXT

LEVEL

READ

LEVEL

Not bus control

lable.

TOT A

TIME

RATIO

PERIOD

FREQ

A-B

A/B

FUNCTION

MAN

VOLTA MAX-MIN

4-12

FUNCTION AND RANGE HINTS AND COMMENTS

Operating Instructions

When active, trigger levels will be displayed according to this table:

Auto Level Manual

Level selected

by Auto. Level selected

by auto

When active, the signal on Input-A is also connected to In put-B.

The DC/AC and Attenuator switches for Input-A affects both Input-A and B. The Input-B DC/AC and Attenuator switches have no effect. (See figure )

Trigger level/sensitivity and Slope can be selected sepa rately.

This is the HF-input which must be used when the FREQ-C function is selected.

Range:

70 to 1300 MHz.

Impedance:

50W

Sensitivity:

10mV

and 40 mV

Max voltage:

12 V

up to 900 MHz, 15 mV

RMS

RMS.

above.

Level set using Set A or SET B

0V.

RMS

900-1100 MHz

Use Read-Level to check what trigger-levels Auto-Level has selected.

You can use COM B via A and the manual trigger level

settings to make accurate rise-time measurements:

1. Select DC-coupling, COM B via A and positive slope

for input A and B.

2. Select VOLT A MAX-MIN and read the amplitude of

the signal.

3. Calculate 10 % of the peak to peak voltage.

4. Depress SET A, use and to set trigger level A to

the MIN reading plus the 10 % of Vpp.

5. Depress SET B, use and to set trigger level B to

the MAX reading minus the 10 % of Vpp.

6. Select TIME A-B

RATIO C/A and RATIO C/B can be selected via the bus

The Timer/Counter automatically detects if a suitable signal is connected to the EXT- REF Input-connector.

Suitable signal:

10 ± 0.1 MHz, 0.5 to 15 Vrms Sine wave.

Use external reference when the measurement requires ul tra-high stability.

The Timer/Counter must still have the internal time base even if an external reference frequency is used.

If single is selected, the EXT REF indicator on the display is not switched on until after the first measurement.

4-13

Operating Instructions

Error Codes

The counter can display the following error codes if some thing goes wrong.

Error OF Overflow in the counting registers. Select a

shorter Measuring-time if you get this error code, unless the counter is set to TOTALIZE, then you must press reset and start again

from zero. Error 01 RAM memory error Error 02 Measuring logic error Error 03 Internal bus error

If the counter shows one of these error codes, try switching the counter off and on again. If error code 01-03 persists, call Pendulum service. Look on the last page in this manual for Phone No. and address.

4-14 Error Codes

Chapter 5

GPIB-interface Operation

Introduction

The CNT-66 can be controlled by a computer (controller) via the GPIB-interface option, option 04. All functions that can be controlled from the front panel can also be controlled via the bus in a similar way, except the power switch. The addi tional micro-processor on the interface board has made it possible to add functions. You can obtain continuously vari able Measuring-time, bus-learn, high-speed-dump etc., but these functions are only accessible via the bus.

To select a function, you send a command to the counter. We have chosen the text on the front panel as commands, wherever possible, in order to make them easy to remem ber. E.g. the command to select Frequency-C is FREQ C and the command to select Ratio A/B is RATIO A,B.

NOTE: The characters in a command can be in both up

per and lower case.

What can I do using the Bus?

Summary

Description Code

Source handshake SH1 Acceptor handshake AH1 Control function CØ Talker Function T5 Listener function L4 Service request SR1 Remote/local function RL1 Parallel pol PPØ Device clear function DC1 Device trigger function DT1 Bus drivers E2

Source and Acceptor Handshake SH1, AH1

SH1 and AH1 simply means that the counter can exchange data with other instruments or a controller, using the bus handshake lines; DAV, NRFD, NADC.

It can send out a status byte as response to a serial poll

–

from the controller.

Automatic un-addressing as talker when it is addressed

–

as a listener.

Listener Function, L4

The counter can receive programming instructions from the

controller. L4 means the following functions:

Basic listener.

–

No listen only.

–

Automatic un-addressing as listener when addressed as

–

a talker.

Service Request, SR1

The counter can call for attention from the controller e.g. when a measurement is completed and a result is available.

Remote/Local, RL1

You can control the counter manually (locally) from the front panel, or remotely from the controller. The LLO, lo cal-lock-out function, can disable the LOCAL button on the front panel.

Parallel Poll, PPØ

The counter does not have any parallel poll facility.

Device Clear, DC1

The controller can reset the counter, forcing it to default settings, via interface message DCL (Device clear) or SDC (Selective Device Clear).

Device Trigger, DT1

You can start a new measurement from the controller via in terface message GET (Group Execute Trigger).

Bus Drivers, E2

The GPIB interface has tri-state bus drivers.

Control Function, CØ

The counter does not function as a controller.

Talker Function, T5

The counter can send responses and the results of its mea surements to other devices or to the controller. T5 means that it has the following functions:

–

Basic talker.

–

Talk only mode.

5-2 Introduction

GPIB-interface Operation

Connecting the Controller

The bus interface connector is on the rear panel of the counter. If your counter does not have any connector, you must install the GPIB-interface option, see installation.

G P IB connector A ddress sw itch

OFF

VOLTAGE

SELECTOR

SUPPOR TED FUNCTIONS: S H 1 , A H 1 T 5 , L 4 S R 1 , R L1 DC1, DT1 E2

LR 39484

T H E R M A L F U S E IN

MAINS TRANSFORM ER

IE E E 4 8 8 IN TE R F A C E

INCLUDED OPTIONS

OPTION 04 OPTION 07 OPTION 08

OPTION __

OPTION __ OPTION __

TALK O NLY

EXT REF INPUT

10M Hz 0.5-15Vrms

ADDRESS

8421

Figure 5-1 GPIB connector and address

switch, the numbers above the switches indicate the significance of each switch.

Connect the controller via an IEEE-488 cable to the bus connector. If you use IEC-625 cables, an adapter is available, see ordering information at the end of this manual.

Giving the Counter an Address

The counter must have a unique address so that the con troller can communicate with it. The address is selected by setting switches to the binary equivalent of the address you want. The switches are located to the right of the interface connector. The OFF position means 0 and the ON position means 1.

Address

Switch settings

Address

Switch settings

Address

Switch settings

0 00000 10* 01010 20 10100 1 00001 11 01011 21 10101 2 00010 12 01100 22 10110 3 00011 13 01101 23 10111 4 00100 14 01110 24 11000 5 00101 15 01111 25 11001 6 00110 16 10000 26 11010 7 00111 17 10001 27 11011 8 01000 18 10010 28 11100 9 01001 19 10011 29 11101

30 11110

NOTE: 31 is the bus command for “Untalk” and should

not be used. If 31 is selected the counter will work as if address 0 is selected.

Talk-Only

The leftmost switch in the address switch block is the TALK ONLY switch. If you set it to ‘1’, the counter will output mea surement results on the bus continuously. It will not react to any incoming commands.

This setting may only be used if the counter is connected to a ‘Listen only’ device such as a printer. Set the switch to ‘0’ when you want normal bus communication.

Talk only is set to ‘0’ on delivery. The counter is now ready for bus control.

Checking the Communication

To check if the counter and the controller can communicate, address the counter and execute the following sequence: (The programming example is for an HP-85 controller.)

Type on controller: This should happe:n

REMOTE 710 The remote indicator should

be switched on.

OUTPUT 710;"ID?" Ask for the counter identity. ENTER 710;A$ Input result from counter. DISP A$ The response on the display of

the controller is the identity of the counter.

If everything is OK, the counter will identify itself as:

PM6666/YZW/MN

where: Y = 4 if the counter has an HF-input, otherwise 0. Z = 3 for MTCXO, otherwise 1 W = 6 (GPIB-bus is installed) M = Revision No. of counter firmware N = Revision No. of GPIB-bus firmware

* Factory setting.

5-3 Connecting the Controller

GPIB-interface Operation

Two Ways of Programming

The simplest way of programming the counter is by manu ally setting up the measurement you want from the front panel of the counter, then let the controller ask the counter how it is set up. The data the controller gets from the coun ter can be used to set up the same measurement over and over again. This method is called ‘Bus-learn’ and will be ex plained later.

The other method is to make a program message where each step of the set-up is separately specified.

Programming Checklist

Check that the following steps have been taken to ensure correct programming of the instrument.

Normally only the six first steps must be programmed.

Do you know the current setting of the counter? If not,

–

send device clear ‘D’ to get the default settings.

Select Measuring-function; (Default: Frequency-A.)

–

Select Measuring-time;(Default: 0.2 s.)

–

Select Trigger-slopes;

–

(Default on Input-A and Input-B: Positive.)

– Select Coupling;

(Default on Input-A: AC.) (Default on Input-B: DC.)

–

Select Trigger-level;(Default: AUTO.)

For advanced programming, check the following steps.

–

Set Output separator; (Default: LF.)

–

Set EOI mode; (Default: OFF.)

–

Set service request(SRQ) -mask; (Default, No SRQ.)

–

Select Free-Run on or off; (Default: ON.)

–

If Free-Run is off, select Time-Out if desired; (Default: Infinite, programmed as 0 s.)

–

Set Output-mode; (Default: Normal output format, High-speed dump OFF and MTCXO compensation ON.)

Syntax

What is a Programming

Command?

A programming command consists of a header, addressing the function you want, and a body instructing the function

what to do.

EXAMPLE:

TRGSLP POS

HEADER, addressing Trigger slope

NOTE: Some programming commands consists only of

the Header, e.g. trigger command ‘X’.

What is a Programming Message?

A programming message is a number of programming com mands with separators between them. E.g. the commands necessary to set up a measurement.

EXAMPLE: PER A;MTIME 0

Input Separator

All communication between the counter and the controller uses sequences of ASCII-characters terminated by a separator. Input separators are the separators sent by the controller. They are used in four different places:

The separators in the example above are the ones normally used in respective place. The counter will however accept any one in any place.

Between header and body

As unit separator between bodies

TIME A,B;FRUN ON¿

BODY, switching Slope to positive

Between program commands

To end a program message

All functions and commands in the checklist will be ex plained later.

NOTE: You only have to program the changes from the

previous set-up.

5-4 Two Ways of Programming

The following separators will also work in any of the four places: colon, CR, ETB, ETX, the separator selected as out put separator, as well as an active EOI-signal.

GPIB-interface Operation

Order of Commands in a Program Message

Normally, the programming commands in a programming message can be placed in any order.

However, the following commands must always be placed at the end of a program message since any command sent after them will disable the selection:

INPA? MEAC? FNC? X INPB? BUS? ID? OUTM 4

These commands will be ignored if found anywhere but in the end of a message.

In some program commands, the body is replaced by the term <number> or <num>. Here you must enter a numerical value. <number> can be entered in any format you like e.g.

1.23 can also be entered as 0.000000123*10 1230000*10 needs, your entry will be truncated. The counter will stop if an entry is out of the counters range. To proceed, the status message ‘Programming error’ must be reset, see ‘Status byte’.

–6

. If you enter more digits than the counter

How to Select Function

Standard Functions

Functions are selected by sending the appropriate function command to the counter, e.g. FREQ A. The space between FREQ and A indicates the input separator that you always must insert.

