Microtest 6375, 6376, 6377, 6378, 6379 User Manual

LCR METER

6375 / 6376 /

6377 / 6378/ 6379

1.0

User Manual

CONTENTS

1. SAFETY ............................................................................................................................. 1–1

1.1 General ........................................................................................................................... 1–1

1.2 AC Power Supply .......................................................................................................... 1–1

1.3 Adjustment, Maintenance and Repair ............................................................................ 1–2

1.4 Static Electricity ............................................................................................................ 1–2

2. INTRODUCTION.............................................................................................................. 2–1

3. INSTALLATION ............................................................................................................... 3–1

3.1 AC Line Connections .................................................................................................... 3–1

3.2 Measurement Connections ............................................................................................. 3–1

4. OPERATION ..................................................................................................................... 4–1

4.1 The Rear Panel ............................................................................................................... 4–1

4.1.1 Voltage Selector ...................................................................................................... 4–1

4.1.2 IEC Socket and Fuse Holder ................................................................................... 4–1

4.1.3 Rear Panel Control Connections............................................................................. 4–2

4.1.4 DC 5V Out .............................................................................................................. 4–2

4.1.5 GPIB Connector ...................................................................................................... 4–2

4.1.6 Switching the Instrument ON .................................................................................. 4–3

4.1.7 Switching the Instrument OFF ................................................................................ 4–3

4.2 The Front Panel ............................................................................................................. 4–4

4.2.1 The Soft Keys.......................................................................................................... 4–4

4.2.2 The Navigation Keys ............................................................................................... 4–5

4.2.3 The Control Keys .................................................................................................... 4–5

4.2.4 The Data Entry Keypad ........................................................................................... 4–6

4.3 Trimming........................................................................................................................ 4–8

4.3.1 Performing an O/C Trim or S/C Trim.. ................................................................... 4–9

4.4 Measuring a Component .............................................................................................. 4–10

4.4.1 Example ................................................................................................................ 4–11

4.4.2 MEASUREMENT MODE Parameters ................................................................. 4–12

5. ADVANCED OPERATION ............................................................................................. 5–1

5.1 Two-, Three- and Four-Terminal Connections ............................................................... 5–1

5.2 Measurement of Very Small Capacitors......................................................................... 5–1

5.3 Measurement of Very Small Inductors ........................................................................... 5–1

5.4 Measurement of Iron-Cored and Ferrite Inductors ......................................................... 5–2

5.5 MULTI STEP MODE .................................................................................................... 5–3

5.5.1 MULTI STEP – Set ................................................................................................. 5–3

5.5.2 MULTI STEP – Run ............................................................................................... 5–4

5.6 The STATUS Page ......................................................................................................... 5–5

5.6.1 The STATUS Page Parameters ................................................................................ 5–5

6. GENERAL PURPOSE INTERFACE BUS (GPIB) ...................................................... 6–1

6.1 GPIB Control ................................................................................................................. 6–1

6.1.1 Introduction ............................................................................................................. 6–1

6.1.2 Interface Specification............................................................................................. 6–1

6.1.3 Changing GPIB Address ......................................................................................... 6–1

6.1.4 Message Syntax....................................................................................................... 6–2

6.1.5 Data Output ............................................................................................................. 6–5

6.1.6 Status Reporting...................................................................................................... 6–6

6.1.7 Common Commands ............................................................................................. 6–11

6.1.8 Standard Operation Status Commands .................................................................. 6–12

6.2 6375 Series Device-Specific Commands...................................................................... 6–13

6.2.1 Command Summary .............................................................................................. 6–13

6.3 Example Programs ....................................................................................................... 6–37

6.3.1 Example 1 ............................................................................................................. 6–38

6.3.2 Example 2 ............................................................................................................. 6–39

6.3.3 Example 3 ............................................................................................................. 6–39

6.3.4 Example 4 ............................................................................................................. 6–41

7. 6375 SERIES SPECIFICATION ..................................................................................... 7–1

7.1 Measurement Parameters................................................................................................ 7–1

7.2 Test Conditions .............................................................................................................. 7–1

7.2.1 AC Drive ................................................................................................................. 7–1

7.3 Measurement Speeds...................................................................................................... 7–2

7.4 Display Range ................................................................................................................ 7–3

7.5 Modes Of Operation ...................................................................................................... 7–3

7.5.1 MEASUREMENT .................................................................................................. 7–3

7.5.2 MULTI-STEP .......................................................................................................... 7–3

7.6 Measurement Connections ............................................................................................. 7–3

7.7 Measurement Accuracy .................................................................................................. 7–3

7.8 Accuracy Chart............................................................................................................... 7–5

7.8.1 |Z| Accuracy Chart ................................................................................................... 7–5

7.8.2 |Z| vs L, C Chart ...................................................................................................... 7–6

7.8.3 |Z|, |Y|, L, C, R, X, G and B Accuracy ..................................................................... 7–7

7.8.4 D Accuracy .............................................................................................................. 7–7

7.8.5 Q Accuracy .............................................................................................................. 7–7

7.9 General ........................................................................................................................... 7–9

7.9.1 Power Supply .......................................................................................................... 7–9

7.9.2 Display .................................................................................................................... 7–9

7.9.3 Remote Control ....................................................................................................... 7–9

7.9.4 Remote Trigger ........................................................................................................ 7–9

7.9.5 Mechanical .............................................................................................................. 7–9

7.10 Environmental Conditions ........................................................................................... 7–9

7.10.1 Temperature Range................................................................................................ 7–9

7.10.2 Relative Humidity ................................................................................................. 7–9

7.10.3 Altitude ............................................................................................................... 7–10

7.10.4 Installation Category ........................................................................................... 7–10

7.10.5 Pollution Degree ................................................................................................. 7–10

7.10.6 Safety .................................................................................................................. 7–10

7.10.7 EMC.................................................................................................................... 7–10

8. THEORY REFERENCE .................................................................................................. 8–1

8.1 Abbreviations ................................................................................................................. 8–1

8.2 Formulae ........................................................................................................................ 8–1

8.3 Series/Parallel Conversions ........................................................................................... 8–2

8.4 Polar Derivations ........................................................................................................... 8–2

9. MAINTENANCE, SUPPORT AND SERVICES ........................................................... 9–1

9.1 Guarantee ....................................................................................................................... 9–1

9.2 Maintenance................................................................................................................... 9–1

9.2.1 Cleaning .................................................................................................................. 9–1

9.2.2 Safety Checks ......................................................................................................... 9–1

9.3 Support and Service ....................................................................................................... 9–2

1–1

OPERATOR

Person operating equipment for its intended purpose.

Note: The OPERATOR should have received training
appropriate for this purpose.

RESPONSIBLE BODY

Individual or group responsible for the use and maintenance
of equipment and for ensuring that operators are adequately
trained.

WIRE

EUROPEAN

N. AMERICAN

LIVE

BROWN

BLACK

NEUTRAL

BLUE

WHITE

GROUND

GREEN/YELLOW

GREEN

1. SAFETY

1.1 General

This equipment has been designed to meet the requirements of EN61010-1 ‘Safety requirements
for electrical equipment for measurement, control & laboratory use’ and has left the factory in a
safe condition.

The following definitions in EN61010-1 are applicable:

The RESPONSIBLE BODY must ensure that this equipment is only used in the manner
specified. If it is not used in such a manner, the protection provided by the equipment may be
impaired.

This product is not intended for use in atmospheres which are explosive, corrosive or adversely
polluted (e.g. containing conductive or excessive dust). It is not intended for use in safety
critical or medical applications.

The equipment can cause hazards if not used in accordance with these instructions. Read them
carefully and follow them in all respects.

Do not use the equipment if it is damaged. In such circumstances the equipment must be
made inoperative and secured against any unintentional operation.

Microtest and the associated sales organizations accept no responsibility for personal or
material damage, nor for any consequential damage that results from irresponsible or
unspecified operation or misuse of this equipment.

1.2 AC Power Supply

Power cable and connector requirements vary between countries. Always use a cable that
conforms to local regulations, terminated in an IEC320 connector at the instrument end.

If it is necessary to fit a suitable AC power plug to the power cable, the user must observe the
following colour codes:

1–2

The user must also ensure that the protective ground lead would be the last to break should the
cable be subject to excessive strain.

If the plug is fused, a 3-amp fuse should be fitted.
If the power cable electrical connection to the AC power plug is through screw terminals then,

to ensure reliable connections, any solder tinning of the cable wires must be removed before
fitting the plug.

Before switching on the equipment, ensure that it is set to the voltage of the local AC power
supply.

WARNING!

Any interruption of the protective ground conductor inside or outside the equipment or
disconnection of the protective ground terminal is likely to make the equipment
dangerous. Intentional interruption is prohibited.

1.3 Adjustment, Maintenance and Repair

WARNING!

The equipment must be disconnected from all voltage sources before it is opened for any
adjustment, replacement, maintenance, or repair.

When the equipment is connected to the local AC power supply, internal terminals may be live
and the opening of the covers or removal of parts (except those to which access can be gained
by hand) is likely to expose live parts.

Capacitors inside the equipment may still be charged even if the equipment has been
disconnected from all voltage sources.

Any adjustment, maintenance, or repair of the opened equipment under voltage must be carried
out by a skilled person who is aware of the hazards involved.

Service personnel should be trained against unexpected hazards.
Ensure that only fuses with the required rated current and of the specified type are used for

replacement. The use of makeshift fuses and short-circuiting of fuse holders is prohibited.

1.4 Static Electricity

The unit supplied uses static-sensitive devices. Service personnel should be alerted to
components which require handling precautions to avoid damage by static electrical discharge.

Before handling circuit board assemblies containing these components, personnel should
observe the following precautions:

1–3

1) The work surface should be a conductive grounded mat.

2) Soldering irons must be grounded and tools must be in contact with a conductive surface to

ground when not in use.

3) Any person handling static-sensitive parts must wear a wrist strap which provides a leaky

path to ground, impedance not greater than 1M.

4) Components or circuit board assemblies must be stored in or on conductive foam or mat

while work is in progress.

5) New components should be kept in the suppliers packaging until required for use.

2–1

2. INTRODUCTION

The 6375 Series LCR Meter provide 4-terminal (Kelvin) measurement of passive components
over the frequency range 20Hz to 100kHz (6375) or 200kHz (6376) or 20Hz to 500KHz(6377)
or 20Hz to 1MHz(6378) or 20Hz to 10MHz(6379) for AC measurements, the measurement
drive level can be varied from 10mV to 2V rms.

The meter’s measurement, display and control facilities include:

 spot frequency measurements
 multi-step measurements at a number of user-defined steps
 display of actual measurement values
 display of measurement results in absolute terms or as the percentage difference from a

specified nominal value

 bar graph analogue display for easy adjustment of variable components—spot frequency

measurements only

All the above functions can be selected via manual front panel control or remote control via the
GPIB interface for fully-automated high-speed testing.

3–1

WIRE

EUROPEAN

N. AMERICAN

LIVE

BROWN

BLACK

NEUTRAL

BLUE

WHITE

GROUND

GREEN/YELLOW

GREEN

250V

3A–T

3. INSTALLATION

3.1 AC Line Connections

The unit is provided with a power cable capable of carrying the input current for both 115V and
230V operation. This cable should be connected via a suitable connector to the local AC power
supply. The colour code employed is as follows:

The supply voltage setting can be checked by looking through the transparent window on the
rear panel next to the power inlet socket. This can be changed by first disconnecting the unit
from the electrical supply, removing the window and adjusting the switch to read the required
voltage. Replace the window and ensure that the fuse rating is correct:

No adjustment is required for variation of supply frequency.
Before connecting the AC power, read the precautions listed under section 1.2—AC Power

Supply.
The instrument is not suitable for battery operation.
The power switch is located on the left of the front panel.

3.2 Measurement Connections

The 6375 Series can be used with any of the following Microtest leads, fixtures or adaptors.

Kelvin Clip Leads (Fine Jaws), Part No. 1EVA40100

General purpose 4-terminal measuring leads for conventional components giving good accuracy
except for measurement of very small capacitances or very small inductances where the use of
the 4-terminal component fixture, part number 1EV1006, will give more accurate results.

