Keithley 182 User Manual

Model 182 Sensitive Digital Voltmeter

Quick Reference Guide

A GREATER MEASURE OF CONFIDENCE

INTRODUCTION

This quick reference guide includes summary information on front panel operation and IEEE-488 operation for the Model 182 Sensitive Digital Voltmeter . For detailed Model 182 information, consult the Model 182 Instruction Manual.

1990, Keithley Instruments, Inc.

Cleveland, Ohio, U.S.A.

Document Number: 182-903-01 Rev. B

TABLE OF CONTENTS

SAFETY PRECAUTIONS ....................................... 3

CONTROL SUMMARY ........................................... 8

TEST CONNECTIONS ......................................... 14

DEVICE DEPENDENT COMMANDS ................... 15

DATA FORMATS ................................................... 23

SRQ MASK AND SERIAL POLL BYTE................. 25

ALTERNATE OUTPUT WORD FORMATS........... 26

SAFETY PRECAUTIONS

The following safety precautions should be observed before using this product and any associated instrumentation. Although some instruments and accessories would normally be used with non-hazardous voltages, there are situations where hazardous conditions may be present.

This product is intended for use by qualified personnel who recognize shock hazards and are familiar with the safety precautions required to avoid possible injury. Read the operating information carefully before using the product.

The types of product users are: Responsible body is the individual or group respon-

sible for the use and maintenance of equipment, for ensuring that the equipment is operated within its specifications and operating limits, and for ensuring that operators are adequately trained.

Operators use the product for its intended function. They must be trained in electrical safety procedures and proper use of the instrument. They must be protected from electric shock and contact with hazardous live circuits.

Maintenance personnel perform routine procedures on the product to keep it operating, for example, setting the line voltage or replacing consumable materials. Maintenance procedures are described in the manual. The procedures explicitly state if the operator may perform them. Otherwise, they should be performed only by service personnel.

Service personnel are trained to work on live circuits, and perform safe installations and repairs of products.

Only properly trained service personnel may perform installation and service procedures.

Keithley products are designed for use with electrical signals that are rated Installation Category I and Installation Category II, as described in the International Electrotechnical Commission (IEC) Standard IEC

60664. Most measurement, control, and data I/O signals are Installation Category I and must not be directly connected to mains voltage or to voltage sources with high transient over-voltages. Installation Category II connections require protection for high transient overvoltages often associated with local AC mains connections. The user should assume all measurement, control, and data I/O connections are for connection to Category I sources unless otherwise marked or described in the Manual.

Exercise extreme caution when a shock hazard is present. Lethal voltage may be present on cable connector jacks or test fixtures. The American National Standards Institute (ANSI) states that a shock hazard exists when voltage levels greater than 30V RMS,

42.4V peak, or 60VDC are present. A good safety practice is to expect that hazardous voltage is present in any unknown circuit before measuring.

Users of this product must be protected from electric shock at all times. The responsible body must ensure that users are prevented access and/or insulated from every connection point. In some cases, connections must be exposed to potential human contact. Product users in these circumstances must be trained to protect themselves from the risk of electric shock. If the circuit is capable of operating at or above 1000 volts, no conductive part of the circuit may be exposed.

Do not connect switching cards directly to unlimited power circuits. They are intended to be used with impedance limited sources. NEVER connect switching cards directly to AC mains. When connecting sources to switching cards, install protective devices to limit fault current and voltage to the card.

Before operating an instrument, make sure the line cord is connected to a properly grounded power receptacle. Inspect the connecting cables, test leads, and jumpers for possible wear, cracks, or breaks before each use.

When installing equipment where access to the main power cord is restricted, such as rack mounting, a separate main input power disconnect device must be provided, in close proximity to the equipment and within easy reach of the operator.

For maximum safety, do not touch the product, test cables, or any other instruments while power is applied to the circuit under test. AL W A YS remove power from the entire test system and discharge any capacitors before: connecting or disconnecting cables or jumpers, installing or removing switching cards, or making internal changes, such as installing or removing jumpers.

Do not touch any object that could provide a current path to the common side of the circuit under test or power line (earth) ground. Always make measurements with dry hands while standing on a dry, insulated surface capable of withstanding the voltage being measured.

The instrument and accessories must be used in accordance with its specifications and operating instructions or the safety of the equipment may be impaired.

Do not exceed the maximum signal levels of the instruments and accessories, as defined in the specifications and operating information, and as shown on the instrument or test fixture panels, or switching card.

When fuses are used in a product, replace with same type and rating for continued protection against fire hazard.

Chassis connections must only be used as shield connections for measuring circuits, NOT as safety earth ground connections.

If you are using a test fixture, keep the lid closed while power is applied to the device under test. Safe operation requires the use of a lid interlock.

If a screw is present, connect it to safety earth ground using the wire recommended in the user documentation.

The symbol on an instrument indicates that the user should refer to the operating instructions located in the manual.

The symbol on an instrument shows that it can source or measure 1000 volts or more, including the combined effect of normal and common mode voltages. Use standard safety precautions to avoid personal contact with these voltages.