Function Command Comment

Frequency A FREQ A Default Frequency C FREQ C Period A PER A Ratio A/B RATIO A,B Time A-B TIME A,B Totalize A Gated

by B Totalize A

Start/stop by B Totalize A

Manually Volt A max VMAX A Volt A min VMIN A

The function cursor on the display of the counter will jump to the selected function.

TOTG A,B

TOTS A,B

TOTM A See ‘Totalize

start/stop’

Selecting Output Separator

Output separators terminate messages from the counter to the controller. The separator needed is different for different controllers; see the Operators’ Manual for your controller.

At power on, the output separator of the counter is linefeed

decimal

dec

+10

), it is se

dec

‘LF’ (10

The output separator can be changed by sending SPR <number> to the counter. <number> is the decimal value of the ISO (ASCII)-code for the desired separator. It can be 0-26, 28-31, ESC code, 27, is not accepted.

Only one <number> can be entered as separator. If you want the combination of CR+LF (13 lected by ‘SPR 255’.

EXAMPLE:

SPR 13 changes the output separator to CR SPR 255 changes the output separator to CR+LF

The counter can signal EOI together with the last output separator in responses and output data.

EOI ON switches on the function. EOI OFF switches it off. Default setting is EOI OFF.

The selected separator and EOI will not be altered by LOCAL from the front panel nor by LOCAL or ‘Device clear’ from the bus.

Functions Accessible via Bus Only

When you have a GPIB interface you will get the following new functions:

Function Command Function cursor

Frequency B FREQ B FREQ A Time interval

B-A Totalize B

Manually Totalize B Gated

by A Totalize B

Start/stop by A Ratio B/A RATIO B,A RATIO A/B Ratio C/A RATIO C,A RATIO A/B Ratio C/B RATIO C,B RATIO A/B Volt B max** VMAX B VOLT A MAX-MIN Volt B min** VMIN B VOLT A MAX-MIN

** Don’t use VMAX B or VMIN B together with COM

B via A to measure the voltage on input A. The re sults will be unreliable.

When the counter switches to LOCAL, the function indi cated by the Function-cursor will be selected.

TIME B,A TIME A-B

TOTM B TOT A MAN

TOTG B,A

TOTS B,A

indicates

TOT A B

5-5 Selecting Output Separator

GPIB-interface Operation

The counter will not return to the ‘bus only’ function when it returns to remote. To return to the ‘bus only’ function you must re-program the counter.

The specifications of some ‘bus-only’ functions differ from the specifications of it’s similar front-panel selectable func tion. See ‘Specifications’.

Selecting Measuring-Time

The Measuring-time can be set to any value between 10 ms and 10 s, or SINGLE-measuring. Any value below 10 ms will be interpreted as SINGLE. Values above 10 s will be out of range and cause an error. The program command is MTIME <number>. Always enter the Measuring-time in sec onds. The entered value will be trunkated to the nearest 10 ms increment.

Meas Time Command Comment

0.2 s MTIME 0.2 Default 10 ms MTIME 0.01 You will not be able to see

7.34567s MTIME 7.34567 The Measuring-time will be

2 ms MTIME 0.002 Out of range SINGLE MTIME 0 A display time of 50 ms is

25 s MTIME 25.0 Out of range and error, the

The Measuring-time cursor on the display will indicate 0.2 s for all programmed Measuring-times except SINGLE, which will be indicated as usual.

the gate indicator blinking if the Measuring-time is below 50 ms

7.34 s.

set so that you can see the Gate-indicator.

counter will stop. It can indicate programming error by sending an SRQ if selected in the SRQ-mask.

Selecting Input settings

Before selecting input settings you must tell the counter which input you want to address:

Input Command Comment

A INPA Default setting B INPB

Now you can send the input setting commands:

Attenuator Command Comment

1 ATT OFF Default 10 ATT ON

Trigger slope Command Comment

Positive TRGSLP POS

Negative TRGSLP NEG

Coupling Command Comment

AC COUPL AC Default on A DC COUPL DC Default on B

Sensitivity Command Comment

SENS <number> 20 mV SENS 1 Default 50 mV SENS 20 100 mV SENS 3

If ATT10 is selected sensitivity will be 0.2 V 0.5 V and 1.0 V

Trigger level Command Comment

Volt TRGLVL <num><num> = trig-

* If ATT10 is selected, Trigger level range will be

51 V to +51 V and the minimum increment 0.2 V.

ger level in Volts. Range: 5.10V to +5.10V. Minimum increment:

0.02 V. Default 0 V

5-6 Selecting Measuring-Time

The following commands affect both inputs regardless of which input is selected:

Auto level Command Comment

Automatic AUTO ON Default Manual AUTO OFF

* If AUTO is ON, the attenuator, trigger level and

sensitivity settings are controlled by AUTO. If any of these parameters are reprogrammed when AUTO is ON, the new setting will be stored and used when AUTO is switched OFF. If the controller asks for program data out during AUTO, the an swer will be the selections made by AUTO.

GPIB-interface Operation

Common B

Command Comment

via A

on COM ON off COM OFF Default

When COM ON is selected, the AC/DC and attenuator set tings of Input-A will affect both channels. If AC/DC or the at tenuator of input-B is reprogrammed during COM ON, the setting will be stored and used when COM is switched OFF. The program data out for Input-B will be the programmed settings, not the Input-A settings used during COM ON.

Totalize Start/Stop

When TOT A or TOT B manual is selected, the gate is opened and closed by the controller instead of by pressing the button on the front panel. To start the counting after se lecting TOTM A or TOTM B, the gate must be opened.

Totalize Command Comment

Start GATE OPEN Starts counting Stop GATE CLOSE Stops Counting.

NOTE: Multiple GATE OPEN/GATE CLOSE will accumu-

late the results in the counting registers. Any other command but GATE OPEN/GATE CLOSE will stop the totalizing and reset the counting registers to zero.

Default

Free-Run/Triggered

The counter can work in two different ways:

1. Free-Run, where it starts a new measurement as

soon as the previous measurement is finished.

The first measuring result that is ready after the counter re ceives a read command, will be sent to the controller. When the result has been read, the output buffer is reset to zero until a new result is ready. One and the same measuring re sult can only be read once.

2. Triggered, where the counter waits for trigger com mand GET or ‘X’ from the controller before it starts a measurement. When the measurement is com pleted, the counter will wait until the controller reads the measuring results, then the output buffer is reset. The function is the same as when Displ Hold is selected from the front panel and you start a new measurement by pressing the Reset button.

Free run Command Comment

Off FRUN OFF This function is some

times called Trig gered-Mode

On FRUN ON TRIG OFF gives the

same result. Default.

Free-Run ON or OFF will not be indicated on the display. When the counter switches to LOCAL, Free-Run will always be ON but when the counter switches back to remote, it will return to its previously programmed settings.

Time-Out

When Free-Run is switched off it is possible to set a time-limit (time-out) between the start of a measurement and the time when a result is expected to be ready. If no re sult is achieved before the set time is out, the counter can output a Service Request, SRQ. Time-Out must be se lected in the SRQ-mask; see ‘Service Request’. The pro gramming command is TOUT <number>. The timeout can be set to any value between 100 ms and 25.5 s, the mini mum increment is 100 ms.

Time-Out Command Comment

100 ms TOUT 0.1 Time-Out is only intended to

be used with Free-Run off*.

Off TOUT 0 Always send this command

when Free-Run is switched on. Default.

Time-Out is not indicated on the display. When the counter switches to LOCAL, Time-Out is off, but when switched to remote again, the set Time-Out will be active again.

* Time-out can be switched on when free-run is on

but it will not serve any purpose.

5-7 Totalize Start/Stop

GPIB-interface Operation

Bus Triggering

‘X’ will always cause the counter to start a new measure ment. X will work as group execute trigger, GET. ‘X’ must al ways be placed in the end of a program message.

Service Request

The counter can send a service request, SRQ, when it wants service from the controller. After an SRQ, the con troller must execute a serial poll which means that it must ask each of the instruments for status information until it finds the SRQ-giving instrument, evaluate the Status-byte of the instrument and then make a decision what to do.

To enable the counter to send service requests, you must set an SRQ-mask telling the instrument which conditions will cause SRQ.

Command Comment

MSR <number> <number> is a decimal value depending

Bit Decimal

on selected SRQ reasons.

Reason for SRQ.

value

7 128 Not used 6 64 Time-Out 5 32 Hardware fault 4 16 Programming error 3 8 Measuring stop enable 2 4 Measuring start enable 1 2 Ready for triggering 0 1 Measuring result ready*

* If SRQ for Measuring result ready is selected, the

counter will stop and wait until the controller fetches the result before a new measurement can start.

Write down the binary word for the required SRQ, then con vert it to a decimal value and insert the value as <number>.

EXAMPLE: If you want SRQ to be sent when the time-out elapses, when the counter is ready for triggering and when the result is ready, the binary word required is 01000011 which is decimal 67; see table below.

Bit Value if the

bit is 1 Example

Binary

word

7 128 0 0 6 64 1 64 Time-Out 53200 41600 3800 2400 1 2 1 2 Ready to

0 1 1 + 1 Meas. Re

Send MSR 67 to the counter.

Decimal

value

trigger

sult ready

Status Byte

The counter sends its status byte to the controller on a serial poll. The bits in the status byte reflects different events or con ditions in the counter. There are two types of status bits:

A Conditional Bit indicates the current condition of what its monitoring, all the time.

An Event Bit indicate that an event has occurred. When the event occurs, the bit is set to 1. It is not reset to 0 until a new measurement starts.

The different bits indicate the following information:

Bit Function

7 Always 0 6 1 = SRQ has been sent’ otherwise 0 (Event bit) 5 Abnormal bit. Always 0

during normal measure

ments 4 0 = Main Gate closed 1 = Main Gate open** 3-0 Depends on Abnormal bit see below (Event bits.)

Bit Abnormal bit = 1 Abnormal bit = 0

3 Not Used Measuring stop enable 2 Time-Out Measuring start enable 1 Hardware fault Ready for triggering 0 Programing error Measuring result ready

* Only if SRQ-mask is set for Service-Request. ** This is a conditional bit that monitors the

Main-Gate in the counter. When TOT MAN is selected the bit will always be 0.

Measuring Start Enable indicates that the counter logic is ready to start a measurement.

Measuring Stop Enable indicates that the counter logic ir

ready to stop a measurement.

These bits can be used to detect if the input signal to the counter is present; If the counter never stops it’s measure ment and the status byte stops at:

XX00X1XX No input signal. The measurement is ready

XX011XXX Input signal lost during measurement. The

(X = don’t care)

NOTE: SRQ is normally not used for these bits.

Ready For Triggering indicates that all preparations for a measurement is completed. The preparation time depends on selected functions. It can be up to 700 ms (when auto triggering is selected).

If triggered mode is selected, the counter waits to be trig gered, otherwise it proceeds with the measurement. You can have the SRQ-mask set for SRQ at ready for triggering. This way the controller knows when it is possible to trigger the counter.

to start (bit2=1)buttheMain Gate has not opened (bit4=0)

measurement is ready to stop (bit3=1)but the main gate is still open (bit4=1)

1 if something is wrong. Affects bit 0-3

5-8 Service Request

GPIB-interface Operation

Measuring Result Ready indicates that the measurement and calculation of the result is completed and that the result is present in the output buffer. If SRQ for is selected for this event, or Free-run is OFF, the counting will stop until the controller has read the result.