Kelvin Clip Leads ((large jaws), Part No. 1EVA40180

Similar to part number 1EVA40100 but with larger jaws making them more suitable for
connection to terminal posts or larger diameter component leads.

3–2

Four-Terminal Lead Set, Part No. 1EV1505

600mm screened cable terminated in four crocodile clips at the component end. Not
recommended for use above 30 kHz.

SMD Tweezers, Part No. 1EVA40120

2-terminal component tweezers for use with surface-mount or leadless components. A cam is
incorporated to set the jaw spacing to the width of the component to be tested so that O/C trim
will trim out the residual capacitance of the tweezers.

Four-Terminal Component Fixture, Part No. 1EV1006

Remote fixture with sliding jaws to accommodate both axial and radial leaded components.
This fixture will give the greatest accuracy for 4-terminal measurements of conventional
components. The jaws can be set to the component width for trimming and component
measurements can be performed without moving the measuring leads: stable lead positioning is
important when measuring low value inductors.

1100 Protection Unit, Part No. 1J1100

The standard protection built into the 6375 Series prevents damage to the instrument when
charged capacitors are connected to the measurement terminals with energy levels up to 0.25J
and a maximum voltage of 500V.

The 1100 Protection Unit fits between the measurement terminals and the DUT to raise the
maximum energy level to 25J and the voltage to 1000V.

Other Test Leads

Other test leads can be used with the meter, provided that they conform to the following
connection protocol.

The four front-panel BNC sockets are for screened cable connections to the unknown
component or test fixture: use good quality 50Ω screened cable, e.g. RG174A/U; cable length
should not exceed 2m. In each case, the outer connection provides the screening and the inner is
the active connection. The outer pair of panel connectors carry the signal source (YELLOW)
and the current return (BROWN) signals. The innermost pair serve to monitor the actual voltage
at the device under test (DUT), excluding any voltage drops arising in the source and return
leads. The common ground point should be connected to component guards and/or screens for
in-circuit measurements.

The outers of the four BNC sockets are not directly connected inside the meter, but it is
important that the GROUNDS are linked OUTSIDE. For accurate high frequency operation, the
leads must be screened and the screens connected close to the DUT.

3–3

Figure 3-1 4-Terminal Measurement

4–1

4. OPERATION

WARNING!

This equipment is intended for use by suitably trained and competent persons.

This product can cause hazards if it is not used in accordance with these instructions.
Read them carefully and follow them in all respects. Double check connections to the unit
before use.

DO NOT USE THIS EQUIPMENT IF IT IS DAMAGED.

4.1 The Rear Panel

Figure 4-1 The 6375 Series Rear Panel

4.1.1 Voltage Selector

The instrument can be operated from an AC power source of either 115V or 230V. Before
applying AC power to the IEC socket, ensure that the voltage selector switch is set to the
voltage of the local AC power supply.

4.1.2 IEC Socket and Fuse Holder

Please read section 1.2 before connecting the IEC socket to the AC power source.

4–2

Label

Type

Use

Reference

GPIB

Standard GPIB

For remote operation.

Sections 4.1.6 and 6

DC 5V out

Stereo phone jack

1. Duplicates action of
front panel trigger
key.

2. DC 5V output

Section 4.1.4

RS-232

9-way D-type (male)

Reserved

PRINTER Port

25-way D-type (female)

Reserved

Handler

RJ45 connector

OPTIONAL - to
interface to PASS /FAIL
signal

4.1.3 Rear Panel Control Connections

4.1.4 DC 5V Out

4.1.4.1 External Trigger (A-B)

The duplicates the action of the front panel trigger key. The input is TTL compatible and when
logic low is equivalent to operating the front panel trigger key. This input is level sensitive and
fully debounced, and includes a pull up resistor to enable shorted contacts such as relays or
footswitches to be used.

4.1.4.2 DC 5V Output (A-C)

Output DC 5V for user’s applications (max. current 1.5A)

Figure 4-2 the contact assignment of the phone jack

4.1.5 GPIB Connector

The General Purpose Interface Bus (GPIB) is a parallel port which allows communication
between the instrument and other devices such as PCs fitted with a suitable interface card. The
GPIB port allows remote control of the instrument for measurement of components and the
collection of measurement results. For details of GPIB control and commands see section 6.

Devices should be connected to the instrument using a standard GPIB 24-pin connector
assembly with a shielded cable. Use of the standard connector consisting of a plug and

4–3

Pin

Description

Pin

Description

1

Data Line 1

13

Data Line 5

2

Data Line 2

14

Data Line 6

3

Data Line 3

15

Data Line 7

4

Data Line 4

16

Data Line 8

5

EOI (End or Identify)

17

REN (Remote Enable)

6

DAV (Data Valid)

18

Ground

7

NRFD (Not Ready For Data)

19

Ground

8

NDAC (Not Data Accepted)

20

Ground

9

IFC (Interface Clear)

21

Ground

10

SRQ (Service Request)

22

Ground

11

ATN (Attention)

23

Ground

12

Screen

24

Signal Ground

receptacle is recommended and should be compatible with the Amphenol and Cinch Series 57
or Amp Champ.

4.1.5.1 GPIB Connector Pin Assignment

4.1.6 Switching the Instrument ON

With the instrument connected to the correct AC power supply (see section 3—Installation)
press the POWER switch. The instrument will display the mode and settings selected when the
instrument was last switched off.

If the display is too bright or too dark, use the CONTRAST control above the power switch to
set the contrast level.

If the meter had previously been set up for measuring components, testing can recommence after
checking the settings.

To return to the MAIN MENU press the Menu control key.

4.1.7 Switching the Instrument OFF

The power can be switched OFF at any time without damage to the instrument, but to avoid
losing trim and calibration data, the instrument should be switched OFF when it is in a
quiescent state rather than when it is running a routine, e.g. trimming, calibration or data entry.

4–4

4.2 The Front Panel

Figure 4-2 The6375 Series Front Panel

4.2.1 The Soft Keys

The general protocol is that soft keys labelled with UPPER CASE letters select the labelled
mode and soft keys labelled with lower case letters select settings within the current mode.

The functions of the ten soft keys change according to the mode selected. For example, when
the MAIN MENU is displayed by pressing the Menu key, the soft keys relate to the various
modes available, e.g. MEASURE, STATUS, etc. Once a mode has been selected, the soft keys
labelled with small letters select settings within the mode, while the soft keys labelled with
capital letters select the labelled modes.

4–5

Figure 4-3 The Soft Keys

4.2.2 The Navigation Keys

Figure 4-4 The Navigation Keys

When the set up details are showing on the screen (in some modes, there is a soft key which
toggles between Hide Setup and Show Setup: this soft key can be seen in Figure 4-3), the left

and right navigation keys, and , allow each parameter to be selected in turn. When a
parameter is selected, the up and down navigation keys, and , step the numeric value for
AC level and frequency: the steps vary according to the value but are always multiples of 1, 2 or

5. Finer frequency steps can be achieved by using the data entry keypad, see section 4.2.4 For
other parameters, the and navigation keys change the settings, Auto Range/ [fixed range],
Slow/Med/Fast/Max.

4.2.3 The Control Keys

Figure 4-5 The Control Keys

4–6

Figure 4-6 Single Shot Mode

Figure 4-7 Repetitive Mode

Pressing Local restores control to the front panel when the instrument is under GPIB control.

Figure -The 6375 Series Main Menu

Sngl/Rep toggles between Single shot mode and Repetitive mode. When Sngl/Rep is pressed
the display briefly indicates the mode selected as shown in Figure 4-6 and Figure 4-7 below.
Single shot mode is also indicated by the lack of a continuously flashing asterisk (*) in the top
left corner of the screen. Conversely, the presence of a continuously flashing asterisk indicates
that the instrument is in repetitive mode. The asterisk flashes once every time the instrument
makes a measurement.

When in single shot mode, the Trigger key initiates a single measurement.

4.2.4 The Data Entry Keypad

Figure 4-8 The Data Entry Keypad

4–7

MEASURE

Code

Description

10

Select fine frequency steps

11

Select coarse frequency steps

80

Hide V.I value in measurement mode

81

Show V.I value in measurement mode

The data-entry keypad is a multi-function key set permitting manual entry of data values,
measurement units and control codes.

The Units key must be used prior to keying a unit or multiplier. Where more than one unit is
available on a key, e.g. D/Q or V/A, pressing the key will display the first unit, pressing the key
again will display the second unit. Terminate the units mode with Enter to accept the key

sequence. Pressing Clear will delete the whole key sequence; pressing will delete the last
key press.

An invalid keypad entry will cause the entry line to be cleared and an error message, such as the
one shown in Figure 4-9, to be displayed. The existing settings will be preserved.

Figure 4-9 Example of an Error Message from an Invalid Keypad Entry

The +/- key may be used before or after a value to change its sign. If the key is pressed more
than once, the value will toggle between + and -. For numbers which are positive only, this key
is disabled.

4.2.4.1 Keypad Codes

A number of special functions are available by pressing Code followed by a valid code number
and terminated with Enter. The codes shown below are only available in the mode or menu
indicated.

4–8

Key Sequence Examples (characters in [ ])

Example 1: Supply the meter with a value of 27.39mH

1) Select the following settings in MEASUREMENT MODE:

AC Meas, L, Q, Parallel, Show Scale, %.

2) Using the and keys, highlight the nominal parameter (underneath the left-hand-side of

the scale).

3) Key the following sequence:

[.] [0] [2] [7] [3] [9] [Units] [H] check data entry line is correct, then press [Enter]

or

[2] [7] [.] [3] [9] [Units] [m] [H] [Enter]

If a mistake is made in a key sequence, before pressing Enter, press to delete the last key
press or Clear to delete the whole key sequence.

Example 2: Set the frequency to 100 kHz

1) Using the and keys, highlight the selected frequency.

2) Key the following sequence:

[1] [0] [0] [0] [0] [0] [Enter]

or

[1] [0] [0] [Units] [k] [Enter]

or

[.] [1] [Units] [M] [Enter

4.3 Trimming

The purpose of trimming is to eliminate the effects of stray capacitance or series impedance in
the connecting leads or fixture.

The trim values are held in non-volatile memory and for most measurements no retrimming is
necessary. The exceptions are when the lead set or fixture is changed; when the highest possible
accuracy is required for measurements of very high or very low impedances.

Depending on the trim option selected, the meter trims by making measurements at a number of
frequencies, including the measurement frequency in use when the trim was initiated, and
storing the corrections for each. If the measurement frequency is changed the meter
automatically applies a new correction value by interpolation of the stored values.

For O/C Trim the Kelvin clips or fixture jaws should be separated by a distance equivalent to
the DUT pin separation.

4–9

Figure 4-10 Connections for O/C trimming of Kelvin clips

Figure 4-11 Connections for S/C trimming of Kelvin clips

For S/C Trim the connector jaws should be clipped to a piece of wire or a component lead as
close together as possible. Do not connect the clips directly together: this does not provide the
necessary 4-terminal short circuit and will lead to trim errors.

4.3.1 Performing an O/C Trim or S/C Trim..

1) Select CALIBRATE, either from the MAIN MENU, or from a mode which has

CALIBRATE as an option (in which case pressing the RETURN soft key will return the

meter to the original mode). The meter will enter CALIBRATE MODE.

2) Select O/C Trim or S/C Trim

3) Open- or short-circuit the Kelvin clips or fixture jaws as appropriate.

4) Select the trim option required and wait until the meter has finished trimming. The trim

options are described below.

Figure 4-12 6375 Series Calibrate Mode

4–10

4.3.1.1 Trim Options.

Figure 4-13 Trim Options

All freq trims at a number of frequencies, including the frequency set when the trim was
initiated. For most measurements made using standard test leads and fixtures this is the normal
trim option to use. The other trim options are normally only used in exceptional circumstances,
such as when a special test fixture fails O/C or S/C trim at certain frequencies outside of the
component test parameters.