The WARNING heading in a manual explains dangers that might result in personal injury or death. Always read the associated information very carefully before performing the indicated procedure.

The CAUTION heading in a manual explains hazards that could damage the instrument. Such damage may invalidate the warranty.

Instrumentation and accessories shall not be connected to humans.

Before performing any maintenance, disconnect the line cord and all test cables.

To maintain protection from electric shock and fire, replacement components in mains circuits, including the power transformer, test leads, and input jacks, must be purchased from Keithley Instruments. Standard fuses, with applicable national safety approvals, may be used if the rating and type are the same. Other components that are not safety related may be purchased from other suppliers as long as they are equivalent to the original component. (Note that selected parts should be purchased only through Keithley Instruments to maintain accuracy and functionality of the product.) If you are unsure about the applicability of a replacement component, call a Keithley Instruments office for information.

T o clean an instrument, use a damp cloth or mild, water based cleaner. Clean the exterior of the instrument only. Do not apply cleaner directly to the instrument or allow liquids to enter or spill on the instrument. Products that consist of a circuit board with no case or chassis (e.g., data acquisition board for installation into a computer) should never require cleaning if handled according to instructions. If the board becomes contaminated and operation is affected, the board should be returned to the factory for proper cleaning/servicing.

CONTROL SUMMARY

RANGE

Use UP and DOWN to manually select desired measurement range; 3mV, 30mV, 300mV, 3V, or 30V. Present range is displayed on status line.

Press AUT O to turn auto-range on or off. Unit upranges at overflow point (±3,029,999 counts) and downranges at 9.33% of full range when AUTO is enabled.

Use FILTER to enable or disable both digital and analog filters simultaneously (actual filter configuration or response depends on MENU FILTER selections).

REL

Press REL READING to store current reading as baseline. Subsequent readings will be the difference between the applied signal and the stored baseline.

Press REL OUTPUT to store current analog output value as analog output baseline. Analog output value will be the difference between the normal, non-relative output value and the stored analog output baseline.

TRIG

Press SETUP to program TRIGGER MODE, TRIGGER SOURCE, TRIGGER DELAY, AND TRIGGER INTERVAL.

Use ▲ or ▼ to scroll through selections, ENTER to select, or ESC to cancel selection.

TRIGGER MODE: select multiple (continuous with one trigger) or one-shot (one reading per trigger).

TRIGGER SOURCE: select external, manual, disabled, or IEEE-488 X, GET or talk triggers.

TRIGGER DELAY: program desired trigger delay (time between trigger and reading in one-shot trigger mode): 0sec-

999.999sec. TRIGGER INTERVAL: program desired

trigger interval (time between individual readings in multiple trigger mode): 0.01 sec-999.999sec.

BUFFER

Use STORE to start/stop buffer data storage. Store size of 1-1024 selects linear buffer (storage stops when size limitation is reached); store size of 0 selects circular buffer (buffer wraps around and overwrites old data after 1024 readings are stored). Unit stores readings at programmed trigger interval in multiple trigger mode or one reading per trigger in one-shot trigger mode.

Press RECALL to access stored buffer readings and buffer statistics. Readings include buffer location and time stamp. Statistics include number of samples, buffer average, maximum, minimum, and standard deviation.

SELECTION

Use ▲ or ▼ to scroll through MENU, SETUP, and RECALL selections. Press ENTER to choose displayed selection and move down one menu level (where applicable). Press ESC to cancel displayed selection and move up one menu level (where applicable).

Use MENU to access operating modes summarized below.

MENU Message Description

FILTER Set digital filter response,

analog filter on/off

INTEGRATION Set A/D integration period TIME (3msec, line cycle, or

100msec)

DISPLAY Set display resolution to RESOLUTION 3 1/2, 4 1/2, 5 1/2, or 6 1/2

digits READING REL Program reading relative value OUTPUT Set analog output gain and

relative value SETUP Save user setup, recall user or

factory default setup SET IEEE Select IEEE-488 primary

ADDRESS address (0-30) CALIBRATE Display test, calibrate Model

182, configure analog output

for normal or source

Press LOCAL to cancel remote (REM on) when the instrument is used over the IEEE-488 bus. LOCAL will be locked out when the bus LLO command is in effect.

FACTORY DEFAULT CONDITIONS

Description Default State

Range 30V, auto-range off Reading relative Off, value =0V Analog Filter Off Digital Filter On, medium response Buffer Off, size = 0000 (wrap around) Analog Output Relative off, value: 0V, gain: 1.0,

normal output, source value

= 0V Primary Address 7 Integration Period Line cycle (16.67msec @ 60Hz,

20msec @ 50Hz) Display Resolution 6 1/2 digits Trigger Mode Multiple Trigger Source External (MANUAL key also

operative) Trigger Interval 0.25sec Trigger Delay 0sec Calibration Lock On (calibration locked)

NOTE: All listed operating states except buffer status, primary address, and calibration lock status can be saved as user configuration using MENU save user setup selection. Primary address can be saved using MENU SET IEEE ADDRESS selection.

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