Programming Error is generated if the counter receives messages with illegal syntax or values out of its range.

If ‘Programming error’ is generated, the counter will stop measuring. It will continue to receive and store correct pro gramming messages and use them when the error status is reset and a new measurement starts.

Correct the program before resetting the status message.

Use one of the following bus commands to reset the status byte:

Go to local (GTL), Device clear (DCL) or selective device clear (SDC).

Any of the following messages will have the same effect on the counter:

D, FNC?, MEAC?, INPA?, INPB?, ID? or BUS?.

A serial poll will also reset the status message if the SRQ mask is set for ‘SRQ at Programming error’.

Hardware Fault is generated when the counter displays the codes described in ‘Error codes’ in the ‘Operating instructions’ in this manual.

Time-Out is generated when the set time-out period has elepsed.

Possible Status Messages

Normal Measurement

The status byte changes as follows during a normal mea surement:

0, 2, 6, 22, 30, 14, 15, 0, .........

Decimal

0 00000000 Preparing a mea

2 00000010 XX0XXX1X Preparations ready.

6 00000110 XX0XX1XX Measuring start en

22 00010110 XX01XXXX Main-Gate open 30 00011110 XX0X1XXX Measuring stop en

14 00001110 Calculating the

15 00001111 XX0XXXX1 Measuring result

Binary 76543210

Error conditions

Binary

Decimal

33 00100001 XX1XXXX1 Programming error 34 00100010 XX1XXX1X Hardware fault 36 00100100 XX1XX1XX Time-out

76543210

Important bits(X= don’t care) Comment

surement or, High-speed dump or Volt measure ments in progress.

If Free-run OFF

able.

measuring result.

ready

Important bits(X= don’t care) Comment

* If Service request (SRQ) is enabled for an event,

the decimal value of the status message for that event will be increased by 64. The reason for this is that bit 6 will be set to one at the same time as the bit indicating the event.

5-9 Status Byte

GPIB-interface Operation

Output Mode

Setting the output mode selects the format in which the counter will output measuring results to the controller. Se lect output mode by sending OUTM <number> where <number> is a decimal value between 0 and 4 depending on the selected output mode.

<number> High-speed

dump

0 OFF NORMAL ON 1 OFF SHORT ON 2 OFF NORMAL OFF 3 OFF SHORT OFF 4 ON FOR

Output format

HIGH SPEED DUMP

MTCXO compensation

OFF **

Short

Short format means that function command and leading ze ros are not sent to the controller. When you select short out put format, the number of digits may vary depending on the

measurement result. The example below shows a result

with five significant digits:

Measurement result, same number of digits as on the display of the counter; may vary between 1 and 9 digits, plus decimal point. No leading zeros are sent.

Same as for normal output format.

X.XXXXE±XS(S)

EXAMPLE:

Normal operation:

1.667E–4

Overflow:

9.99999999E+9

Default <number> is 0, when switching to local and back again, the <number> will be reset to 0.

The MTCXO compensation can be switched off to increase the measuring speed, providing a result with five digits ac curacy is sufficient. The time gained will be up to 400 ms/measurement.

** Must be in the end of a program message.

Output Format

Normal

When you select normal output format, the output will be as follows:

Function command Header, 3-6 characters (same Header as used for selecting the function).

O when overflow, otherwise space

Measurement result, always 9 digits and a decimal point. Same number of significant digits as on the display of the counter, leading zeroes fill out the rest of the 9 positions. The leftmost digit can be replaced by a (minus sign)

Separates the exponent from the digits.

Exponent sign, + or –. Exponent, one digit. Output separator. LF if CR+LF is selected

as output separator.

FFFFFFOXXXXXXXXXXE±XS(S) 21(22) characters

EXAMPLE:

Normal operation:

PER 000001.667E–4

Overflow:

PER O9.99999999E+9

High-speed Dump

The most time-consuming part of a measuring cycle is cal culating the result. The calculations limit the number of pos sible results/second to about 5, even when the Measuring-time is short.

When however High-Speed dump is selected all calculations are left to the controller instead, and the counter can concentrate on measuring at a rate of over 100 measurements/second.

High-speed dump cannot be used for voltage measurements nor for Totalize manually. MTCXO compensation is not possible.

Starting

NOTE: Allways make sure you have input signal and that

the input triggers correctly before turning on high-speed dump! (See Stopping below).

If Triggered Mode is OFF When High-speed dump is pro

grammed the counter will immediately start transmitting re sults, so the OUTM 4 command must always be placed at the end of the program message.

If Triggered Mode is ON After receiving OUTM 4 the coun ter waits for bus command GET before it starts.

NOTE: The minimum time between OUTM 4 and GET is

70 ms.

Stopping

Any programming command from the controller will end High-Speed dump. High-speed dump is stopped inbetween two measurements. If you switch on high-speed dump without having an input signal, the counter must be switched off/on to regain control over the counter.

NOTE: The Power-switch is the only front panel control

that will stop High-Speed dump, the LO CAL-button will not have any effect.

5-10 Output Mode

Output Format

The output format will always be two letters followed by 12 hexadecimal digits. The two letters will tell the controller how to evaluate the twelve hex-digits, which represent the contents in the internal registers of the counter.

Formula

Multiplier

Hex-digits

Separators*

FM111111222222S(S) 15(16) characters

* The counter cannot signal EOI together with the

output separator when High-speed dump is se

lected.

Hex-digits

All 12 digits together represent register 3.

MSB

LSB

111111222222 = = 333333333333

When the digits are divided into two groups, the first six digits represents register 1 and the last six digits represent register 2.

LSB

MSB

111111

MSB

222222

LSB

Formula

Depending on the selected measuring function different cal culations must be made to convert the register contents to readable measuring results.

The first letter (F) in the output data indicates which formula you must use.

If ‘F’= Use this formula

F G

J K

Reg

Reg .3 Reg

Reg

Reg .3 1 0 Reg

210

Reg..

210

Reg..

110

Reg..

210

Reg..

7´-

GPIB-interface Operation

Multiplier

The second letter (M) in the output data represents a multi plier which you must multiply the results by before present ing it.

If ‘M’= Multiply results by:

H60 L 256 N 0.1 O10 P1

EXAMPLE 1:

The following HP-85 program sets up a High-Speed dump Single-period measurement.

OUTPUT 710;"PER A,MTIME 0" ENTER 710;A$ A$ PER 000001.667E–4 OUTPUT 710;OUTM 4 ENTER 710;A$ A$ JP000000000683

‘J’ means that you must use formula J which is:

Reg.*310

000000000683 is the hex-contents of register 3. The register contents must be converted to a decimal number and entered in the formula;

683 6 16 8 16 3 1667

Hex Decimal

The result is 1667*10 plier P”, which is 1, to get the measuring result.

1667 10 1 1667 10 166 7

EXAMPLE 2:

The following HP-85 program sets up a High-Speed dump Frequency A measurement with 1 s Measuring-time.

Formula ‘C’ is:

98555B is the hex-contents of register 1, and 000257 is the hex-contents of register 2. Both register contents must be converted to decimal numbers and put into the formula;

916 816 516 516 51611

´+´+´+´+´+

= 600 0006209. ...

=´ +´ +=

–7

. which you must multiply by “Multi-

´´= ´ =

..ssm

OUTPUT 710;"FREQ A,MTIME 1" ENTER 710;A$ A$ FREQ 006.000006E3 OUTPUT 710;OUTM 4 ENTER 710;A$ A$ CO98555B000257

210

Reg..

Reg

()216 5167 10

´+´+´

54 32

5-11 Output Mode

GPIB-interface Operation

This number is multiplied by multiplier ‘O’ to get the measur ing result:

6000006209 10 6000006209 6 000006209 10

...´= = ´ Hz

How many digits are significant?

Select the formula for ‘LSD displayed’ in the ‘Specifications’. There are different formulas for different measurements.

Frequency:

....

25 10 6000

LSD displayed :

LSD = 0.001 Hz

The result is 6.000006*10

´´

00015

Bus Learn

Set the counter to LOCAL and select the functions you

–

want from the front panel. If required, set the counter to Remote and program spe

–

cial bus-functions from the controller. Check that the counter/controller performs the intended

–

functions. If it does, send the five queries from the controller to the

–

counter and store the responses in the controller for later use.

These are the five queries:

Max No. of

Query Response

FNC? Functions setting; e.g. FREQ A9 9 MEAC? Measurement control;

INPA? Input A settings;

INPB? Input settings;

BUS? Bus interface commands;

MTIME <number>,FRUN ON TOUT <number>

TRGSLP POS,ATT OFF COUPL AC,AUTO OFF TRGLVL <number>,SENS 1

TRGSLP POS,ATT OFF B COUPL DC,COM OFF TRGLVL <number>,SENS 1

MSR <number>,OUTM <number> EOI OFF,SPR <number>

characters

20 9

18 17 19

18 16 19

NOTE: The query command must always be the last

command in a program message.

* If AUTO or COM is switched ON, the responses to

INPA? and INPB? must be interpreted in a different way, see ‘Selecting Input settings’.

Terminating a Response

It is not necessary to read all output lines. Any program message will terminate the response.

Programming Data Out

Any one of the queries used for Bus Learn can be used to ask the counter about its current setting, see ‘Bus Learn’ above.

What Happens When I Switch to Local?

Switching to LOCAL causes the counter to adapt the set tings indicated on the display, see ‘How to select function’. This means that the counter will never have settings in LO CAL which are not possible to set via the front panel.

When switching to remote again, the LOCAL-setting will remain. Bus-functions like SRQ mask, output separator, EOI, etc. will not be altered by switching to LOCAL and back again.

As you can see, the responses are the same commands as you use for normal programming. So if you have to change anything in a program made using bus learn, or add func tions which are not selectable from the front panel, these program messages can easily be edited in the controller.

NOTE: MEAC? and BUS? result in a response sent as

two lines, each terminated by the selected sepa rator. INPA? and INPB? result in a response sent as a three line messages.

NOTE: The counter will stop measuring until all lines of

the response have been read or the response has been terminated.

5-12 Bus Learn

GPIB-interface Operation

Summary of Bus Commands

Function Selecting Commands

FREQ A Frequency measurement on Input-A FREQ B Frequency measurement on Input-B FREQ C Frequency measurement on Input-C PER A Period on Input-A TIME A, B Time interval A to B TIME B, A Time interval B to A TOTG A, B Totalize A, gated by Input-B TOTG B, A Totalize B, gated by Input-A TOTS A, B Totalize A, started and stopped by B TOTS B, A Totalize B, started and stopped by A TOTM A Totalize A, start/stop by

GATE OPEN/CLOSED on the bus.