Spot trim trims only at the frequency set in MEASUREMENT MODE.
<= 10 kHz trims at a number of frequencies up to and including 10 kHz.
<= 100 kHz trims at a number of frequencies up to and including 100 kHz.
Abort cancels the trim and displays the CALIBRATE MODE main screen.

Note:

If, after trimming with an option other than All freq, a measurement frequency is selected which
is outside of the trim parameters, or will be displayed
at the top of the screen and no trim corrections will be applied for the frequency selected. The
meter can be used without trim correction but full measurement accuracy will not be available
until the meter is retrimmed using an option which covers the new measurement frequency.

4.4 Measuring a Component

The meter should be powered up with the test leads or fixture connected to the front panel BNC
connectors. If the test leads or fixture have been changed since the meter was last used, they
should be trimmed as described in section 4.3.

The following instructions illustrate the process of measuring a component.

1) Press the front panel Menu control key. The MAIN MENU will be displayed.

2) Press the MEASURE soft key. MEASUREMENT MODE

4–11

Figure 4-14 Will be displayed.

3) Use the soft keys, shown in Figure 4-2 and Figure 4-3, to set the required measurement

parameters: these are described in section 4.4.2 below. Do not exceed the limitations of the
component to be measured.

4) Connect the component to be measured to the test leads or fixture.

5) If the meter is in Repetitive mode, the measured values will be displayed and updated

according to the Speed setting selected. A continuously flashing asterisk (*) in the top left­hand-corner of the screen indicates that the meter is in repetitive mode.

6) If the meter is in Single shot mode, the front panel Trigger key must be pressed to initiate

a measurement; alternatively, a suitable trigger pulse may be applied to the DC5ＶOut
socket on the rear panel, see section4.1.4. When in single shot mode, the asterisk (*) in the

top left-hand-corner of the screen only flashes when a measurement is triggered.

4.4.1 Example

This example will take the user through the process of measuring the capacitance and
dissipation factor of a 470nF capacitor. The settings used are examples only and the user may
substitute other settings, subject to the limitations of the component to be measured.

The meter should be powered up with the test leads or fixture connected to the front panel BNC
connectors. If the test leads or fixture have been changed since the meter was last used, they
should be trimmed as described in section 4.3.

1) Press the front panel Menu control key. The MAIN MENU will be displayed.

2) Press the MEASURE soft key. MEASUREMENT MODE will be displayed.

3) Ensure that the meter is in Repetitive mode (if there is no continuously flashing asterisk (*)

in the top left-hand-corner of the screen press the front panel Sngl/Rep control key—the
meter will briefly indicate which mode it is entering (shown in Figure 4-6 and Figure 4-7)).

4) Use the soft keys to select the following parameters. Pressing the soft keys will either

toggle between two options or, where more than two options are available, scroll through
the options from left to right, one option at a time.

4–12

Rdc Meas

DC measurement of resistors. The only measurement options are DC drive
level, range and speed.

AC Meas

Allows AC measurements to be performed at the selected drive level and
frequency. The measurement terms and equivalent circuit are set with the
next three soft keys.

AC Meas
C
D
Parallel

5) Using the navigation keys, highlight and set each of the following parameters in turn. Use

the and navigation keys to highlight a parameter and the and navigation keys to
alter the highlighted parameter setting. Settings may be altered one step at a time, or
continuously by holding the navigation key down.

500mVac

1.5000 kHz
Range Auto
Speed Med

6) Connect the component to be measured to the test leads or fixture. The screen will display

the measured values of C and D. The display should be similar to Figure 4-15

Figure 4-15 Example Capacitance and Dissipation Factor

4.4.2 MEASUREMENT MODE Parameters

The following MEASUREMENT MODE parameters are selectable with the ten soft keys to
the right of the display.

4–13

C L X B Z Y

The first measurement term.
To select X, the Parallel/Series soft key must first be set to Series.
To select B, the Parallel/Series soft key must first be set to Parallel.
When either Z or Y are selected, the second measurement term is angle ( º ).

The Q D R G and Parallel/Series soft keys are not appropriate and are
therefore not shown.

Q D R G

The second measurement term.
To select G, the Parallel/Series soft key must first be set to Parallel.

Parallel/Series

Parallel or Series equivalent circuit. All first and second measurement

terms are shown above this soft key but only the appropriate measurement
terms can be set depending on whether Parallel or Series is selected. See
the narrative on C L X B Z Y and Q D R G (above) for details.

Show/Hide Scale

Toggles between Show Scale and Hide Scale. The selection either shows a
diagram of the equivalent circuit, i.e. Parallel or Series, or shows a bar
graph representation of either of the measurement terms (selectable by
setting the nominal and limits, see Abs % below). The bar graph scale can
either be used as a quick visual verification that the component is within the
limits set, or can be used for adjustment of variable components. When the
measurement falls within the centre band the meter reports ; when
the measurement falls above or below the centre band the meter reports

or .

Abs %

Only available when the bar graph scale is displayed. Toggles between Abs
and %. When Abs is selected, absolute Hi and Lo limits (i.e. units of the
measured parameter) are displayed. When % is selected, a nominal value
together with Hi and Lo percentage limits are displayed.

The limits and nominal value (if applicable) must be set using the and
navigation keys to highlight each parameter and the data entry keypad to set
each value (the use of the data entry keypad is described in section 4.2.4).
When in % mode, the bar graph scale Hi and Lo limits can easily be set
equidistant about the nominal by setting either of the limits then
highlighting the other limit and pressing the keypad Enter key twice. This
mimics the setting of the other limit but with the opposite sign

Save Nom

Only available when the bar graph scale is displayed and % limits is
selected. If a standard component exists, it can be connected to the test
leads or fixture and measured by the meter. Pressing Save Nom enters the
most recent meter measurement of the component as the nominal test value
for comparing all subsequent components with.

Notes:

1) To change this function from the first to the second measured parameter

(or vice versa), first enter a dummy value with units via the keypad; e.g.
to change from L to R, enter [1] [units] [Ω] [Enter] then press the Save

4–14

Nom key.

2) Do not use the Save Nom function if the measured value is negative

(e.g. an inductor measured above its self resonant frequency).

Show/Hide
Setup

Once the measurement parameters have been set, Hide Setup can be
selected to clear them from the screen. The parameter settings are still valid
and will be used for component measurements. The bar graph scale and
limits will still be displayed. Hide Setup is used primarily to unclutter the
display, making it more easily readable. Selecting Show Setup will
redisplay the parameter settings.

CALIBRATE

Enters CALIBRATE MODE which is used for Trimming (section 4.3) .

Drive Level

Set by highlighting the parameter with the and navigation keys, then
altering the setting in pre-determined steps with the and navigation
keys, or by using the data entry keypad. The range is:

Rdc Meas mode
AC Meas mode

10mV or 2V
Variable between: 10mV–2V
At frequencies above 5MHz the maximum

values are restricted (see specification).

The following MEASUREMENT MODE parameters are those displayed in the bottom left­hand-corner of the screen, shown in figure 4-16, They are only visible when Hide Setup is NOT
SELECTED.

Figure4-16 Non-Soft Key MEASUREMENT MODE Parameters

4–15

Measurement
Frequency

Set by highlighting the parameter with the and navigation keys, then
altering the setting in pre-determined steps with the and navigation
keys, or by finer increments using the data entry keypad. The range is:

20Hz to 200KHz (6375)
20Hz to 500KHz (6376)
20Hz to 1MHz (6377)
20Hz to 5MHz (6378)

20Hz to 10MHz (6379)

Range

Toggles between auto range and manual range selection, set by highlighting
the parameter with the and navigation keys and altering the setting

with the and navigation keys. Auto range automatically selects the
most accurate range for the measurement. Circumstances where manual
ranging may be more appropriate include:

 measuring non-linear components (auto range may hunt)
 to avoid the short auto range delay, for example when using max speed

with an auto handler.

The manual range is set using the data entry keypad. Ranges 1 to 7 are
valid.

Speed

Four measurement speeds are available: Slow, Med, Fast and Max.
Selecting slower measurement speeds increases the display resolution and
decreases measurement noise by averaging. The measurement speed is set

by highlighting the parameter with the and navigation keys and altering
the setting with the and navigation keys.

For detail description of measurement speed, refer to chapter 6­specification.

5–1

5. ADVANCED OPERATION

This section will provide the user with a guide to:

 two-, three- and four-terminal connections
 measurement of very small capacitors
 measurement of very small inductors
 measurement of iron-cored and ferrite inductors

5.1 Two-, Three- and Four-Terminal Connections

The meter has four front panel BNC sockets for screened cable connections to the device under
test (DUT). In each case the outer connection provides the screening and the inner is the active
connection. The outer pair of panel connectors carries the signal source (YELLOW) and current
return (BROWN) signals, while the inner pair serves to monitor the actual voltage at the DUT,
excluding any voltage drops arising in the source and return leads. With Kelvin clip leads or the
four-terminal component fixture 1EV1006, screened four-terminal connections are made
automatically to the DUT.

If the impedance being measured is greater than 1kΩ, four-terminal connections are not
necessary, the S/C trim facility being used to remove the effect of series lead impedance.

For low impedances, the main advantage of four-terminal connections is to reduce the effect of
contact resistance variations at the DUT.

If the DUT has a large area of metal not connected to either of its measured terminals (e.g. a
screen or core), this should be separately connected to ground using the green clip lead; but if
there is a relatively large unscreened conducting surface which is connected to one of its
measured terminals (e.g. an air-spaced tuning capacitor), this should be connected to the
YELLOW signal source lead to minimize noise pick-up.

5.2 Measurement of Very Small Capacitors

For best accuracy when measuring small value capacitors it is necessary to perform an O/C trim
(see section 4.3.1) at the frequency to be used for the measurement and to ensure that the
measurement leads are not moved between the trimming and the measurement.

When measuring surface-mount or leadless capacitors with the two-terminal SMD tweezers,
part no. 1EVA40120, the cam should be used to set the jaw spacing of the tweezers to the width
of the DUT when performing the O/C trim so that the residual capacitance of the tweezers is
trimmed out.

5.3 Measurement of Very Small Inductors

The meter measures the difference between the inductance of S/C trimming and the inductance
of the DUT. Stable measurement lead arrangements are essential for low inductance
measurements; the use of the four-terminal component fixture, part no. 1EV1006, is
recommended for leaded components. When using this fixture, S/C trim (see section 4.3.1) is
achieved by placing a wire across the jaws:

5–2

a 5cm length of 1mm diameter wire has an inductance of 50nH
a 5cm length of 2mm diameter wire has an inductance of 40nH

The known inductance of the wire used for the S/C trim should be subtracted from the
measured DUT inductance.

A similar, stable fixture arrangement should be used for four-terminal measurements of surface­mount or leadless components: contact the Microtest Applications Department if this kind of
fixture is required.

The Q is always low, but self-capacitance is not normally a problem at the meter’s measurement
frequencies. Where possible, make the measurements at the same AC level as the level used
during trimming.

When an inductor is measured at a frequency much lower than that for which it is designed (e.g.
an HF choke tested at AF) it will tend to behave as an inductive resistor. In these circumstances,
the inductance measurement accuracy is widened by the factor (1 + 1/Q).

Air-cored coils are particularly susceptible to noise pick up and should be kept well clear of any
test equipment that may contain power transformers or display scan circuitry. Also avoid
proximity to metal objects which may modify inductor characteristics.

5.4 Measurement of Iron-Cored and Ferrite Inductors

The effective value of iron-cored and ferrite inductors can vary widely with the magnetization,
and therefore the level, of the test signal. Ideally, they should be measured at the AC level and
frequency of use. When core materials can be damaged by excessive magnetization (for example,
some tape heads and microphone transformers), check before connection that the test signal
level is acceptable.

The meter is not designed to pass DC through inductors: if this facility is required please
contact the Microtest Applications Department; the Microtest Precision Magnetics meter
PMA3260A is designed specifically for this type of measurement, and when used with one or
more 3265A 25A Bias Units, up to 125A DC is available.

5–3

Copy

The Copy soft key will duplicate the current step to the next.

Delete

The Delete soft key will delete the current step.