TOTM B Totalize B, start/stop by

GATE OPEN/CLOSED on the bus RATIO A, B No. of pulses on A No. of pulses on B RATIO B, A No. of pulses on B No. of pulses on A RATIO C, A No. of pulses on C No. of pulses on A RATIO C, B No. of pulses on C No. of pulses on B VMAX A Positive peak voltage on Input-A VMIN A Negative peak voltage on Input-A VMAX B Positive peak voltage on Input-B VMIN B Negative peak voltage on Input-B FNC? Output the current function setting

Input Setting Commands

INPA Selects Input-A INPB Selects Input-B TRGSLP POS Triggering on positive slope TRGSLP NEG Triggering on negative slope COUPL AC AC coupling COUPL DC DC coupling COM ON A and B common via Input-A COM OFF A and B separated SENS <num> <num> = 1 gives 20 mV sensitivity

<num> = 2 gives 50 mV sensitivity <num> = 3 gives 100mV sensitivity.

TRGLVL<num> Trigger level, +5.10 V to –5.10 V. =

polarity sign. <num> = level in Volt. AUTO ON Automatic trigger level selection ** AUTO OFF Trigger level selection via bus ** ATT OFF Attenuation 1 ATT ON Attenuation 10 INPA? Output the current Input-A settings INPB? Output the current Input-B settings

Measurement Control Commands

GATE OPEN Starts the totalizing in TOTM A and

GATE CLOSE Stops totalizing MTIME <num> Set Measuring-time. <num> =

FRUN ON Selects Free-Run FRUN OFF Selects Triggered mode TRIG OFF Selects Free-Run TRIG ON Selects Triggered mode TOUT <num> Sets Time-Out. <num> =

MEAC? Output the current Measurement

TOTM B

0.01 to 10 s. 0 = SINGLE

0.1 to 25.5 s. 0 = Time-Out OFF

control settings ***

Bus Related Commands

OUTM <number>

<number> High-speed

dump

0 OFF NORMAL ON 1 OFF SHORT ON 2 OFF NORMAL OFF 3 OFF SHORT OFF 4 ON FOR HIGH

MSR <num> Sets SRQ-mask, see ‘Service request’ EOI ON Selects EOI-mode ON. EOI OFF Selects EOI-mode OFF SPR <num> Select output separator, see ‘Output

separators’

X Device trigger, starts a new

measurement *** D Device clear, returns to default settings BUS? Output the current bus related settings *** ID? Output identity and which options are

installed ***

* Not available in LOCAL mode. ** Affect both inputs independent of INPA/INPB. *** This command must be placed at the end of a pro

gram message.

Output format

SPEED DUMP

MTCXO

compensation

OFF ***

5-13 Summary of Bus Commands

GPIB-interface Operation

Programming Examples

For HP-85 Controller

This program illustrate high measuring rate obtained with High-speed dump.

The actual measuring function is selected by the user in Lo cal-mode. When the program runs, two beep’s can be heard from the HP-85, Between these beep’s, the counter per forms 500 measurements and the result of each measure ment is transferred from the counter to the HP-85.

The output rate is approximately 125 readings/second in this example.

10 ! DEMO PROGRAM DUMP MODE 20 ! CNT-66 WITH HP85 AS 30 ! CONTROLLER 40 ! DUMP MODE WITH FREE RUN ON 50 CLEAR 60 DIM Z$[7508] ! BUFFER FOR 500

MEASUREMENTS WITH 15 BYTES 70 DIM B$[14] 80 IOBUFFER Z$ 90 LOCAL 710 100 DISP “SELECT FUNCTION IN LOCAL MODE!” 110 DISP “MEASURING TIME WILL BE” 120 DISP “SELECTED BY HP85 (SINGLE)!” 130 DISP “ANSWER Y WHEN READY TO START!” 140 INPUT A$ 150 IF A$<>"Y" THEN 130 160 DISP “MAKE 500 MEASUREMENTS” 170 OUTPUT 710 ;"TRIG OFF,MTIME 0,OUTM 4" 180 BEEP 190 E=TIME 200 TRANSFER 710 TO Z$ FHS ; COUNT 7500 210 F=TIME 220 TIME 230 DISP “READY! ELAPSED TIME:”;F-E;"s" 240 ! SHOW 5 RESULTS" 250 DISP “FIRST 5 RESULTS:” 260 FOR K=1 TO 5 270 ENTER Z$ ; B$ 280 ! GET FORMULA CHARACTER 290 F$=B$[1,1] 300 ! GET MULTIPLYER CHARACTER 310 M$=B$[2,2] 320 ! EVALUATE REGISTER 1 330 R1=0 340 FOR I=1 TO 8 350 S=NUM(B$[I,I])-48 360 IF S>=10 THEN S=S-7 370 R1=R1*16+S 380 NEXT I 390 ! EVALUATE REGISTER 2 400 R2=0 410 FOR I=9 TO 14 420 S=NUM(B$[I,I])-48 430 IF S>=10 THEN S=S-7 440 R1=R2*16+S 450 NEXT I 460 ! EVALUATE RESULT 470 IF F$="C" THEN R=10000000*R2/R1

480 IF F$="F" THEN R=R1*16^6+R2 490 IF F$="G" THEN R=R2/R1 500 IF F$="I" THEN R=.0000001*R1/R2 510 IF F$="J" THEN R=.0000001*(R1*16^6+R2) 520 IF F$="K" THEN R=.0000001*R2/R1 530 IF M$="H" THEN R=R*60 540 IF M$="L" THEN R=R*256 550 IF M$="N" THEN R=R/10 560 IF M$="O" THEN R=R*10

570 IF M$="P" THEN R=R*1 580 DISP B$,R 590 NEXT K 600 LOCAL 710 610 END

.Example of a result:

MEASURING TIME WILL BE SELECTED BY HP85 (SINGLE)! ANSWER Y WHEN READY TO START! ? Y MAKE 500 MEASUREMENTS READY! ELAPSED TIME: 3.927 S FIRST 5 RESULTS: JP000000000031 .0000049 JP000000000031 .0000049 JP000000000030 .0000048 JP000000000031 .0000049 JP000000000031 .0000049

.12751

5-14 Programming Examples

GPIB-interface Operation

For IBM PC with PM 2201

Example 1

The following example runs on an IBM compatible PC equipped with a PM 2201 GPIB interface. The installation and starting up of the PC program is not described, only the application program.

The program sets up the counter for 10 Period A measure ments and presents the average result on the screen.

100 ‘DEMO PROGRAM (NO 1) 110 ‘CNT-66 AND IBM PC 120 ‘WITH PM2201 GPIB INTERFACE 130 ‘AS CONTROLLER 140 CLS ‘CLEAR SCREEN 150 AD=7 ‘ADAPTOR NUMBER 160 ADDR=710 ‘COUNTER ADDRESS 170 SC=1 ‘SYSTEM CONTROLLER 180 RES$ = SPACE$(25) ‘RESULT 190 ACT = 0 ‘# READ CHARACTERS IN RES$ 200 MAX = 24 ‘MAX CHARACTERS TO READ IN RES$ 210 CALL IOINIT(AD,SC) ‘INIT INTERFACE 220 TIME=10 ‘TIMEOUT AFTER 10 SECONDS 230 CALL IOTIMEOUT (AD,TIME) ‘SET TIMEOUT 240 CALL IOCLEAR(ADDR) ‘SEND SDC 250 ‘SELECT PERIOD A, TRIGGERED MODE 260 ‘AND 1 S MEASURING-TIME 270 SEND$ = “PER A,TRIG ON,MTIME 1" 280 LENGTH=LEN(SEND$) 290 CALL IOOUTPUTS(ADDR,SEND$,LENGTH) 300 Z=0 310 ‘INPUT 10 SAMPLES 320 FORi=1TO10 330 CALL IOTRIGGER(ADDR) ‘TRIGGER COUNTER 340 CALL IOENTERS(ADDR,RES$,MAX,ACT) ‘READ

RESULT 350 Z=Z+VAL(MID$(RES$,8,13)) 360 NEXT I 370 PRINT “AVERAGE:”;Z/10;"S" 380 CALL IOLOCAL(ADDR) ‘GO TO LOCAL 390 END

Example of a result:

AVERAGE: 9.98004E–06 S OK

Example 2

This program example illustrates the ‘program data out’ fea ture of CNT-66. By asking a set of queries, the counter re sponds with its current setup. The output format of these answers to the queries is identical to the programming com mand format. The answers can be stored and used later for reprogramming (bus learn).

100 ‘DEMO PROGRAM 110 ‘CNT-66 AND IBM PC WITH PM2201 120 GPIB INTERFACE AS CONTROLLER 130 AD=7 ÁDAPTOR NUMBER 140 ADDR=710 ‘COUNTER ADDRESS 150 SC=1 ‘SYSTEM CONTROLLER 160 CALL IOINIT(AD,SC) ÍNIT INTERFACE 170 TIME=10 ‘TIMEOUT AFTER 10 SECONDS 180 CALL IOTIMEOUT(AD,TIME)

190 CLS ‘CLEAR SCREEN 200 ÁSK FOR AND PRINT PROGRAM DATA 210 PRINT “COUNTING SETTING:” 220 S$ = “FNC?” 230 GOSUB 520 240 A=1 250 GOSUB 550 260 S$ = “MEAC?” 270 GOSUB 520

280 A=2 290 GOSUB 550 300 S$ = “BUS?” 310 GOSUB 520 320 A=2 330 GOSUB 550 340 S$ = “INPA?” 350 PRINT “INPA:” 360 GOSUB 520 370 A=1 380 GOSUB 550 390 S$ = “INPB?” 400 PRINT “INPB:” 410 GOSUB 520 420 A=1 430 GOSUB 550 440 S$ = “ID?” 450 PRINT 460 PRINT “COUNTER TYPE:” 470 GOSUB 520 480 A=1 490 GOSUB 550 500 CALL IOLOCAL (ADDR) ‘GO TO LOCAL 510 END 520 L=LEN(S$) ‘LENGTH OF STRING TO SEND 530 CALL IOOUTPUTS(ADDR,S$,L) ÓUTPUT STRING 540 RETURN 550 FORI=1TOA 560 MAX=25 570 ACT=0 580 RES$=SPACE$(25) 590 CALL IOENTERS(ADDR,RES$,MAX,ACT) 600 B$ = LEFT$(RES$,ACT) 610 PRINT B$; 620 NEXT I 630 RETURN

Example of a result:

COUNTER SETTING: TIME A;B MTIME 1.00,FRUN ON

TOUT 00.0 MSR 000,OUTM 000 EIO OFF,SPR 010

INPA: TRGSLP NEG INPB: TRGSLP POS

COUNTER TYPE: PM6666/016/22 Ok

5-15 Programming Examples

GPIB-interface Operation

Example 3

This program prompts the user to input a programming se quence. The sequence is then sent to the CNT-66 and the corresponding measuring result is read.

100 ‘DEMO PROGRAM 110 ‘CNT-66 AND IBM PC WITH PM2201 120 ‘GPIB INTERFACE AS CONTROLLER 130 CLS ‘CLEAR SCREEN 140 AD=7 ‘ADAPTOR NUMBER 150 ADDR=710 ‘COUNTER ADDRESS 160 SC=1 ‘SYSTEM CONTROLLER 170 CALL IOINIT(AD,SC) ‘INIT INTERFACE 180 TIME=10 ‘TIMEOUT AFTER 10 SECONDS 190 CALL IOTIMEOUT (AD,TIME) 200 CALL IOCLEAR(ADDR) ‘SEND SDC 210 PRINT “INPUT YOUR PROGRAMMING

MESSAGE?” 220 PRINT “(TO QUIT THE PROGRAM, ANSWER *)” 230 LINE INPUT S$ 240 L=LEN(S$) ‘LENGTH OF STRING TO SEND 250 IF L<>1 GOTO 280 260 IF S$<>"*" GOTO 280 270 END 280 CALL IOOUTPUTS(ADDR,S$,L) ‘OUTPUT STRING 290 ‘TO BE SURE, TRIGGER COUNTER! 300 CALL IOTRIGGER(ADDR) 310 ‘GET THE MEASURING RESULT 320 MAX=25 330 ACT=0 340 RES$=SPACE$(25) 350 CALL IOENTERS(ADDR,RES$,MAX,ACT) 360 PRINT 370 PRINT “RESULT READ AS: ”;RES$ 380 PRINT 390 GOTO 210

Example of a result:

INPUT YOUR PROGRAMMING MESSAGE? (TO QUIT THE PROGRAM, ANSWER *) PER A,MTIME 0 RESULT READ AS: PER 0000001.00E–5

INPUT YOUR PROGRAMMING MESSAGE? (TO QUIT THE PROGRAM, ANSWER *)

For IBM PC with IBM GPIB

This example runs on an IBM PC with an ‘IBM General Pur

pose Interface Bus Adapter’ instead of the PM 2201 inter face.

The following set of device parameters is suitable for a CNT-66 with address 10. The device parameters are set with the configuration program ‘IBCONF’, see the IBM adapter manual.

Device Name: COUNTER

Send EOI w/last Byte of Write?

DESCRIPTION

Access Adapter Name?

Primary GPIB Address?

Secondary GPIB Address?

Timeout setting?

Terminate Read on EOS?

Send EOI with EOS byte?

Use 8-bit Compare on EOS?

Example 1

The following program sets up the counter for 10 Period A measurements and presents the average result on the screen.

100 ‘DEMO PROGRAM 110 ‘CNT-66 AND IBM PC WITH IBM 120 ‘GPIB ADAPTOR AS CONTROLLER 130 CLS ‘CLEAR SCREEN 140 ‘INIT 150 ADNAME$ = “COUNTER” 160 CALL IBFIND(ADNAME$,CNT%) 170 ‘SEND SDC 180 CALL IBCLR(CNT%) 190 ‘SELECT PERIOD A, TRIGGED MODE 200 ‘AND MEASURING TIME 1 S 210 WRT$ = “PER A,TRIG ON,MTIME 1" 220 CALL IBWRT (CNT%,WRT$) 230 ‘INPUT 10 SAMPLES 240 Z=0 250 FOR I= 1 TO 10 260 CALL IBTRG(CNT%) ‘TRIGGER COUNTER 270 CALL IBRD(CNT%,RD$) ‘READ RESULT STRING 280 Z=Z+VAL(MID$(RD$,8,13)) 290 NEXT I 300 PRINT “AVERAGE:”;Z/10;"S" 310 CALL IBLOC(CNT%) ‘GO TO LOCAL 320 END

.Example of a result:

AVERAGE: 9.980422E–06 S Ok

DEVICE PARAMETERS

NEW VALUE

EOS Byte?

VALID NAME

GPIB0

[GPIBx]

0AH

[0H to 1EH]

00H

[60H to 7EH; 0H disables]

T10s

[T10us to T1000s;TNONE disables]

0AH

[0H to FFH or '<character>]

Yes

[Yes or No]

Yes

[Yes or No]

Number: D 0

5-16 Programming Examples

Chapter 6

Performance Check

Performance check describes the measuring methods and data necessary to verify correct signal values and voltage levels in the counter. After completed “Performance Check” the counter will meet the specifications published in this manual.

MTCXO Oscillator

(Option 07)

Connect the external 10 MHz reference to input A.

–

Select measuring time 1.0 s.

–

The counter should display 10 MHz ±6 Hz. This is the

–

maximum deviation after one year due to aging and tem perature.

Preparations

Power up the instrument at least 30 minutes before check ing to let it attain normal operating temperature.

Equipment Required

Type Specifications

Adapter BNC - banana Adjustable power supply 4 V DC Attenuator BNC 20 dB T-piece BNC Feedthrough termination BNC 50 ohm /1W Delay cable BNC-BNC 10 ns (about 2 m RG-58) Digital multimeter 0-250 V AC, 0-10 V DC Frequency reference 10 MHz, accuracy 3*10 HF signal generator 1300 MHz LF synthesizer 2 MHz Oscilloscope 350 MHz Pulse generator 1 ms/250 ns Adjustment tool Insulated, for

trimmer potentiometers & trimmer capacitors

-8

Oscillator

To check the accuracy of the oscillator, use a reference with an accuracy of at least 3*10 Frequency Reference meets this requirement, if calibrated and properly adjusted.

Uncompensated Crystal Oscillator

–

Connect the external 10 MHz reference to input A.

–

Select measuring time 1.0 s.

–

The counter should display 10 MHz ±120 Hz. This is the maximum deviation after one year due to aging and tem perature.

-8

. The Pendulum 6688 OCXO

Input A and B

Where the procedures for input A and input B are similar, only input A is described.

Frequency MHz

Sensitivity and

Frequency Range

Connect the HF generator (via an attenuator if required)

–

to the BNC T-piece. Connect the T-piece to input A.

– Interconnect the T-piece with the 350 MHz oscilloscope.

Use as short a cable as possible.

–

Select measuring time 0.2 s.

–

Select function FREQ A.

–

Read the amplitude on the oscilloscope.

–

The instrument shall count correctly with the following sine wave input signals:

Common via A

–

Select RATIO A/B.

–

Switch on COM.

–

Connect the HF generator to input A.

–

Set the generator frequency to 12 MHz and the signal amplitude to 70 mVpp (-19 dBm).

–

The counter shall display 1.00000 ±1 in the last signifi cant digit (LSD); the LSD and the trigger indicator for in put B shall be visible.

–

Turn off COM.

Sine wave mVpp (dBm)

1 56 (-21) 30 56 (-21) 80 113 (-15)

120 113 (-15) 160 170 (-11)

6-2 Performance Check

Sensitivity and

Frequency Range in RATIO A/B

H F generator

50 ohm

Figure 6-1 Measurement setup.

Select RATIO A/B.

–

Connect the HF generator via the BNC T-piece to input A.

–

Connect the T-piece via a 50 ohm termination to input B.

–

Set the generator frequency to 12 MHz sine wave, and

–

the amplitude to 56 mVpp (-21 dBm).

The instrument shall now count and display 1.00000 ±1

–

in the LSD.

C ounter

50 ohm , to Input B

T-piece, to Input A

Performance Check

Set TRIGGER LEVEL to 1.00 V for both inputs.

–

Adjust the duration time from the pulse generator to give

–

a value of 0.1 ms on the counter display.

Select negative SLOPE A and positive SLOPE B.

–

The counter shall display 0.9 ms, ±1 in the last digit.

–

Average Time Interval A-B

Connect the Pulse Generator via the T-piece to input A.

–

Connect the T-piece via a 50 ohm termination and a

–

10 ns coaxial cable to input B.

Set the pulse repetition time to 50 µs.

–

Set the signal amplitude to 2 Vpp.

–

Set the pulse duration to 250 ns.

–

Set the rise and fall time to min.

–

Select positive SLOPE A and SLOPE B.

–

Pulse generator

50 ohm

C ounter

50 ohm , to Input B

T-piece, to Input A

10 ns

Trigger Level

– Connect the adjustable power supply and the multimeter

to input A using the BNC banana adapter.

–

Set the DC voltage to 4.00 V.

–

Select DC, AUTO LEVEL, READ LEVEL and COMMON.

–

The counter shall display “4.00 4.00", ± 0.2 V.

–

Move the DC voltage source to input B.

–

Turn off COMMON.

–

The counter shall display “0.00 4.00", ± 0.2 V.

Voltage Measurement

–

Disconnect all signal sources from both inputs.

–

Press RESET and select VOLT A.

–

Connect the LF synthesizer to input A.

–

Set the synthesizer to sine wave with an amplitude of

9.8 Vpp.

–

The counter shall display 4.9 V ±0.2 V and -4.9 V ±0.2 V at the following frequencies: 1 kHz, 10 kHz, 500 kHz, and 2 MHz.

Single Time Interval A-B

–

Connect the pulse generator to input A and input B.

–

Set the generator signal repetition time to 1 µs and the amplitude to 2 Vpp.

–

Set the rise and fall time to min.

–

Select TIME A-B and negative SLOPE B.

–

Select SINGLE measuring time.

Figure 6-2 Measurement setup for average

time interval A-B.

–

Select 0.2 s measuring time.

–

Select TIME A-B.

–

Select AC on both inputs.

–

Set SENSITIVITY to 0.02 V on both inputs.

–

The counter shall display 10 ns ±4 ns.

–

Select negative SLOPE A and SLOPE B. The counter readout shall not change by more than 2 ns.

–

Select positive SLOPE A and SLOPE B.

6-3 Performance Check

Performance Check

EXT REF Sensitivity

The “start counting” level shall be more than 1 dB below

–

the specified limit shown in the figure.

Repeat this procedure with the following frequencies:

–

100, 200, ... up to 1300 MHz

–

Signal source

Front

50 ohm

C ounter

T-piece, to Input A

R ear

50 ohm , to In p u t E X T R E F

Figure 6-3 Measurement setup for EXT

REF sensitivity.

Disconnect all signal sources from both inputs.

–

Select positive SLOPE A and SLOPE B.

–

Select FREQ A.

–

Fit a BNC T-piece to input A, and a 50 ohm termination to

–

the EXT REF input.

Connect a cable to the T-piece, and apply a 10 MHz

–

±0.1 MHz, 1.4 Vpp (7 dBm) sine wave signal.

Make sure that the EXT REF and TRIGGER A indicators

–

are visible.

The instrument shall now count and display 10 MHz.

–

HF Input

Let the HF Input be in use for at least 10 minutes before checking it.

GPIB Interface

(Option 04)

Type on the controller

REMOTE 710 The remote indicator should be

OUTPUT 710;"ID?"

ENTER 710;A$ Input result from the counter. DISP A$ The response on the display of

Figure 6-5 GPIB command sequence

The test is intended for an HP-85 controller.

Make sure that the TALK ONLY switch (the leftmost

–

switch in the address switch block) is set to “0".

Address the counter and execute the command se-

–

quence in the table below.

The counter will, if everything is correct, identify itself as:

PM6666/YZW/MN

where

This should happen

switched on. Ask for the counter identity.

the controller is the identity of the counter.

Sensitivity

3 dB

900

13001100

-1 5

-23.5

-2 7

dBm

S p e c ific a tio n lim it Start counting >1 dB

C orrect counting

Figure 6-4 HF Input - sensitivity and counting

levels.

–

Connect the sweep generator to the HF input.

–

Set the generator frequency to 70 MHz.

–

Decrease the amplitude from the generator until the in strument stops counting.

–

Increase the amplitude slowly until the instrument starts counting again. Read the value.

NOTE: Compensate for the losses in the coaxial cable when

reading the value (about 1 dB/m for RG/M58).