LOAD

Recall the program which is existed in the non-volatile memory.

Save

Save the current settings to non-volatile memory. Up to 64 programs can
be stored in the meter.

Save as

Save the current settings to non-volatile memory with a new name.

New

Create a new program under a new name.

Run

Enter MULTI STEP- Run mode.

Dly

Trigger delay time. For example, when an inductive component is
measured with AC after the DC measurement, the extra delay time is
required to stabilize the measurement.

5.5 MULTI STEP MODE

This mode allows measurement of components at a number of user-defined steps. Limits and
parameters can be different for each defined step. MULTI STEP mode is divided into two
areas: MULTI STEP – Set and MULTI STEP – Run.

5.5.1 MULTI STEP – Set

Figure 5-1 MULTI STEP – Set Display

Up to 30 steps can be defined by highlighting the parameter, then entering the frequency with
the data entry keypad. The and navigation keys scroll through each entry in turn.

5.5.1.1 MULTI STEP – Set Parameters

Parameters which are common to MEASUREMENT MODE are described in section 4.4.2—
MEASUREMENT MODE Parameters.

5–4

PASS

Measurement result is within the limits set.

HI

The parameter indicated is above the upper limit.

LO

The parameter indicated is below the lower limit.

5.5.2 MULTI STEP – Run

Before a multi-step test can be run it must be set up as described in section 5.5.1. Pressing the
RUN soft key from MULTI STEP – Set mode enters MULTI STEP – Run mode.

When the Start soft key or the Trigger key is pressed, the meter will measure the component
step by step and the measurement values will be displayed. Also the meter will report PASS, HI
or LO according to the table below. Figure 5-2 shows the results of running the multi-step test
set up in section

Figure 5-2 MULTI STEP – Run

When the handler option is fitted, the handler Pass/Fail output corresponds to the ,

, results. The Pass/Fail output goes low only when a measurement has passed all set

limits.

5.5.2.1 MULTI STEP – Trigger Mode

Sng/Rep toggles between Auto Trigger Mode and Manual Trigger Mode. In manual mode,

the trigger key initiates measurement, in auto trigger mode, the measurement is initialled when
DUT has been connected to the test leads or fixture. The auto trigger has no effect to the
capacitive component because the scanning signal source is DC. The threshold for the auto
trigger function is 20kOhm and the trigger key remains effective even if the trigger is in the auto
mode.

5–5

Line frequency

Selection of Either 50Hz or 60Hz power line frequency.

Beep

Sets the buzzer state.

External trigger delay

Sets the external trigger delay time for external trigger control.

GPIB Address

The meter’s default GPIB address is 6. This may be changed by
highlighting the status page GPIB address parameter with the

and navigation keys, then altering the address with data

entry keypad. Allowable addresses are 0 to 30 inclusive.

5.6 The STATUS Page

The status page is displayed by pressing the STATUS soft key from the MAIN MENU.

Figure 5-3 The STATUS Page

There are four parameters which may be altered from within the status page: Line frequency,
Beep , External trigger delay and GPIB address.

5.6.1 The STATUS Page Parameters

6–1

SH1

Full source handshake

AH1

Full acceptor handshake

T6

Basic talker, serial poll, no talk only, untalk if MLA

TE0

No talker with secondary addressing

L4

Basic listener, no listen only, unlisten if MTA

LE0

No listener with secondary addressing

SR1

Full service request

DC1

Full device clear

RL1

Full remote/local compatibility

PP0

No parallel poll

DT1

Full device trigger compatibility

C0

No controller

6. GENERAL PURPOSE INTERFACE BUS (GPIB)

6.1 GPIB Control

6.1.1 Introduction

The GPIB is a parallel port designed to be used for communication between instruments
(listeners) and control devices (talkers) such as PCs fitted with a suitable interface card. The
interface protocol is defined by the IEEE488.1 standard. Some additional generic capabilities of
the listeners and talkers are defined by IEEE488.2. The SCPI standard defines the highest level
of command structure including a number of standard commands for all instruments.

6.1.2 Interface Specification

The IEEE 488.1 bus standard and the IEEE 488.2 code standard are fully supported. The
command set has also been designed to the SCPI standard.

The IEEE 488.1 functions supported

6.1.3 Changing GPIB Address

Each instrument on the GPIB requires a unique address, this can be set to any address in the
range 0 to 30.

The default address is 6. This may be changed from the STATUS page, as follows:

1) From the MAIN MENU select STATUS.

2) Highlight the status page GPIB address parameter with the and navigation keys.

3) Alter the address with the data entry keypad.

6–2

The GPIB address is stored in non-volatile memory.

6.1.4 Message Syntax

A GPIB message is made up of one or more commands. Commands can be separated into two
groups, common commands and subsystem commands. The available common commands are

defined by IEEE488.2 and are primarily concerned with the instrument’s GPIB configuration,

e.g. reading error registers and identifying the instrument. The subsystem commands are the
higher level commands that follow the SCPI guidelines and are concerned with setting up the
instrument functions, e.g. changing the frequency and drive level.

6.1.4.1 Message structure

Messages are sent to the instrument as ASCII character strings. The structure of these strings
can be seen in Figure 6-1. When interpreting the strings the instrument is not case-sensitive.

Figure 6-1 GPIB Message Structure

The path command prefix allows access to commands in the SCPI command tree. Using this
approach greatly simplifies GPIB programming by allowing related commands to be grouped
together. The next part of the string is the command itself which has the structure shown in
Figure 6-2. Multiple commands can be sent in one message by separating them with a
semicolon (maximum length 128 bytes). The terminator indicates the end of the command string
to the instrument: this can be the sending of the line-feed character (ASCII 0Ah) and/or the
assertion of the EOI handshake line on the GPIB bus.

Figure 6-2 GPIB Command Structure

Each instrument command begins with a mnemonic that describes the required action, e.g.
FREQ for changing the frequency.

If the command requires a parameter, then the next character should be a white space character
(ASCII 20h), although any character in the range 00h-20h can be used with the exception of
line-feed (ASCII 0Ah).

The parameter itself can take one of three forms depending on the command:

6–3

1) Discrete data

This includes words like ON, OFF and ABS.

2) Real Number

A floating point number that can be in engineering format or a number with a multiplier
suffix K (kilo-), M (mega-) or G (giga-).

For example:

FREQ 1000.0

FREQ 1E+3

FREQ 0.1E4

FREQ 1k

are all valid ways of setting a frequency of 1kHz.

3) Integer

A single integer number. Often used to indicate a Boolean state.
For example:

RANGE 1

will select range 1.
If invalid data is supplied then a command error will be generated. If data is supplied but

the instrument is not able to apply the setting, an execution error will be generated. If the
instrument is unable to exactly comply with the command and can only apply the nearest
available, a device specific error is generated. Details of these error codes can be found in
Figure 6-6.

6.1.4.2 Hierarchical Commands

As described in the previous section, SCPI uses a command tree to simplify device
programming. This structure is similar to the directory structure used on most computers. To

access a specific command in a specific mode the user must supply the ‘path’ to reach that

particular command within the tree.
When the unit is powered up the initial path is ‘root’ which is the top level from which all paths

must start.

Note that common commands (which by convention always start with the ‘*’ character) are not

part of the tree and can be accessed regardless of the current path.
So to select the impedance measurement function in measurement mode, the path must describe

the command tree as below:

6–4

The ‘:’ character is used as the path separator so the command string will be:

:MEAS:FUNC:Z

Note that the string starts with ‘:’. This tells the instrument to start from the ‘root’ path.

Whenever a terminator is reached (line-feed and/or EOI) the path is reset to the root path, so
each new GPIB command string must state the full path in order to work correctly, for example:

To set a measurement frequency of 1kHz at a level of 1.0V, the following string can be used:

:MEAS:FREQ 1k;LEV 1.0V <line-feed>

Or it can be expressed as two separate commands:

:MEAS:FREQ 1k <line-feed>

:MEAS:LEV 1.0 <line-feed>

However, the following will not work as the second command will be run from the ‘root’ path,

not the measurement path which was required:

:MEAS:FREQ 1k <line-feed>

LEV 1.0 <line-feed>

6–5

Summary: The following are the rules for negotiating the command hierarchy

 On power-up or reset, the current path is set to the root.
 Message terminator, line-feed (ASCII 0Ah) or EOI, sets the current path to the root.
 When a colon is the first character of a command, it specifies that the next command

mnemonic is a root level command.

 When a colon is placed between two path mnemonics, the current path is moved down one

level in the command tree if the path name is valid.

 A semicolon separates two commands in the same message without changing the current

path.

 If a command requires more than one parameter, the separate adjacent parameters must be

specified using a comma. Commas do not affect the current path.

 Common commands, such as *RST, *RCL, are not part of the tree. An instrument interprets

them in the same way, regardless of the current path setting.

Other syntax rules

 Commands will be executed in the order in which they appear in the string.
 A command string can contain any number of ‘query commands’: the response will contain

the replies to each query separated by a semicolon.

 Only commands available in the selected mode will be accepted. Otherwise, an Execution

Error will be generated. For example, AC frequency cannot be set if Rdc type of test is
selected

 Either full or abbreviated forms of the device specific commands will be accepted. The

abbreviated form is indicated by upper case letters in section 0.

 Device specific commands have the same effect as pressing the equivalent front panel key

and can be expected to interact with any other instrument settings in the same way.

6.1.5 Data Output

6.1.5.1 Output Syntax

For each query which generates an output response, a Response Message Unit (RMU), will be
generated. This consists of a string of numbers or alphanumeric characters; if more than one
RMU is generated they will be delimited with a semicolon. The terminator, line-feed and EOI
asserted indicates the end of data output. All characters will be upper case.

Figure 6-3 GPIB Data Output

6–6

BIT

Meaning True = ‘1’

7

Operation Status Event Register summary bit. This bit is true when
measurement or trimming etc., is in progress

6

RQS – ReQuest for Service. When the bit in the Service Request Enable
mask is set with the corresponding bit in the status register true, this will
trigger a service request to the controller.

MSS – Master Summary Status bit. The version of the request for service bit
which appears in the Status Byte.

5

ESB – Event Summary Bit. When unmasked by the ESE register, this bit will
be set whenever the corresponding bit or bits are set in the Event Status
Register.

4

MAV – Message available. The output queue has data to be read.

Figure 6-4 GPIB RMU Structure

6.1.5.2 Multiple Items

Some commands will generate an RMU containing more than one item of data (e.g. TRIG will
generate a first and second result). In this case, each item of response data will be separated by a
comma. Note that the maximum number of characters that can be output is 256, any data
beyond this will be lost.

If the command string contained multiple queries then the response will contain multiple RMUs,
each of which will be separated by a semicolon.

6.1.5.3 Numeric Format

The format of numeric results will correspond to that used for the instrument display, with the
engineering multiplier (if any) replaced by an equivalent 10’s exponent. If the FAST-GPIB
mode is being used then numbers will be output in a raw engineering format.

6.1.6 Status Reporting

6.1.6.1 Status byte

The status byte is used to summarize information from the other status groups. It is shown in
Figure 6-5, which conforms to IEEE 488.2 and SCPI. The status byte can be read by the query
command *STB? or by performing a serial poll on the instrument (these two are identical
although the point at which the RQS bit can be cleared is slightly different).

6–7

BIT

Meaning True = ‘1’

3

A summary bit from Questionable Data. This bit is not used, so is always 0.

2

This is a summary bit of error and instrument status messages. True if any
new status information is available.

1

Always 0.

0

Always 0.

Service

Request

Generation

Logical OR

Service Request
Enable Registert

*SRE <NR1> *SRE

read by *STB?

Status Bit Register

read by Serial Poll

{

{

ESB

MAV

QUES

Operation Status

Event Summary Bit

Instrument Error &

Status Summary Bit

Figure 6-5 Status Byte Register

6.1.6.2 Service Request Enable Register

The service request enable register (SRE) is a mask determining the conditions in which the
SBR will generate a service request. It is bit-wise ANDed with the SBR and if the result is not
zero then bit 6 of the SBR is set (see Figure 6-5). The SRE is set by the *SRE command and
read by the *SRE? command.