Y= 4 if the counter has an HF Input, else 0. Z= 3 for MTCXO, else 1. W= 6 (GPIB-bus is installed). M= Revision No. of counter firmware. N= Revision No. of GPIB-bus firmware.

6-4 Performance Check

Chapter 7

Calibration and Adjustment

Calibration

To maintain the performance of the timer/counter, we rec ommend that you calibrate the timebase of your instrument every year, or more often if you require greater timebase ac curacy. Calibration should be performed with traceable ref erences and instruments at a certified calibration laboratory. Contact your local service center for calibration.

To know the present status of your instrument, test your counter from time to time. The test can be made according to the information in Chapter 6, “Performance Check”.

Oscillators

The frequency of the reference crystal oscillator is the main parameter that influences accuracy of a counter. External conditions, such as ambient temperature and supply volt age, influence the frequency, but aging is also a factor. When adjusting, you compensate the reference crystal os cillator only for deviation in frequency due to aging.

Some Important Points:

The high-stability oscillator option 07 uses mathematical compensation of the displayed result, based on measured actual ambient temperature. Each MTCXO has a stored table of frequency deviations per degree C. The actual oscillator frequency varies with temperature, but the deviations are known and compensated for.

How often should you calibrate?

In the table below you can see the uncertainty of your time base oscillator for various MTBRC (Mean Time Between Recalibration) intervals.

Compare the requirements of your application with the val ues in the table, and select the proper MTBRC accordingly.

Please note that the frequency uncertainty when operating in a temperature controlled environment is different from field use. See the two sections in the table.

When adjusted, keep in mind that the ref

erence crystal oscillator will be compen sated only for frequency deviation caused by aging.

–

The frequency uncertainty for standard oscillators is mainly dependent on the ambient temperature. Variations in ambient temperature between 0 and 50 °C may cause a frequency change of up to 100 Hz, whereas the aging per month is only 5 Hz. When operating, there is al ways a temperature increase inside the counter that will influence the oscillator.

Option Standard Option 07

Timebase type UCXO MTCXO

Total uncertainty, for operating temperature 0°C to 50°C, @ 2s (95 %) confidence interval:

-1 month after calibration

-3 months after calibration

-1 year after calibration

-2 years after calibration Typical total uncertainty, for operating

temperature 20°C to 26°C, @ 2s (95 %) confidence interval:

-1 month after calibration

-3 months after calibration

-1 year after calibration

-2 years after calibration

<1.2 x 10 <1.2 x 10 <1.2 x 10 <1.5 x 10

<4x10 <4x10 <7x10

<1.2 x 10

-5

-6

-5

<3x10 <4x10 <6x10 <1x10

<2x10 <4x10 <6x10 <1x10

-7

-6

-7

-6

For complete specifications see chapter 9 (Specifications)

7-2 Calibration

Timebase References

This chapter describes adjustment procedures which may need to be performed occasionally, and which must be per formed after repair.

Removing the Cover

WARNING: When you remove the cover you will ex

pose live parts and accessible terminals which can be dangerous to life.

Loosen the tw o screw s using a Pozidrive N o. 1 screw driver

Figure 7-1 Loosen These Screws to Remove

Cover.

–

Make sure that the power cable is disconnected.

Calibration and Adjustment

Set the oscillator frequency to 10 MHz ±10 Hz by adjust

–

ing the trimmer capacitor C403 from the solder side of the oscillator board. Use the specified screwdriver.

MTCXO (Option 07)

The optional MTCXO Time-base can easily be calibrated and adjusted without using tools.

Preparations

If you remove the cover when the counter has been

switched on, the temperature of the MTCXO will rapidly drop about 10°C. Since the MTCXO must have a stable temperature when calibrating you must wait an hour be tween removing the cover and calibrating.

If the counter has been switched off more than three hours, you can calibrate it directly.

Calibration and Adjustment Procedure

Remove the cover see preceding paragraph.

–

Allow the MTCXO to reach the new ambient temperature.

–

(See ‘Preparations’.)

Connect the 10 MHz reference to Input-A.

–

Switch ON the counter.

–

Adjust the sensitivity control so that the counter counts

–

properly.

Hold down the CALIB-button, on the main printed-circuit

–

board in the counter, and press the Reset-button.

WARNING: Although the power switch is in the off

position, the line voltage is present on the printed circuit board.

–

Loosen the two screws in the rear feet.

–

Grip around the front panel and gently pull the Timer/Counter out of the cover.

Equipment

For required test equipment, see Performance Check.

Frequency Reference

The Pendulum 6688 frequency standard or the option 40 oven-enclosed oscillator available in some Pendulum counters meet the requirement, if calibrated within the last 12 months.

Checking Accuracy

Uncompensated Crystal Oscillator

–

Power up the instrument at least 30 minutes before checking to let it attain normal operating temperature.

–

Connect the external 10 MHz reference to input A.

C A L IB -b u tto n

Figure 7-2 Location of the CALIB-Button

–

Wait about 20 seconds, until the display shows

10.0000000 MHz. Now the oscillator is calibrated.

–

Switch OFF the counter and disconnect the 10 MHz ref erence.

–

Fit the cover.

The MTCXO is now adjusted to a relative uncertainty of

where U Uc= relative uncertainty of calibration.

+UU

= resolution uncertainty = 2*10

-8

7-3 Timebase References

Calibration and Adjustment

This page is intentionally left blank.

7-4 Timebase References

Chapter 8

Specifications

Measuring Functions

Frequency A or C

(frequency B via GPIB/IEEE-488 only)

Range

Freq A: 0. 1 Hz to 160 MHz (1 20 MHz to 160

MHz with limited temperature range; typical +23°C ±5°C)

Freq B: 0. 1 Hz to 16 MHz (via GPIB/ IEEE-488

only)

Freq C: 70 MHz to 1.3 GHz Mode: Reciprocal frequency counting

LSD Displayed:

25 10

Period A

Range: 8 ns to 2*108s Mode: Single period measurement

(SINGLE) or average period measurement (at 0.2s, ls or 10s measuring times)

LSD Displayed: SINGLE period measurement:

100 100

Average period measurement:

. ´´-FREQ

measuring time

ns Time s

PERIOD

25 10

. ´´-PERIOD

()

Time s

()

measuring time

100

LSD Displayed (Ratio B/A):

25.

meas time FREQ B´

(0.2, 1, or 10 s measuring time)

LSD Displayed (Ratio A/B Single, and Ratio B/A Single):

110

RATIO

LSD Displayed (Ratio C/A or C/B):

640

meas time FREQ A or B´

Time Interval A/B

(time interval B-A via GPIB/IEEE-488 only)

Range: 100 ns to 2*10

20s (average)

Mode: Single time interval (SINGLE) for time

interval measurements (at 0.2s, 1s or 10s measuring times)

LSD Displayed: SINGLE time interval measurement:

100 100

ns Time s

TIME

Average time interval measurements:

25 10

. ´-s

Averaged Number of Intervals N:

measuring time/pulse repetition time

Note: Input signals must be repetitive and asynchronous

with respect to the time base

s (SINGLE); 0 ns to

()

100

Time s

()

Ratio A/B

(ratio B/A, C/A or C/B via GPIB/IEEE-488 only)

–7

Range: 1*10

Frequency Range Input A: 0 MHz to 160 MHz (A/B); 0 MHz to

Input B: 0 MHz to 16 MHz Input C: 70 MHz to 1.3 GHz

LSD Displayed (Ratio A/B)

to 2*109(A/B);

–8

1*10

to 2*108(B/A); 0 to 1*10 B/A SINGLE); 8 to 6*10

(A/B SINGLE and

(C/A, C/B)

16 MHz (B/A, C/A, A/B SINGLE) (120 MHz to 160 MHz with limited temperature range; typical +23°C ±5°C)

meas time FREQ B´

(0.2, 1, or 10 s measuring times)

Min Dead Time from Stop to Start:

250 ns

Timing Difference A-B Channels:

4nsmax

Totalize A

(totalize B via GPIB/ IEEE-488 only)

Range: 0 to 1*10

(kilopulses or Megapulses) the result is truncated if out of display range

Frequency Range: 0Hzto12MHz Pulse Pair Resolution: 80 ns LSD Displayed: 1 unit count (counts <10

(counts ³109)

Gated by B (A) Mode:

Event counting on input A (B) during the duration of a pulse on input B (A)

Start/Stop by B (A) Mode:

Event counting on input A (B) between two consecutive pulses on input B (A)

with indication of k or M

); 5*counts/10

8-2 Measuring Functions

Specifications

Manual Mode:

Event counting is controlled by the START/STOP button. Sequential start-stop counts are accumulated. RESET closes the gate and resets the timer/counter to zero.

Volt Max/Min A

(Volt max/min B via GPIB/IEEE-488 only)

Range: –51V to +51V Frequency Range:

DC and 100 Hz to 50 MHz (input A); dc and 100 Hz to 5 MHz (input B)

Resolution: Input signals within ± 5V, 20 mV; input

signals outside ±5V, 200 mV

Uncertainty DC and 100 Hz to 12 MHz (A), or to 1MHz (B):

Input signals within ±5V, 30 mV±1%of reading ± 3% of Vp-p; input signals outside ± 5V, 300 mV ± 3% of reading ±3% of Vp-p

Uncertainty 12 MHz to 50 MHz (A) or 1MHz to 5 MHz (B):

Input signals within ± 5V, 30 mV ± 10% of reading ± 10% of Vp-p; input signals outside ± 5V, 300 mV ± 10% of reacting ± 10% of Vp-p

Input-A and Input-B

to 60 mVrms typ., 120 MHz to 160 MHz (at room temp.)

Attenuation: xl or x10, switch selectable or AUTO

Trigger Slopes: Positive or negative

Trigger Level Range DC-Coupled: –51V to +51V, adjustable via up/down

control

AC-Coupled: 0V fixed or AUTO level

Trigger Level Resolution:

20 mV, signals within ± 5V; 200 mV, signals outside ± 5V

Trigger Level Setting Accuracy:

±10mV ±1% of setting

AUTO Trigger Level:

Trigger Level on input A (and B when required) is automatically set to 50% of input signal amplitude.

Frequency Range:

100 Hz to 160 MHz (120 MHz to 160 MHz with limited temperature range; typical +23°C ± 5°C)

Sensitivity: 150 mVpp

Trigger Indicators:

Tri-state LED indicators; On: Signal above set trigger level. Off: Signal below set trigger level. Blinking: Triggering occurs.

Frequency Range DC-Coupled: DC to 160 MHz (120 MHz to 160 MHz

with limited temperature range; typical +23°C ±5°C)

AC-Coupled: 20 Hz to 160 MHz (120 MHz to 160 MHz

with limited temperature range; typical +23°C ±5°C)

Minimum Pulse Duration:

4ns

Coupling: AC or DC Impedance: 1MW//35 pF Channel Input: Separate A and B, or common via A Maximum Voltage Without Damage:

350V (dc + ac peak) between 0Hz and 440 Hz, falling to 8V rms at 1MHz

Sensitivity, DC-Coupled Sine: 20 mVrms, 0Hz to 30 MHz; 40 mVrms,

30 MHz to 120 MHz, 60 mVrms typ., 120 MHz to 160 MHz (at room temp.)

Pulse: 60 mVp-p, 0Hz to 30 MHz; 110 mVp-p,

30 Hz to 120 MHz; sensitivity decreases to 60 mVrms at 160 MHz typically

Sensitivity, AC-Coupled Sensitivity is selectable in 6 steps:

20 mV, 50 mV, 100 mV, 200 mV, 500 mV and 1Vrms (sine) nominal

Maximum Sensitivity:

20 mVrms, 20 Hz to 30 MHz; 40 mVrms, 30 MHz to 120 MHz; sensitivity decreases

Input Channel Selection:

Separate A and B, or A and B common via input-A.

Input C

Frequency Range: 70 MHz to 1.3 GHz Coupling: AC Operating Input Voltage Range:

10 mVrms to 12Vrms, 70 MHz to 900 MHz; 15 mVrms to 12Vrms, 900 MHz to 1100 MHz; 40 mVrms to 12Vrms, 1100 MHz to 1300 MHz

AM Tolerance: 94% at max 100 kHz modulation

frequency; minimum signal must exceed minimum operating input voltage requirement

Input Impedance: 50W nominal, VSWR :1 Max Voltage Without Damage:

12V rms, overload protection with pin diodes

External Reference Input D

Input Frequency:10 MHz ± 0.1 MHz Coupling: AC Sensitivity: 500 mV rms Input Impedance:Approx 300W at 10 MHz Maximum Input Voltage:

15Vrms

8-3 Input-A and Input-B

Specifications

Auxiliary Functions

Power On/Off

Switches counter power on/off. At power up a self-test is made and the counter is set to default settings.

Default Settings

Function: FREQ A Measuring-Time: 0.2 s Coupling: AC on Input-A, DC on Input-B Trigger level: Auto Trigger slope: Positive on A and B.

RESET

The RESET button has three functions:

RESET: Starts a new measurement. The settings

are not changed.

LOCAL: Makes the counter go to LOCAL operation,

when in remote operation (unless Local Lock-Out is programmed).

START/STOP: Opens/closes the gate in TOTALIZE A,

manual mode.

Measuring Time

A measuring time of 0.2s, 1s, 10s or SINGLE can be selected

NOTE: When SINGLE is selected together with PERIOD,

RATIO or TIME, the result is a single cycle meas-urement, but SINGLE together with FREQUEN-CY results in a fixed 3 ms Measuring-time.

Definitions

LSD Displayed

LSD = unit value of the least significant digit displayed. All calculated LSDs (see Measuring Functions section) should be rounded to the nearest decade (e.g., 0.3 Hz is rounded to 0.1 Hz and 5 Hz to 10 Hz) and cannot exceed the 9th digit.

Resolution

Resolution = smallest increment between two measuring re sults on the display, due to the ±1 count uncertainty.

Freq A, Freq C, Period A

Resolution can be 1 LSD or 2 LSD if:

LSD measuring time

FREQ or PERIOD

the resolution is 2 LSD units (30% probability). Otherwise resolution is 1 LSD unit (70% probability).

Ratio A/B:

Resolution can be 1 LSD or 2 LSD. If:

LSD measuring time

RATIO FREQ A

the resolution is 2 LSD units (30% probability). Otherwise resolution is I LSD unit (70% probability).

SINGLE Period A and SINGLE Ratio A/B:

Resolution equals 1 LSD unit

-107

Measuring rate: Approx. 5 measurements/s. Approx. 2

measurements/s when AUTO trigger level is switched on.

Display time: Normally the display time equals the set

Measuring-time. When SINGLE is selected, a display time of 0.1 seconds is used.

Display Hold

The current measuring result is frozen on the display. A new measurement starts when the RESET button is pressed.

Time A-B: Resolution (95% confidence level) equals

1 LSD unit or 100 nsÖN, whichever is greater

Total uncertainty

The relative total uncertainty, depends on the following fac tors:

FREQ PERIOD RATIO or TIME

relative trigger un

relative timebase uncertainty U

relativ

The total uncertainty (K=2) is calculated as:

UU U

resolution

certainty U

e systematic uncertainty U

22 2

rns

8-4 Auxiliary Functions

Specifications

Relative Trigger Uncertainty

Freq A, Period A:

noise voltage A Vp p

signal slope A V s meas time

Ratio A/B:

noise voltage B Vp p

signal slope B V s meas time

Totalize A, Gated or Start/Stop by B:

noise voltage B Vp p

signal slope B V s gate time B

Time A-B:

noise voltage A Vp p

signal slope A V s TIME N

noise v

signal slope B V s TIME N

Relative Time Base Uncertainty:

deviation from 10 MHz

10 MHz

()

oltage B Vp p

()-´´

The relative time base uncertainty Utb depends on the following factors:

= initial uncertainty

= freq. Uncertainty due to temperature variation

= ageing

222

ita

UUU

See table “Time Base”.

Relative Time A-B Systematic Uncertainty:

Inaccuracy caused by timing difference between A and B channels <±4 ns/TIME

()

´´

()

General Specifications

Power Requirements

Line Voltage: 115V or 230Vrms ± 15%; 45 Hz to

440 Hz; 20 VA CNT-66 including all options

Safety: Compliant to CE:

EN 61010-1 (1990) + A1 (1992) Cat II

EMC: Compliant to CE:

EN 55011 (1991) Group 1, Class B EN 50082-1 (1992)

Display Readout: 9-digit LCD with unit and cursor indication

Unit Indication: MHz, kHz, Hz, mHz, ks, s, ms, s, ns, M, k,

m, m and n.

GATE Indicator: Indicates that the counter is measuring

REMOTE Indicator:

Indicates when the counter is remotely controlled via an installed GPIB/IEEE-488 interface (option 04)

Cursor: Indicates selected measuring function,

se-lected Measuring-time, input triggering, display hold and whether an external reference frequency is in use.

Time Base (Crystal oscillator)

CNT-66

Time base Standard Option 07

Time base type UCXO MTCXO

Uncertainty due to:

- Calibration adj. Tolerance,

-Ageing: per 24h

- Temp. Variations:

- Power voltage variation: ± 10% <1x10

Power-on stability:

- Deviations versus final value after 24hr on time, after warm-up time of:

Total uncertainty, for operating tem perature 0°C to 50°C, at 2s (95%) confidence interval:

-1 year after calibration

-2 years after calibration

Typical total uncertainty, for operat ing temperature 20°C to 26°C, at 2s (95%) confidence interval:

-1 year after calibration

-2 years after calibration

at +23°C ± 3°C <1x10

per month per year

0°C-50°C, 20°C-26°C (typ. values)

n.a. <5x10 <5x10

<1x10 <3x10

n.a.

30 min

<1.2x10 <1.5x10

<7x10

<1.2x10

-6

-7

-6

-5

-6

-8

-5

-6

-5

<1x10

n.a. <1x10 <5x10

<2x10 <5x10

<1x10

n.a.

30 min

<6x10 <1x10

-7

-8

-9

-7

-6

-7

-6

8-5 General Specifications

Specifications

Environmental Data

Temperature Operating: 0°C to + 50° Storage: –40°C to +70°

Altitude Operating: 5000m (53.3 kN/m Storage: 15,000m (15.2 kN/m

Humidity Operating: 10% to 90% RH, no condensation Storage: 5% to 95% RH

Vibration Test: According to IEC 68Fc

Bump Test: According to IEC 68Eb

Handling Test: According to IEC 68Ec

)

Mechanical Data

Size: 186mmW*88mmH*270mmL(7.3 in

W * 3.5 in H * 10.6 in L)

Weight: 2.1 kg (4.6 Ib)

Optional Accessories

GPIB/IEEE-488 Interface, Option 04

Mounting: Inside counter cabinet

InterfaceFunctions:

SH1, AH1, T5, L4, SR1, RL1,DC1, DT1, E2

Address Setting:Switch selectable at rear panel be-tween

0 and 30. Factory preset at 10.

Programmable Device Functions:

Measuring functions Measuring-time Trig level offset selection Trigger slope Manual Totalize gate control Output separator selection Device clear Device trigger High-speed dump MTCXO on/off Short output format Free run/Triggered measurements Set SRQ-mask Program data out queries Device identity query

Output Format

Function code 3 to 6 characters

Normally space. O on overflow

Measuring result

Exponent pointer Exponent sign (+ or -) Exponent value 0 to 9 Selected separator

Second separator LF only if output separator CR+LF has been selected

FFFFFFOXXXXXXXXXXE±XS(S) 21(22) characters.

When you select ’Short output format’ FFFFFF and lea-ding zeroes are omitted.

Output Data Separator:

Default separator at power-on is LF. The separator can be programmed to be any non printable ASCII-code with decimal equivalent 0-31, except 27 (ESC). In addition the combination 13+10 (CR+LF) can be pro-grammed. The EOI-line can be programmed to be active together with the last output byte sent.

Input Separator: The counter accepts the following

characters as separators: ETX, ETB, CR, LF, ’ ’(space) ’,’(comma), ’:’(colon) ’;’(semicolon).

High-Speed Dump:

The contents of the counting registers are transferred to the controller, without being processed by the counter. The processing must be done in the controller instead.

The output format is FMXXXXXXXXXXXXS(S) where F is calculation formula, M is multiplier, X..X = 12 hex-digits rep resenting the register contents, and S(S) is the set out-put separator.

Ranges: Same as for normal operation, with the

following exceptions:

Frequency: Max measuring time: 1 s Period, average: Max measuring time: 1.4 s Time interval, average; 0 ns to 1.6 s:

Max measuring time:4 s Ratio A/B: 0 and 6*10 Ratio B/A: 0 and 6*10–8to 1.6*10 Ratio C/A, C/B: 8 to 4*10

–7

to 1.6*10

Programming Code Format:

7-bit ISO code (ASCII) characters. Both upper and lower case char-acters are accepted.

8-6 Environmental Data

Max Data Output Rate Normal Mode: Approx 5 readings/s High-Speed Dump:

Approx 100 readings/s. The highest output rate is obtained at SINGLE measuring time.

Output Time for Measuring Data Normal Mode: Approx 9 ms (20 bytes) High-Speed Mode:

Approx 4 ms (1 5 bytes)

Response Time for Addressing:

Approx 600 ms

Response Time for Trigger Command (GET): Normal operation: Approx. 10 ms High-speed dump: Approx. 2 ms

Response Time for Serial Poll:

Approx. 1.5 ms

Specifications

Ordering Information

Models

CNT-66 Timer/Counter

Included with the Instrument

Line cord, operator manual, and Calibration certificate.

Reference Oscillator Option

Option 07 MTCXO Timebase

Interface Option

Option 04 GPIB/IEEE-488

Input Buffer Size: 28 bytes

Typical Read Time for Programming Data:

Approx 1ms/byte (unless input buffer is full)

Rack Mounting Adapter, Option 06

The option 06 is a 19" wide Rack Mounting Adapter. It can host one CNT-66 or CNT-69 Counter only.

High stability time-base, Option 07

See specifications for optional MTCXO time-base.

Carrying Case, Option 09

The option 09 is a leather-like carrying case, for protection of the counter during transportation.