6–8

BIT

Name

Meaning (True = ‘1’)

7

Power On (PON)

True when the instrument power supply has been turned OFF and
then ON since the last time this register was read.

6

User Request (URQ)

Not used. Always 0.

5

Command Error (CME)

True if the following command errors occur:
An IEEE 488.2 syntax error occurred.
The device received a Group Execute Trigger (GET) inside a

program message.

4

Execution Error (EXE)

True when a parameter following a header of a GPIB command was
evaluated by the instrument as being outside of its legal input range
or is otherwise inconsistent with the instrument’s capabilities.

3

Device Dependent Error
(DDE)

True when any bit is set in the Encoded Message Register.

2

Query Error (QYE)

True when attempting to read data from the output buffer in which no
data was present, or when the data was lost.

1

Request Control (RQC)

Not used. Always 0.

0

Operation Complete (OPC)

True when the instrument has completed all selected pending
operations before sending the *OPC command

6.1.6.3 Standard Event Status Register

The standard event status register (ESR) contains the 8 bits of the operation status report which

is defined in IEEE 488.2. If one or more event status bit is set to ‘1’ and their enable bits are

also ‘1’, bit 5 (called ESB) of the status register byte is set to ‘1’.

Each bit of the standard event status register is shown below.

Figure 6-6 Standard Event Status Register

6–9

Summary Message

Event Summary Bit (ESB)

(Bit 5 of Status Byte Register)

Logical OR

Power On

User Request

Command Error

Standard Event

Enable Register

*ESE <NR1> *ESE?

Standard Event

Enable Register

*ESR?

Execution Error

Device Dependant Error

Query Error

Request Control

Operation Complete

Figure 6-7 Event Status Byte Register

6.1.6.4 Event Status Enable Register

The event status enable register (ESE) is a mask determining the conditions in which the ESR
will set bit 5 of the SBR. It is bit-wise ANDed with the ESR and if the result is not zero then
ESB (bit 5) of the SBR is set (see Figure 6-7). Thus any event affecting the ESR can be made to
generate a Service Request in conjunction with the ERE and the SRE.

The event status enable is set by the *ESE command and read by the *ESE? command.

6–10

0
1
2
3
4
5
6
7
8

9
10
11
12
13
14
15

Bit 7 of Status Byte

:STATus:OPERation:CONdition?

:STATus:OPERation:EVENt?

STATus:OPERation:ENABle <NR1>

Event register is updated on
transition of condition register.

Event register is masked by
the enable register then ORed
into a summary bit.

Calibrating
Settling
Ranging

Measuring

Always Zero

BIT

Meaning (True = ‘1’)

0

Calibrating bit which is true when S/C trimming, O/C trimming, or
calibrating is in progress, and otherwise reset.

4

Measuring bit which is true when measurement is in progress, and
otherwise reset.

Figure 6-8 Standard Operation Status Group

6.1.6.5 Standard Operation Status Group

The standard operation status group provides information about the state of the measurement
systems in the instrument. This status group is accessed through the STATus subsystem.
Standard operation status includes a condition register, event register, and an enable register.
Figure 6-8 illustrates the structure of standard operation status.

6.1.6.6 Standard Operation Status Condition Register

This is a 16-bit register gathering information about the state of the measurement systems in an
instrument. According to SCPI recommendation, we define:

Other bits are unused and are 0.

6.1.6.7 Standard Operation Status Event Register

This is a 16-bit register; each event bit in the event register corresponds to a condition bit in the
standard operation status condition register. According to SCPI recommendation, we define:

6–11

BIT

Meaning (True = ‘1’)

0

True when S/C trimming, O/C trimming, or calibration measurement is completed.

4

Set true when single shot measurement is completed.

Command

Name

Description

*CLS

Clear Status

Clears the Event Status Register and associated status
data structure.

*ESE <NR1>

Event Status Enable

Sets the Event Status Enable Register to the value of the
data following the command.

*ESE?

Event Status Enable Query

Returns the current contents of the Standard Event Status
Enable Register as an integer in the range 0 to 255.

*ESR?

Event Status Register Query

Returns the current contents of the Standard Event
Status Register as an integer in the range 0 to 255. It also
clears ESR.

*SRE <NR1>

Service Request Enable

Sets the Service Request Enable Register to the value
following the command. The register is set except that bit
6 is ignored.

*SRE?

Service Request Enable Query

Returns the current contents of the Service Request Enable
Register as an integer in the range 0 to 63 and 128 to 255.

*STB?

Status Byte Query

Returns the current contents of the Status Byte with the
Master Summary bits as an integer in the range 0 to 255.
Bit 6 represents Master Summary Status rather than
Request Service.

*IDN?

Identification Query

Returns the data identifying the instrument. (e.g. the data output
will be: ‘Microtest,6375 Series,0,1.0’ where the first field is the
manufacturer, then the model number, then a zero and the
software revision number: here represented as Issue 1.0).

*RST

Reset

Resets the instrument to a default setting. This command
is equivalent to a power-up reset.

*TRG

Trigger

Triggers a direct measurement, but does not return the
results to the controller. This is the same as a GET
(Group Execute Trigger) command.

*OPT

Option Identification Query

Returns the hardware options installed in the instrument.

Other bits are uncommitted and are always 0

6.1.7 Common Commands

Common commands are listed below. Their detailed description will be given later.

6–12

Command

Name

Description

*OPC

Operation Complete Command

Sets the OPC bit of the ESR register.

*OPC?

Operation Complete Query

Always returns 1 as instrument commands are always
processed sequentially.

*WAI

Wait-to-continue

Command has no effect as commands are processed
sequentially.

*LOC

Local

Set the instrument to local state.

Command

Description

Query

Read Status Operation

Condition register.

:STATus:OPERation:CON?

Read Status Operation

Event register

:STATus:OPERation:EVENt?

:STATus:OPERation:ENABle <NR1>

Set Status Operation

Enable Register

6.1.8 Standard Operation Status Commands

Refer to section 6.1.6 for an explanation of the following commands.

6–13

Command

Summary

Page

:MEAS

Select measurement mode/path.

6-17

:MEAS:TEST

Select test sub-path within measurement mode.

6-17

:MEAS:TEST:AC

Select AC measurement.

6-17

:MEAS:TEST:RDC

Select Rdc measurement.

6-17

:MEAS:TEST?

Measurement test query.

6-18

:MEAS:TRIGger

Trigger an AC or Rdc measurement.

6-18

:MEAS:FREQuency <real>

Set frequency of AC measurement.

6-18

:MEAS:FREQuency?

Frequency query.

6-18

:MEAS:LEVel <real>

Set drive level for currently selected test.

6-19

:MEAS:LEVel?

Drive level query.

6-19

:MEAS:SPEED <disc>

Select measurement speed.

6-19

:MEAS:SPEED?

Speed query.

6-19

:MEAS:RANGE <disc>

Select auto-ranging or range-hold on range N.

6-20

:MEAS:RANGE?

Range query.

6-20

:MEAS:EQU-CCT <disc>

Select equivalent circuit.

6-20

:MEAS:EQU-CCT?

Equivalent circuit query.

6-20

:MEAS:FUNC

Select function sub-path within measurement mode.

6-21

:MEAS:FUNC:C, L, X, B, Z, Y, Q, D, R or G

Select first or second AC measurement function.

6-21

:MEAS:FUNC:MAJOR?

First AC function query.

6-22

:MEAS:FUNC:MINOR?

Second AC function query.

6-22

:MEAS:SCALE <disc>

Show / Hide the scale bar.

6-23

:MEAS:SCALE?

Scale status query.

6-23

:MEAS:NOMinal <real>

Set nominal value for scale.

6-23

6.2 6375 Series Device-Specific Commands

The sub-system commands are grouped in different modes similar to the local operation. The
recommended discipline to control the instrument under GPIB is to select the mode and the
type of test first, then change the measurement conditions. Trying to change measurement
conditions which are not in the present mode and type of test will be rejected and return an
error flag.

6.2.1 Command Summary

6–14

Command

Summary

Page

:MEAS:NOMinal?

Nominal query.

6-23

:MEAS:LIMIT <disc>

Set percentage or absolute scale limits.

6-24

:MEAS:LIMIT?

Limit type query.

6-24

:MEAS:HIgh-LIMit <real>

Set scale high limit.

6-24

:MEAS:HIgh-LIMit?

High limit query.

6-24

:MEAS:LOw-LIMit <real>

Set scale low limit.

6-25

:MEAS:LOw-LIMit?

Low limit query.

6-25

:MULTI

Select multi-step mode / path.

6-26

:MULTI:SET

Switch to the multi-step set-up page.

6-26

:MULTI:RUN

Switch to the multi-step run page.

6-26

:MULTI:TEST

Select the step to edit.

6-27

:MULTI:TEST?

Return the number of the step that is currently being edited.

6-27

:MULTI:FUNC <disk>

Set measurement type for the currently selected step.

6-27

:MULTI:FUNC?

Returns the measurement type of the currently selected step.

6-27

:MULTI:FREQuency <real>

Set the frequency for the currently selected step.

6-28

:MULTI:FREQuency?

Returns the frequency of the currently selected step.

6-28

:MULTI:LEVel <real>

Set the drive level for the currently selected step.

6-28

:MULTI:LEVel?

Returns the drive level of the currently selected step.

6-28

:MULTI:SPEED <disk>

Set the measurement speed for the currently selected step.

6-29

:MULTI:SPEED?

Query the measurement speed of the currently selected step.

6-29

:MULTI:HIgh-LIMit <real>

Set the higher test limit of the currently selected step.

6-29

:MULTI:HIgh-LIMit?

Returns the high limit value of the currently selected step.

6-29

:MULTI:LOw-LIMit <real>

Set the lower test limit of the currently selected step.

6-30

:MULTI:LOw-LIMit?

Returns the low limit value of the currently selected step.

6-30

:MULTI:DELAY <real>

Set trigger delay time for currently selected step.

6-30

:MULTI:DELAY?

Returns the trigger delay time of the currently selected step.

6-30

:MULTI:DEL

Remove the current step.

6-30

:MULTI:TRIGger

Starts a run of multi-step measurements.

6-31

:MULTI:RES?

Query the results of the multi-step test.

6-31

6–15

Command

Summary

Page

:MULTI:NEW <filename>

Create a file under a new name.

6-31

:MULTI:SAVE

Save currently edited file.

6-32

MULTI:LOAD <filename>

Load an existed file to run or edit.

6-32

:CAL

Select calibrate mode / path.

6-43

:CAL:OC-TRIM <integer>

Perform open circuit trimming.

6-43

:CAL:SC-TRIM <integer>

Perform short circuit trimming.

6-44

:CAL:RES?

Returns the result of the calibration performed.

6-44

:TRIGger

Trigger a measurement in the current mode.

6-45

:TRIGger:DELay <real>

Set the external trigger delay time.

6-45

:TRIGger:DELay?

Trigger delay time query.

6-45

:LOC-TRIG <disc>

Select local trigger condition.

6-46

:LOC-TRIG?

Query the local trigger condition.

6-46

:REPeat <disc>

Enable repetitive measurements when unit is returned to local

6-46

:REPeat?

Query the trigger status.

6-46

:MODE?

Query the currently selected operating mode.

6-47

:DUMP-BMP

Returns the display as a windows compatible bitmap.

6-47

:BEEP

Set the buzzer condition.

6-48

:BEEP?

Buzzer condition query.

6-48

6–16

MEASUREMENT MODE

:MEAS

Select measurement mode.

Parameters:

None.

Response:

None.

:MEAS:TEST

Select test sub-path within measurement mode.

Parameters:

None.

Response:

None.

:MEAS:TEST:AC

Select AC measurement.

Parameters:

None.

Response:

None.

:MEAS:TEST:RDC

Select Rdc measurement.

Parameters:

None.

Response:

None.

6–17

MEASUREMENT MODE

:MEAS:TEST?

Measurement test query.

Parameters:

None.

Response:

0 AC measurement type.
1 Rdc measurement type.

:MEAS:TRIGger

Trigger a measurement using the current settings.

Parameters:

None.

Response:

For AC measurements the response will be the first and second measurements separated by
a comma.
Example: 68.860E-9 , 13.0E+6

For Rdc measurements the response will be a single measurement result.
Example: 6.2295E+3

:MEAS:FREQuency <real>

Set frequency of AC measurement.

Parameters:

The required frequency in Hertz. The
unit suffix ‘Hz’ is optional.

Example: MEAS:FREQ 1k
MEAS:FREQ 1000 Hz
MEAS:FREQ 1E3
are all equivalent commands and set

the test frequency to 1kHz.

Response:

None.

:MEAS:FREQuency?

Returns the current AC test frequency.

Parameters:

None.

Response:

Returns the current test frequency in
engineering format.

Example: +.10000000E+04
for a test frequency of 1kHz.

6–18

MEASUREMENT MODE

:MEAS:LEVel <real>

Set drive level for currently selected test.

Parameters:

The required level in Volt. The unit
suffix ‘V’ is optional.

Example: MEAS:LEV 1.2V
MEAS:LEV 200m
will select drive levels of 1.2V and
200mV respectively.

Response:

None.

:MEAS:LEVel?

Drive level query.

Parameters:

None.

Response:

Returns the current test level in
engineering format.

Example: +.20000000E-01
for a test level of 20mV.

:MEAS:SPEED <disc>

Select the required measurement speed.

Parameters:

MAX Maximum speed.
FAST Fast speed.
MED Medium speed.
SLOW Slow speed.

Example: :MEAS:SPEED SLOW
will select slow speed for

measurements.

Response:

None.

:MEAS:SPEED?

Returns the current test speed.

Parameters:

None.

Response:

Returns the test speed as an integer
according to the table:

0 Maximum
1 Fast
2 Medium
3 Slow

Example: 1
indicates that Fast measurements are

selected.

6–19

MEASUREMENT MODE

:MEAS:RANGE <disc>

Select the required measurement range
condition for AC and RDC tests.

Parameters:

The following parameters are valid:

AUTO Auto-ranging.
HOLD Hold current range.
1 to 7 Range 1 to 7
Example: MEAS:RANGE 1

MEAS:RANGE AUTO

will select range 1 and auto-ranging
respectively.

Response:

None.

:MEAS:RANGE?

Returns the current measurement range.

Parameters:

None.

Response:

Returns the measurement range as an
integer according to this table:

0 Auto-ranging.
1-7 Current measurement range.

Example: 0
indicates that auto ranging is selected.

:MEAS:EQU-CCT <disc>

Select the equivalent circuit type for AC
tests.

Parameters:

The following parameters are valid:

SER Series equivalent circuit.
PAR Parallel equivalent circuit.

Example: :MEAS:EQU-CCT SER
will select the series equivalent circuit.

Response:

None.

:MEAS:EQU-CCT?

Returns the currently selected equivalent
circuit.

Parameters:

None.

Response:

Returns the equivalent circuit flag
according to this table:

0 Parallel.
1 Series.

Example: 0
indicates the parallel equivalent circuit

is selected.

6–20

MEASUREMENT MODE

:MEAS:FUNC

Select function sub-path within measurement mode.

Parameters:

None.

Response:

None.

:MEAS:FUNC:C, L, X, B, Z, Y, Q, D, R, G

Select first or second AC measurement function.
Selecting first measurement:

:MEAS:FUNC:C Capacitance.
:MEAS:FUNC:L Inductance.
:MEAS:FUNC:X Reactance.
:MEAS:FUNC:B Susceptance.
:MEAS:FUNC:Z Impedance.
:MEAS:FUNC:Y Admittance.

Selecting second measurement:

:MEAS:FUNC:Q Quality factor.
:MEAS:FUNC:D Dissipation factor.
:MEAS:FUNC:R Resistance.
:MEAS:FUNC:G Conductance.

Note that selecting Z or Y as the first measurement will force the second measurement to be
Angle. This does not change the equivalent circuit flag setting.

Example: :MEAS:FUNC:C;D
will select C+D measurements.

6–21

MEASUREMENT MODE

:MEAS:FUNC:MAJOR?

First AC function query.

Parameters:

None.

Response:

Returns the measurement type according to this table:

0 Capacitance
1 Inductance.
2 Reactance.
3 Susceptance.
4 Impedance.
5 Admittance.

Example: 4
indicates that the first measurement is impedance (Z).

:MEAS:FUNC:MINOR?

Second AC function query.

Parameters:

None.

Response:

Returns the measurement type according to this table:

0 Q-Factor.
1 D-Factor.
2 Resistance.
3 Conductance.

Example: 1
indicates that the second measurement is dissipation factor (D). Note that if the first

measurement is polar (Z or Y), this query will return the last non-polar setting.

6–22

MEASUREMENT MODE

:MEAS:SCALE <disc>

Show / Hide the scale bar.

Parameters:

The following parameters are valid:

ON Show scale.
OFF Hide scale.

Example: :MEAS:SCALE OFF
will turn off the scale.

Response:

None.

:MEAS:SCALE?

Returns the current status of the scale bar.

Parameters:

None.

Response:

Returns scale setting according to this
table:

0 Scale hidden.
1 Scale visible.

Example: 0
indicates that the scale is currently

hidden.

:MEAS:NOMinal <real>

Set nominal value for scale.

Parameters:

The required nominal value. If a unit is
supplied it must that of either the first
or second measurement otherwise the
unit mismatch error will be set. If no
unit is supplied the current nominal
unit will be used.

Examples:

:MEAS:NOMINAL 1e-6F

will set a nominal of 1µF.

:MEAS:NOMINAL 0.47e-5

will set a nominal of 4.7µF

Response:

None.

:MEAS:NOMinal?

Returns the scale bar graph nominal value.

Parameters:

None.

Response:

Returns the nominal in engineering
format.

Example: +.10000000E-01
would indicate a nominal of 10mH if

the first nominal unit is Henrys.

6–23

MEASUREMENT MODE

:MEAS:LIMIT <disc>

Set percentage or absolute scale limits.

Parameters:

The following discrete parameters are
valid:

ABS Absolute limits.
PERC Percentage limits.

Example: :MEAS:LIMIT PERC
will select percentage limits.

Response:

None.

:MEAS:LIMIT?

Limit type query.

Parameters:

None.

Response:

Returns the scale bar limits according
to this table:

0 Absolute scale.
1 Percentage scale.

Example: 0
indicates that the scale bar currently

has absolute limits.

:MEAS:HIgh-LIMit <real>

Set scale high limit.

Parameters:

The required high limit. No unit should
be supplied: the nominal unit is used.

Example: :MEAS:HI-LIM 5.0
will set a high limit of +5.0% of

nominal.

Response:

None.

:MEAS:HIgh-LIMit?

Returns the current scale bar percentage
high limit.

Parameters:

None.

Response:

The current high limit in engineering
format.

Example: +.25000000E+01
indicating a high limit of +2.5% of

nominal.

6–24

MEASUREMENT MODE

:MEAS:LOw-LIMit <real>

Set scale low limit.

Parameters:

The required low limit. No unit should
be supplied: the nominal unit is used.

Example: :MEAS:LO-LIM -5.0
will set a low limit of -5.0% of

nominal.

Response:

None.

:MEAS:LOw-LIMit?

Returns the current scale bar percentage
low limit.

Parameters:

None.

Response:

The current low limit in engineering
format.

Example: -.20000000E+01
indicating a high limit of -2.0% of

nominal.

6–25

MULTI-STEP MODE

:MULTI

Select multi-step mode / path.

Parameters:

None.

Response:

None.

:MULTI:SET

Switch to the multi-step set-up page.

Parameters:

None.

Response:

None.

:MULTI:RUN

Switch to the multi-step run page.

Parameters:

None.

Response:

None.

6–26

MULTI-STEP MODE

:MULTI:TEST

Select the step to edit.

Parameters:

The step number in the range 1 to 30.
Example: :MULTI:TEST 1
will select the top frequency for editing

Response:

None.

:MULTI:TEST?

Return the number of the step that is
currently being edited.

Parameters:

None.

Response:

The frequency number in the range 1 to

30.
Example: 30
would indicate the last frequency is

selected for editing.

:MULTI:FUNC

Set measurement function for currently
selected step.

Parameters:

The following discrete parameters are
valid:

LS, LP, Q, CS, CP, D, Z, PHASE,

RS, RP, X, G, B, Y, RDC.

Response:

None.

:MULTI:FUNC?

Parameters:

None.

Response:

Returns the measurement type according to
This table:
1 Z 9 P
2 Ls 10 Q
3 Lp 11 D
4 Cs 12 Rs
5 Cp 13 Rp
7 Y 14 B
8 G 15 X
16 RDC

6–27

MULTI-STEP MODE

:MULTI:FREQuency <real>

Set frequency for currently selected step.

Parameters:

The required frequency in Hertz. The
unit suffix ‘Hz’ is optional.

Example: MULTI:FREQ 1k
MULTI:FREQ 1000 Hz
MULTI:FREQ 1E3
are all equivalent commands and set

the test frequency to 1kHz for currently
selected step.

Response:

None.

:MULTI:FREQuency?

Frequency query of currently selected step.

Parameters:

None.

Response:

Returns the current test frequency in
engineering format.

Example: +.10000000E+04
for a test frequency of 1kHz.

:MULTI:LEVel <real>

Set drive level for currently selected step.

Parameters:

The required level in Volt. The unit
suffix ‘V’ is optional.

Example: MULTI:LEV 1.2V
MULTI:LEV 200m
will select drive levels of 1.2V and
200mV respectively.

Response:

None.

:MULTI:LEVel?

Drive level query of currently selected step.

Parameters:

None.

Response:

Returns the current test level in
engineering format.

Example: +.20000000E-01
for a test level of 20mV.

6–28

MULTI-STEP MODE

:MULTI:SPEED <disc>

Select the required measurement speed for
currently selected step.

Parameters:

MAX Maximum speed.
FAST Fast speed.
MED Medium speed.
SLOW Slow speed.

Example: :MULTI:SPEED SLOW
will select slow speed for currently

selected step.

Response:

None.

:MULTI:SPEED?

Returns the test speed of currently selected
step.

Parameters:

None.

Response:

Returns the test speed as an integer
according to the table:

0 Maximum
1 Fast
2 Medium
3 Slow

Example: 1
indicates that Fast measurements are

selected.

:MULTI:HIgh-LIMit <real>

Set the higher test limit of the currently
selected step.

Parameters:

The required higher limit.
example: :MULTI:HI-LIM

10.0
will set a high limit to 10.

Response:

None.

:MULTI:HIgh-LIMit?

Returns the high limit value of the
currently selected step.

Parameters:

None.

Response:

The high limit value in engineering
format.

Example: +.50000000E+01
indicates a high limit to5.

6–29

MULTI-STEP MODE

: MULTI:LOw-LIMit <real>

Set the lower test limit of the currently
selected step.

Parameters:

The required lower limit.
Example: :MULTI:LO-LIM

10.0
will set a low limit to 10.

Response:

None.

: MULTI:LOw-LIMit?

Returns the low limit value of the currently
selected step.

Parameters:

None.

Response:

The low limit value in engineering
format.

Example: -.50000000E+01
indicates a high limit to 5.

:MULTI:DELAY <real>

Set the delay time of the currently selected
step.

Parameters:

The required delay time in Second.
Example: :MULTI:DELAY 0.1
:MULTI:DELAY 100m
will set delay time to 0.1 Second.

Response:

None.

:MULTI:DELAY?

Returns the delay time of the currently
selected step.

Parameters:

None.

Response:

Example: : 0.1
Indicates the delay time is 0.1 Second.

:MULTI:DEL

Remove the current step.

Parameters:

The step number in the range 1 to 30
Example: MULTI:DEL 1
will delete the top step.

Response:

None.

6–30

MULTI-STEP MODE

:MULTI:TRIGger

Starts a run of multi-step measurements.

Parameters:

None.

Response:

None.

:MULTI:RES?

Query the results of the multi-step test.

Parameters:

None

Response:

Each result is separated by a comma and the PASS/FAIL flag will prefix the result.