Optional Accessories

Option 06 Rack mount kit

Option 09 Carrying case

8-7 Ordering Information

Specifications

This page is intentionally left blank.

8-8 Ordering Information

Chapter 9

Appendix

Checking the Sensitivity of Counters

Introduction

The sensitivity of a counter is normally specified as the minimum signal voltage on which the input of the counter will trigger correctly.

When you use a signal-source with an output-impedance of 50W, constant-output-amplitude, and the counter has a 50W input-impedance, the input signal of the counter is in theory independent of the cable length. However, if the input im pedance deviates from 50W there will be standing wave re flections which will cause changes in the amplitude of the signal between the signal-source and the counter input.

Two factors determine the magnitude of the changes, i.e. frequency and capacitive load.

EXAMPLE: Fora1MW//35 pF input, the 35 pF parallel

capacitance is approximately equal to a 50W ca pacitive load at 100 MHz.

Consequently, it is of the utmost importance to know how sensitivity is measured.

Preparations

Connect the instruments as illustrated in the figure above. Turn off AUTO and set the counter to maximum sensitivity.

Method 1

Adjust the amplitude of the signal-source to the minimum

–

level accepted by the counter.

Read the amplitude on the oscilloscope.

–

Check that the reading is the same as, or less than, the

–

sensitivity level in the counter specifications.

Method 2

Adjust the amplitude of the signal-source until the oscillo

–

scope indicates the sensitivity limit in the counter specifi cations.

Check that the counter is operating correctly.

–

Low Impedance Inputs (50W)

If You Have a Calibrated Signal Source

Adjust the signal-source to the sensitivity limit of the

–

counter.

Connect it directly to the input of the counter.

–

Check that the counter is operating correctly.

–

Recommended Instruments

–

Signal-source with a 50W output impedance.

–

>350 MHz oscilloscope with a 50W input impedance.

–

BNC T-piece.

–

Two BNC-cables, one short and one long.

High Impedance Inputs (1 MW)

Counter under test

Signal source

50 ohm

Attenuator (if required)

T-piece directly on counter

Figure 9-1 GPIB connector and address

switch, the numbers above the switches indicate the significance of each switch.

O s c illo s c o p e >350 M H z

50 ohm

Shortest cable possible

If You Don’t Have a Calibrated Signal Source

Use either of the following methods

Method 1

–

Connect the output of the signal-source directly to the input of the counter.

–

Turn off AUTO and Set the counter to maximum sensitivity (if adjustable).

–

Adjust the amplitude of the signal-source to the minimum level accepted by the counter.

–

Disconnect the cable from the counter and connect it to the oscilloscope.

–

Read the amplitude on the oscilloscope.

–

Check that the reading is the same as, or less than, the sensitivity level in the counter specifications.

Method 2

–

Connect the signal-source to the oscilloscope.

–

Adjust the output amplitude of the signal-source until the oscilloscope indicates the sensitivity limit in the counter specifications.

–

Disconnect the cable from the oscilloscope and connect it to the counter.

–

Turn off AUTO and set the counter to maximum sensitiv ity (if adjustable).

–

Check that the counter is operating correctly.

9-2 Checking the Sensitivity of Counters

These procedures ensure unambiguous measurements of the signal voltage at the input of the counter.

Chapter 10

Service

Sales and Service office

For additional product information, customer support and service, please contact Pendulum Instru ments AB at the following address:

Pendulum Instruments AB

Box 20020

SE-161 02 Bromma

Sweden

Visit address:

Karlsbodavägen 39, Bromma

Phone: +46 (0)8 5985 1000

Fax: +46 (0)8 5985 1040

Email: info@pendulum.se

Web Site: www.pendulum.se

GUARANTEE STATEMENT

Service

This guarantee is in addition to all rights which the buyer may have against his supplier under the sales agreement be tween the buyer and the supplier and according to local legislation.

Pendulum Instruments AB guarantees this product to be free from defects in material and workmanship under normal use and service for a period of eighteen (18) months from the date of shipment. This guarantee does not cover possible re quired re-calibration actions and/or standard maintenance actions. This guarantee extends only to the original end pur chaser and does not apply to fuses, batteries, power adapters, or to any product or part thereof that has been misused, al tered, or has been subjected to abnormal conditions of operation and handling. Pendulum Instruments’ obligation under this guarantee is limited to repair or replace a product that is returned to the factory within the guarantee period, provided that Pendulum Instruments determines that the product is defective and that the failure has not been caused by misuse, alteration or abnormal operation. If a failure occurs, send the product, transportation prepaid, to

Pendulum Instruments AB

Adolfsbergsvägen 2

SE- 168 66 Bromma Sweden

with a description of the malfunction. At Pendulum Instruments’ option, repairs will be made or the product replaced. Pen dulum Instruments shall return the repaired or replaced product to the Buyer, transportation prepaid. However, the Buyer shall pay all shipping charges, duties and taxes for products returned to Pendulum Instruments from another country. Pen dulum Instruments assumes no risk for damage in transit.

Disclaimer

The foregoing guarantee is exclusive and is in lieu of all other guarantees, expressed or implied, including but not limited to any implied guarantee of merchantability, fitness, or adequacy for any particular purpose or use. We shall not be liable for any direct, indirect, special, incidental, or consequential damages, whether based on contract, tort, or otherwise.

III

Service

This page is intentionally left blank.

Chapter 11

Index

Abnormal bit

SEE Status byte

Selecting.................................4-10

AC coupling selection buttons.

Location ..................................2-3

Address .....................................5-3

Adjustments

timebase..................................7-2

Attenuator

From GPIB ................................5-6

Operating ................................4-10

x1......................................4-10

x10.....................................4-10

Attenuator buttons

Location ..................................2-3

Auto level button

Location ..................................2-3

Auto On/Off

GPIB code ...............................4-10

Selection.................................4-10

Bus commands

Summary ...........................5-12 - 5-13

Bus drivers ...................................5-2

Bus learn

GPIB....................................5-11

Calibration ...................................7-2

Caution statements ............................1-2

Check list

GPIB program .............................5-4

Checking

GPIB communication ........................5-3

COM B via A button

Location ..................................2-3

Common

From GPIB ................................5-7

GPIB code ...............................4-12

Operation ................................4-12

Control function ...............................5-2

Controller

Connecting GPIB ...........................5-3

Controls

operation .................................4-2

Coupling

From GPIB ................................5-6

GPIB code ...............................4-10

Selecting.................................4-10

Cover removal ................................7-3

Crystal oscillators

calibration .................................7-2

Selecting.................................4-10

Delimiters

SEE Separators

Device clear ..................................5-2

Device Trigger ................................5-2

Display hold

Operating the button.........................4-8

Display-hold button

Location ..................................2-3

Earthing

SEE Grounding

EOI mode

SEE Output separator

Error codes ..............................4-3,4-14

External reference

Connection ................................3-3

Description of function ......................4-13

Location of connector ........................2-2

External reference input

Connection ...............................4-12

Free run

From GPIB ................................5-7

Frequency A

From GPIB ................................5-5

GPIB code ................................4-2

Frequency B

From GPIB ................................5-6

Selecting..................................4-2

Index

Frequency C

GPIB code ................................4-4

Selecting..................................4-4

Function selection

GPIB.....................................5-5

Function-selector button

Location ..................................2-3

Get

SEE Triggered

GPIB address-selector

Location ..................................2-2

GPIB interface-connector

Location ..................................2-2

GPIB-Interface operation ...................5-1-5-16

High speed dump

GPIB....................................5-10

Hold

display ...................................4-8

HP controller

GPIB example ............................5-14

IBM GPIB

GPIB example ............................5-16

ID?

GPIB.....................................5-3

Identity of the counter ........................5-3

Input separator

GPIB.....................................5-4

Input A ......................................6-2

Operation .................................4-8

Input B ......................................6-2

Operation .................................4-8

Input C

Operation ................................4-12

Input settings

From GPIB ................................5-6

Input-A BNC-connector

Location ..................................2-3

Input-B BNC-connector

Location ..................................2-3

Input-C BNC-connector

Location ..................................2-3

Listener function...............................5-2

Local .......................................4-8

DC coupling selection buttons ....................2-3

Measuring

Frequency A ...............................4-2

Frequency C...............................4-4

Period....................................4-4

Ratio A/B .................................4-4

Time interval A-B ...........................4-4

Time selection .............................4-6

Totalize ...................................4-4

Voltage...................................4-6

Measuring time

From GPIB ................................5-6

Measuring-time selector-button

Location ..................................2-3

MTCXO

Calibration ................................7-3

Normal output format

GPIB....................................5-10

Operating the controls ..........................4-2

Oscillators

calibration .................................7-2

Output separator

GPIB.....................................5-5

Output mode

GPIB ...............................5-9-5-10

Period

From GPIB ................................5-5

Period A

Selecting..................................4-4

PM 2201

GPIB example ............................5-15

Power switch

Operating .................................4-2

Power switch

Location ..................................2-3

Power-inlet socket

Location of ................................2-2

Programming check-list .........................5-4

LCD-display

Location ..................................2-3

Queries

GPIB....................................5-12

III

Index

Rack mount adapter

installation ................................3-3

Rack Shelf ...................................3-3

Ratio A/B

GPIB code ................................4-4

Selecting..................................4-4

Read level ..................................4-12

Read level

GPIB code ...............................4-12

Read level button

Location ..................................2-3

Rear feet ....................................2-2

Remote/local .................................5-2

Removing the cover ............................7-3

Reset

Description of function .......................4-9

Operating the button.........................4-8

Reset button

Location ..................................2-3

Safety.......................................1-2

Screws for removing the cover....................2-2

Selecting function

via GPIB ..................................5-6

Sensitivity

From GPIB ................................5-6

GPIB code ...............................4-10

Separators

Input .....................................5-4

Output ...................................5-5

Service request ...............................5-2

GPIB.....................................5-8

Set value

Operation ................................4-10

Set value button

Location ..................................2-3

Short output format

GPIB....................................5-10

Slope

From GPIB ................................5-6

GPIB code ...............................4-10

Operation ................................4-10

Slope selection buttons

Location ..................................2-3

Start/Stop Totalize

Operation .................................4-8

Start/Stop totalize

From GPIB ................................5-7

Starting a new measurement

SEE Reset

Status byte

GPIB.....................................5-8

Symbols .....................................1-2

Talk only switch ...............................5-3

Talker function ................................5-2

Tilting support.................................2-3

Time interval A/B

From GPIB ................................5-5

Time interval A-B

GPIB code ................................4-4

Selecting..................................4-4

Time out

GPIB.....................................5-7

Timebase

calibration .................................7-2

Totalize A

From GPIB ................................5-5

GPIB code ................................4-4

Selecting..................................4-4

Trigger indicators

Location ..................................2-3

Trigger level

From GPIB ................................5-7

GPIB code ...............................4-10

Triggered mode

From GPIB ................................5-7

Unpacking ...................................3-2

Warning statements ............................1-2

Volt max/min

Selecting..................................4-6

Voltage-range

Location of ................................2-2

Selecting..................................3-2

Pendulum CNT-66 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Safety Instructions

Product Presentation

Installation

Operating Instructions

GPIB-interface Operation

Performance Check

Calibration and Adjustment

Specifications

Appendix

Service

Index