0 PASS,
1 FAIL (HI)
2 FAIL (LO)

Examples: 1, +.68898363E-07, 0, +.72168059E-04
would indicate a fail result for step 1 and a pass result for step 2.

MULTI:NEW <filename>

Create a file under a new name to store the multi-step data.

Parameters:

A File name, 8 characters at most.
Example: :MULTI:NEW DEMO
will create a new file with the name DEMO.

Response:

None.

6–31

MULTI-STEP MODE

MULTI:SAVE

Store current multi-step data to currently selected file.

Parameters:

None.

Response:

None.

MULTI:LOAD <filename>

Load an existed file to run or edited.

Parameters:

A File name, 8 characters at most.
Example: :MULTI:LOAD DEMO
will load a file which name is DEMO.

Response:

None.

6–32

CALIBRATE MODE

:CAL

Select calibrate mode / path.

Parameters:

None.

Response:

None.

:CAL:OC-TRIM <integer>

Perform open circuit trimming.

Parameters:

The required trim type.

1 Spot trim.
2 Up to 10kHz.
3 Up to 100kHz.
4 All frequency.

Example: :CAL:OC-TRIM 4
would perform an open circuit trim across the whole frequency range of the unit.

Response:

None.

6–33

CALIBRATE MODE

:CAL:SC-TRIM <integer>

Perform short circuit trimming.

Parameters:

The required trim type.

1 Spot trim.
2 Up to 10kHz.
3 Up to 100kHz.
4 All frequency.

5 RDC
Example: :CAL:SC-TRIM 1
would perform a short circuit trim at the current frequency.

Response:

None.

:CAL:RES?

Returns the result of the most recent trim or calibration performed.

Parameters:

None.

Response:

The trim flag:

1 Calibration passed.
0 Calibration failed.

Example: 1
would indicate that the last trim or calibration was successful.

6–34

ROOT COMMANDS

:TRIGger

Trigger a measurement in the current mode.

Parameters:

None.

Response:

The measurement result depending on the mode.

:TRIGger:DELAY <real>

Set the trigger delay time for the external
trigger.

Parameters:

The required delay time in Second. The
unit suffix. ‘S’ is optional.

Example: TRIG:DELAY 0.2
TRIG:DELAY 200m
are all equivalent commands and set

the trigger delay time to 200mS.

Response:

None.

:TRIGger:DELAY?

Query the external trigger delay time.

Parameters:
None.

Response:

Returns the external trigger delay
time.

Example: 0.2

Indicates the external trigger delay time is
200mS.

6–35

ROOT COMMANDS

:LOC-TRIG <disc>

Select local trigger condition. When local
trigger is ON the trigger button on the front
panel can be used to take a measurement,
all other functions being under remote
control.

Parameters:

ON Enable local trigger.
OFF Disable local trigger.

Example: :LOC-TRIG ON
will allow triggering from the front

panel.

Response:

None.

:LOC-TRIG?

Query the local trigger condition.

Parameters:

None.

Response:

The local trigger flag:

1 Local trigger enabled.
0 Local trigger disabled.

:REPeat <disc>

Enable repetitive measurements when unit
is returned to local control.

Parameters:

The required state:

ON Repetitive
OFF Single shot

Example: :REP ON
will set the unit to repetitive mode

when it is returned to local control.

Response:

None.

:REPeat?

Query the trigger status.

Parameters:

None.

Response:

The selected trigger mode.

0 Single shot
1 Repetitive

Example: 1
would indicate that the instrument

will begin repetitive measurements
when returned to local control.

6–36

ROOT COMMANDS

:MODE?

Query the currently selected operating mode.

Parameters:

None.

Response:

The current mode:

0 Main menu.
1 Measurement.
4 Multi-step.
7 Calibrate.
8 Status.

Example: 1
would indicate that Measurement Mode is selected.

:DUMP-BMP

Returns the display as a windows compatible bitmap. The data conforms to IEEE 488.2 or
SCPI ‘Indefinite Length Arbitrary Block Response Data’.

Parameters:

None.

Response:

None.

6–37

ROOT COMMANDS

:BEEP <disc>

Set the buzzer function.

Parameters:

The required state:

OFF Buzzer is disabled.
PASS Turns on the buzzer if test result

is pass.

FAIL Turns on the buzzer if test result

is fail.

Response:

None.

:BEEP?

Query the buzzer condition.

Parameters:

None.

Response:

The buzzer condition.

0 OFF
1 PASS

2 FAIL
Example: 1
would indicate that the buzzer will be

turned on if test result is pass.

6.3 Example Programs

The following examples are written for Microsoft QuickBasic 4.5 running on a PC with a
National Instruments GPIB controller. The programs are short and can be readily converted to
another language/platform as their function is primarily to illustrate the use of the instrument
GPIB commands.

Example 1:

Simple identification query, use this program to establish that the GPIB configuration is
correct.

Example 2:

Simple measurement program. This program triggers a single AC measurement and displays
the result.

Example 3:

Simple querying example. This program interrogates the instrument and display the current
values for a number of AC measurement settings.

Example 4:

Multi-step example for AC tests. This program sets up a 4-measurements multi-step test and
displays the results from a single trigger.

6–38

6.3.1 Example 1

' **************************************************************
'
' Program 1 : Simple GPIB operation check Version 1.0
'
' Platform : QuickBasic 4.5
'
' Description :
'
' This program will ask the instrument to identify itself.
' It assumes the instrument is called 'WK' in the National
' Instruments configuration.
'
' **************************************************************

' $INCLUDE: 'QBDECL.BAS' ' National Instruments include file.

buf$ = SPACE$(200) ' Buffer for GPIB response.

CLS ' Clear the screen

CALL IBFIND("WK", wk%) ' Look for 'WK'

IF wk% < 0 THEN ' Check that the id was found.
PRINT "Identifier 'WK' not found"
PRINT "Please check your configuration."
END
END IF

CALL IBCLR(wk%) ' Clear the device.
IF IBSTA% < 0 THEN ' Check for a problem.
PRINT "Error clearing instrument"
PRINT "Please check you configuration."
END
END IF

CALL IBWRT(wk%, "*IDN?") ' Request identification.
IF IBSTA% < 0 THEN ' Check for a problem.
PRINT "Error writing to instrument"
PRINT "Please check that the instrument"
PRINT "is powered, set to the correct"
PRINT "GPIB address and the cable is"
PRINT "securely connected."
END
END IF

CALL IBRD(wk%, BUF$) ' Read the response.
IF IBSTA% < 0 THEN ' Check for a problem.
PRINT "Error reading from instrument"
PRINT "Please check the device configuration"
END
END IF

PRINT buf$ ' Display the response.

END ' The end.

6–39

6.3.2 Example 2

' **************************************************************
'
' Program 2 : Simple Measurement Version 1.0
'
' Platform : QuickBasic 4.5
'
' Description :
'
' This program will set-up and run a single Z+Angle measurement
' on a component.
' This program assumes that the GPIB configuration is correct
' enough to be able to run example program 1 correctly.
'
' **************************************************************
' $INCLUDE: 'QBDECL.BAS' ' National Instruments include file.
CLS ' Clear the screen.

' Initialise the GPIB
CALL IBFIND("WK", wk%) ' Look for 'WK'.
CALL IBCLR(wk%) ' Clear the device.

' Select the required operating mode
CALL IBWRT(wk%, ":MEAS") ' Go to measurement mode.
CALL IBWRT(wk%, ":MEAS:TEST:AC")
CALL IBWRT(wk%, ":MEAS:FUNC:Z") ' Select Z+Angle.

' Set-up measurement conditions.
' Level = 100mV Freq = 10kHz
' Speed = Medium
' Range = AUTO
CALL IBWRT(wk%, ":MEAS:LEVEL 0.1; FREQ 1E4; SPEED MED")
CALL IBWRT(wk%, ":MEAS:RANGE AUTO")

' Perform the measurement.
buf$ = SPACE$(200) ' Prepare buffer for GPIB response.
CALL IBWRT(wk%, "TRIG") ' Trigger a measurement.
CALL IBRD(wk%, buf$) ' Read in the response.
buf$ = LEFT$(buf$, ibcnt% - 1) ' Remove trailing characters.

' The next piece of code extracts the numbers from
' the response so that they can be manipulated.
first = VAL(LEFT$(buf$, INSTR(buf$, ",") - 1))
second = VAL(RIGHT$(buf$, LEN(buf$) - INSTR(buf$, ",") - 1))

' Display the final result.
PRINT " Z = "; first
PRINT "Angle = "; second

END ' The end.

6.3.3 Example 3

DECLARE FUNCTION GPIBQuery$ (id%, Query$)
' **************************************************************
'

6–40

' Program 3 : Querying the instrument state Version 1.0
'
' Platform : QuickBasic 4.5
'
' Description :
'
' This program will use queries to find out the current settings
' of the unit.
' This program assumes that the GPIB configuration is correct
' enough to be able to run example program 1 correctly.
'
' **************************************************************
' $INCLUDE: 'QBDECL.BAS' ' National Instruments include file.
CLS ' Clear the screen.

' Initialise the GPIB
CALL IBFIND("WK", wk%) ' Look for 'WK'.
CALL IBCLR(wk%) ' Clear the device.

' Select the required operating mode
CALL IBWRT(wk%, ":MEAS") ' Go to measurement mode.
CALL IBWRT(wk%, ":MEAS:TEST:AC") ' Select AC measurements.

' Start querying
freq = VAL(GPIBQuery$(wk%, ":MEAS:FREQ?")) ' Query the AC frequency.
level = VAL(GPIBQuery$(wk%, ":MEAS:LEV?")) ' Query the AC level.
range = VAL(GPIBQuery$(wk%, ":MEAS:RANGE?")) ' Query the range.
speed = VAL(GPIBQuery$(wk%, ":MEAS:SPEED?")) ' Query the speed.

' Print the status of the major settings.
PRINT "AC Frequency ="; freq; "Hz" ' Print the AC frequency.

PRINT "AC Drive level ="; level; "V" ' Print the AC level.

PRINT "AC Range ="; ' Print the AC range.
IF range = 0 THEN
PRINT " AUTO"
ELSE
PRINT range
END IF

PRINT "SPEED = "; ' Print the test speed.
SELECT CASE speed
CASE 3
PRINT "SLOW"
CASE 2
PRINT "MEDIUM"
CASE 1
PRINT "FAST"
CASE 0
PRINT "MAX"
END SELECT

END ' The end.

' This function sends the supplied query to the instrument
' and reads back the reply and strips the trailing characters
FUNCTION GPIBQuery$ (id%, Query$)
buf$ = SPACE$(80) ' Initialise the buffer.

6–41

CALL IBWRT(id%, Query$) ' Query the level
CALL IBRD(id%, buf$) ' Read in the response.
GPIBQuery$ = LEFT$(buf$, ibcnt% - 1) ' Remove trailing characters.
END FUNCTION

6.3.4 Example 4

DECLARE FUNCTION GPIBQuery$ (id%, Query$)
' **************************************************************
'
' Program 4 : Multi-step mode Version 1.0
'
' Platform : QuickBasic 4.5
'
' Description :
'
' This program sets up and runs a simple 4 frequency measurement
' in Multi-step mode
'
' **************************************************************
' $INCLUDE: 'QBDECL.BAS' ' National Instruments include file.
CLS ' Clear the screen.

' Initialise the GPIB
CALL IBFIND("WK", wk%) ' Look for 'WK'.
CALL IBCLR(wk%) ' Clear the device.

' Go to multi-step mode
CALL IBWRT(wk%, ":MULTI") ' Multi-frequency mode
CALL IBWRT(wk%, ":MULTI:SET") ' Multi-frequency set-up

' Set-up steps
CALL IBWRT(wk%, ":MULTI:TEST 1; FUNC LS; FREQ 1k, LEV 1") ' Step 1
CALL IBWRT(wk%, ":MULTI:TEST 2; FUNC RS; FREQ 1k, LEV 1") ' Step 2
CALL IBWRT(wk%, ":MULTI:TEST 3; FUNC Q; FREQ 1k, LEV 1") ' Step 3
CALL IBWRT(wk%, ":MULTI:TEST 4; FUNC DCR") ' Step 4
CALL IBWRT(wk%, ":MULTI:TRIG")

PRINT GPIBQuery(wk%, ":MULTI:RES?") ' Get result

END ' The end!

' This function sends the supplied query to the instrument
' and reads back the reply and strips the trailing characters
FUNCTION GPIBQuery$ (id%, Query$)
buf$ = SPACE$(80) ' Initialise the buffer.
CALL IBWRT(id%, Query$) ' Query the level
CALL IBRD(id%, buf$) ' Read in the response.
GPIBQuery$ = LEFT$(buf$, ibcnt% - 1) ' Remove trailing characters.
END FUNCTION

7–1

7. 6375 SERIES SPECIFICATION

Microtest reserves the right to change specification without notice

7.1 Measurement Parameters

Any of the following parameters can be measured and displayed:

DC Function

Resistance (Rdc).

AC Functions

Capacitance (C), Inductance (L), Resistance (R), Conductance (G), Susceptance (B),
Reactance (X), Dissipation Factor (D), Quality Factor (Q), Impedance (Z), Admittance (Y) and
Phase Angle ().

The following display formats are available:

Series or Parallel Equivalent Circuit

C+R, C+D, C+Q, L+R, L+Q

Series Equivalent Circuit Only

X+R, X+D, X+Q

Parallel Equivalent Circuit Only

C+G, B+G, B+D, B+Q

Polar Form

Z + Phase Angle, Y + Phase Angle

7.2 Test Conditions

7.2.1 AC Drive

7.2.1.1 Frequency Range

20Hz to 200KHz (6375)
20Hz to 500KHz (6376)
20Hz to 1MHz (6377)
20Hz to 5MHz (6378)
20Hz to 10MHz (6379)
Resolution: 5 digits
Accuracy of set frequency ±0.005%,

7–2

Test Frequency

DC

≦100Hz

≦2kHz

>2kHz

≧1MHz

MAX

30ms

600ms

120ms

75ms

120 ms

FAST

60ms

650ms

180ms

140 ms

150 ms

MEDIUM

120ms

1.2S

470ms

450 ms

470 ms

SLOW

900ms

1.3S

600ms

600 ms

620 ms

7.2.1.2 Drive Level (AC & DC Measurements)

Open circuit voltage:10mV to 2V
Short circuit current:100MA to 20mA
Signal source impedance:100Ω nominal

Resolution:10mV
Accuracy:2%±5mV

7.3 Measurement Speeds

Four selectable speeds for all measurement functions. Selecting slower measurement speed
increases reading resolution and reduces measurement noise by averaging.

7–3

R, Z , X

0.01mΩ to 1GΩ

G, Y, B

0.001nS to 1kS

L

0.1nH to 100kH

C

0.001pF to 1F

D

0.00001 to 1000

Q

0.01 to 1000

Rdc

0.01mΩ to 100MΩ

7.4 Display Range

7.5 Modes Of Operation

7.5.1 MEASUREMENT

Selection of any measurement parameter and test condition.
Single-level function-menu controlled by keypad and soft keys.
Single and repetitive measurements displaying major and minor terms.
Analogue scale with configurable Hi/Lo limits giving PASS/FAIL indication.

7.5.2 MULTI-STEP

Measurement parameters and test conditions set using MULTI-STEP SET MODE.
Up to 30 steps with configurable limits.
PASS/FAIL indication.
Up to 64 multi-step programs can be saved in the non-volatile memory.

7.6 Measurement Connections

4 front panel BNC connectors with the screens at ground potential.
Terminals withstand connection of charged capacitor up to 5V, either polarity.

7.7 Measurement Accuracy

The accuracy statements given apply when the instrument is used under the following
measurement conditions.

7–4

Slow speed, 4-terminal measurement. The instrument must have warmed up for at least 30
minutes at a steady ambient temperature of between 18C and 28C. The instrument must have
been trimmed with its measuring leads and fixture at the measurement frequency.

Except on the highest and lowest hardware measurement ranges, the accuracy chart also apply
to medium speed. For maximum and fast speed, the figure must be doubled.

Measurement accuracy for the multi-step mode conforms to the maximum speed setting.

7–5

7.8 Accuracy Chart

Accuracy chart define the measurement ranges available, at specified accuracies, over the
available frequency band. All curves assume that Slow measurement speed is used, that the
meter has been trimmed at the frequency and level used for measurements, factory calibration
are valid and that the component under test is pure.

7.8.1 |Z| Accuracy Chart

7–6

7.8.2 |Z| vs L, C Chart

7–7

7.8.3 |Z|, |Y|, L, C, R, X, G, B and Rdc Accuracy

For high impedance (>10kOhm) value:

Ae[%] = ((A + 0.0000001*Zx) * Kv * Kt)

For low impedance (<100Ohm) value

Ae[%] = ((A + 0.1/Zx) * Kv * Kt)

Where,
A= Accuracy from accuracy chart
Zx= Measured value of unknown component
Kv= Test voltage factor (Refer to Table A)
Kt= Temperature factor (Refer to Table B)

L, C, X, and B accuracy apply when D < 0.1
R, G accuracy apply when Qx < 0.1

When D ≧ 0.1, multiply Ae by √ 1 + D² for L, C, X and B accuracies.
When Q≧ 0.1, multiply Ae by √1 + Q² for R, and B accuracies

Rdc Accuracy= Refer to Z accuracy at 20Hz

7.8.4 D Accuracy

De = (Ae / 100)
If D > 0.1, multiply D accuracy by (1+D²)

7.8.5 Q Accuracy

Qe = ((Qx²*De) / (1Qx*De))

Where, Qx is the measured Q value,
De is the relative D accuracy.

Accuracy applies when Qx * De < 1

7–8

Level

Kv

≧ 1.250

1.2

≧ 0.625

1

≧ 0.313

1.2

≧ 0.156

1.5

≧ 0.078

2

≧ 0.039

2.5

≧ 0.02

5

≧ 0.010

10

Temperature(°C)

Kt

8-18

2

18-28

1

28-35

2

Table A. Test voltage factor

Table B Temperature factor

7–9

Input Voltage

115V AC ±10% or 230V AC ±10% (selectable)

Frequency

50/60Hz

VA rating

150VA max

Input fuse rating

115/230V operation: 3AT

The input fuse is in the fuse holder drawer integral to the IEC input connector.

Height

150mm

Width

340mm

Depth

460mm

Weight

6.5kg

7.9 General

7.9.1 Power Supply

7.9.2 Display

High contrast black and white LCD module 320 x 240 pixels with CPL back lighting.
Visible area 115 x 86mm.

7.9.3 Remote Control

Designed to GPIB IEEE-488.2 and SCPI 1992.0.

7.9.4 Remote Trigger

Rear panel phone jack with internal pull-up, operates on logic low or contact closure.

7.9.5 Mechanical

7.10 Environmental Conditions

This equipment is intended for indoor use only in a non-explosive and non-corrosive
atmosphere.

7.10.1 Temperature Range

Storage: -40°C to +70°C.
Operating: 0°C to 40°C.
Normal accuracy: 23±5°C.

7.10.2 Relative Humidity

Up to 80% non-condensing.

7–10

7.10.3 Altitude

Up to 2000m.

7.10.4 Installation Category

II in accordance with IEC664.

7.10.5 Pollution Degree

2 (mainly non-conductive).

7.10.6 Safety

Complies with the requirements of EN61010-1.

7.10.7 EMC

Complies with EN61326 for emissions and immunity.

8–1

B Susceptance (= 1/X)

R Resistance

C Capacitance

X Reactance

D Dissipation factor (tan δ)

Y Admittance (= 1/Z)

E Voltage

Z Impedance

G Conductance (= 1/R)

ω 2π x frequency

I Current

L Inductance

Subscript s (s) = series

Q Quality (magnification) factor

Subscript p (p) = parallel

complex) terms(all

I

E

Z 

Z

1

E

I

Y 

C

j

- R Lj R jX R Z

s





 

22

s

X R Z 

 

22

p

X R

RX

Z

L

j

-G Cj G jB G Y

p





 

22

p

B G Y 

 

22

s

B G

GB

Y

L

1

B C B

C

1

X L X where LCCL









values)C L, R, (series

RC

1

R

L

Q

SSS

S









valuesC L, R, (parallel RC

L

R

Q

PP

P

P







8. THEORY REFERENCE

8.1 Abbreviations

8.2 Formulae

8–2

values)C L, G, (parallel GL

C

G

D

PP

P

P







values)C L, R, (series RC

L

R

D

SS

S

S







convention allelseries/par of regardlessconstant is

D

1

Q valueThe :Note 

 

2

P

S

Q 1

R

R

 

2

SP

Q 1R R 

 

2

PS

D 1 C C 

 

2

S

P

D 1

C

C



















2

P

S

Q

1

1

L

L

















2

SP

Q

1

1L L

 cos Z R

S

 cos Y G

P

 sin Z X

S

 sin Y B

P





tan

1

Q

8.3 Series/Parallel Conversions

Conversions using the above formulae will be valid only at the test frequency.

8.4 Polar Derivations

Note that, by convention, +ve angle indicates an inductive impedance or capacitive admittance.
If capacitance is measured as inductance, the L value will be –ve.
If inductance is measured as capacitance, the C value will be –ve.
D = tan δ where δ = (90 – θ)˚ admittance measurement.

where δ = (90 – θ)˚ impedance measurement.

9–1

9. MAINTENANCE, SUPPORT AND SERVICES

9.1 Guarantee

The equipment supplied by is guaranteed against defective material and faulty manufacture for
a period of twelve months from the date of dispatch. In the case of materials or components
employed in the equipment but not manufactured by us, we allow the customer the period of
any guarantee extended to us.

The equipment has been carefully inspected and submitted to comprehensive tests at the factory
prior to dispatch. If, within the guarantee period, any defect is discovered in the equipment in
respect of material or workmanship and reasonably within our control, we undertake to make
good the defect at our own expense subject to our standard conditions of sale. In exceptional
circumstances and at the discretion of the service manager, a charge for labour and carriage
costs incurred may be made.

Our responsibility is in all cases limited to the cost of making good the defect in the equipment
itself. The guarantee does not extend to third parties, nor does it apply to defects caused by
abnormal conditions of working, accident, misuse, neglect or wear and tear.

9.2 Maintenance

9.2.1 Cleaning

The body of the equipment can be cleaned with a damp lint-free cloth. Should it be required,
weak detergents can be used. No water must enter the equipment. Do not attempt to wash down
internal parts.

9.2.2 Safety Checks

Each year the equipment should be given a simple safety check.

9.2.2.1 Equipment required

25A ground bond tester (e.g. Megger PAT 2)
Insulation tester @ 500V DC (e.g. Megger BM 7)

9.2.2.2 Tests

1) DISCONNECT THE INSTRUMENT FROM THE AC POWER SUPPLY!

2) Inspect the unit and associated wiring for damage e.g. dents or missing parts which might

impair the safety or function of the equipment. Look for any signs of overheating or
evidence that objects might have entered the unit.

3) Ground Bond: Ensure that 25A DC can flow from exposed metal parts of the unit (not

BNC connector outers) to ground with an impedance of less than 100m.

4) Insulation Test: Connect the Live and Neutral of the power cable together and test the

insulation between this point and the ground at 500V DC. Readings greater than 1M are
acceptable.

9–2

9.3 Support and Service

In the event of difficulty, or apparent circuit malfunction, it is advisable to contact the service
department or your local sales engineer or agent (if overseas) for advice before attempting
repairs.

For repairs and recalibration it is recommended that the complete instrument be returned to one
of the following:

Asia

Microtest
14F-6, No.79, Hsin Tai Wu Road, Sec. 1,
Hsi-chih, Taipei 221, Taiwan, R.O.C.
Tel: [phone]
Fax: [phone]
Email: [e-mail]
When returning the instrument please ensure adequate care is taken with packing and arrange

insurance cover against transit damage or loss. If possible re-use the original packing box.