Service Manuals, User Guides, Schematic Diagrams or docs for : Keithley 220_230 220_900_01C
<< Back | HomeMost service manuals and schematics are PDF files, so You will need Adobre Acrobat Reader to view : Acrobat Download Some of the files are DjVu format. Readers and resources available here : DjVu Resources
For the compressed files, most common are zip and rar. Please, extract files with Your favorite compression software ( WinZip, WinRAR ... ) before viewing. If a document has multiple parts, You should download all, before extracting.
Good luck. Repair on Your own risk. Make sure You know what You are doing.
Image preview - the first page of the document
>> Download 220_900_01C documenatation <<
Text preview - extract from the document
Model 220,230
Programming Manual
Contains IEEE Programming Information
WARRANTY
Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for a period of I year
from date of shipment.
Keithley Instruments, Inc. warrants the following items for 90 days from the date of shipment: probes, cables, rechargeable
batteries, diskettes, and documentation.
During the warranty period, we will, at our option, either repair or replace any product that proves to be defective.
To exercise this warranty, write or call your local Keithley representative, or contact Keithley headquarters in Cleveland, Ohio.
You will be given prompt assistance and return instructions. Send the product, transportation prepaid, to the indicated service
facility. Repairs will be made and the product returned, transportation prepaid. Repaired or replaced products are warranted for
the balance of the original warranty period, or at least 90 days.
LIMITATION OF WARRANTY
This warranty does not apply to defects resulting from product modification without Keithley's express written consent, or
misuse of any product or part. This warranty also does not apply to fuses, software, non-rechargeable batteries, damage from
battery leakage, or problems arising from normal wear or failure to follow instructions.
THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING ANY
IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. THE REMEDIES PRO-
VIDED HEREIN ARE BUYER'S SOLE AND EXCLUSIVE REMEDIES.
NEITHER KEITHLEY INSTRUMENTS, INC. NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR ANY DIRECT,
INDIRECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF ITS
INSTRUMENTS AND SOFTWARE EVEN IF KEITHLEY INSTRUMENTS, INC., HAS BEEN ADVISED IN ADVANCE
OF THE POSSIBILITY OF SUCH DAMAGES. SUCH EXCLUDED DAMAGES SHALL INCLUDE, BUT ARE NOT LIM-
ITED TO: COSTS OF REMOVAL AND INSTALLATION, LOSSES SUSTAINED AS THE RESULT OF INJURY TO ANY
PERSON, OR DAMAGE TO PROPERTY.
Keithley Instruments, Inc. l 28775 Aurora Road Cleveland, OH 44139 440-248-0400
l l l Fax: 440-248-6168 l http:Nwww.keithley.com
BELGIUM: Keithley Instruments B.V. Bergensesteenweg 709 * B-1600 Sint-Pieters-Leeuw* 02/363 00 40. Fax: 02/363 00 64
CHINA: Keithley Instruments China Yuan Chen Xin Building, Room 705 12Yumin Road, Dewi, Madian Beijing loo029 861@62022886
l l l Fax.: 861@62022892
l
FRANCE: Keithley Instruments Sari B.P. 60.3, alICe des Garays 91122 Palaiseau C&x * 01 64 53 20 20 * Fax: 01 60 I 1 77 26
l
GERMANY: Keithlev Instruments GmbH Lundsberger Strwe 65 D-821 10 Germering * 089/84 93 07-40 - Fax: 089/84 93 07-34
l
GREAT BRITAIN: Keith& Instruments Ltd The Minster l 58 Portman Road * Reading, Berkshire RG30 IEA * 01 IS-9 57 56 66 * Fax: 01 IS-9 59 64 69
INDIA: Keithley Instruments GmbH Flat 28. WILOCRISSA l 14. Rest House Crescent * Bangalore S60001 l 91-EO-509-1320121 -Fax: 91-80-509-1322
ITALY Keithley Instruments s.r.1. Viale S. Gimignano. 38 * 20146 Milano l 02/48 30 30 08 * Rx: 02/48 30 22 74
NETHERLANDS: Keithley Instruments B.V. Postbus 559 4200AN Gorinchem * 0183-635333 *Fax: 0183-630821
l
SWITZERLAND: Keithley Instruments SA Kriesbachsvasse 4 * 8600 Diibendorf*OI-821 94 44 Fax: 01-820 3081
l
TAIWAN: Keithley Instruments Taiwan 1 FI. 85 PO Ai Street * Hsinchu, Taiwan, R.O.C. - 886-3572-9077 * Fax: 886-3572-903
1 o/99
Model 220 Programmable Current Source
Model 230 Programmable Current Source
Programming Manual
01982, Keithley Instruments, Inc.
All rights reserved.
Cleveland, Ohio, U.S.A.
Third Printing, May 2000
Document Number: 220-900-01 Rev. C
SPECIFICATIONS
IEEE-488 BUS IMPLEMENTATION:
Multiline Commands: DCL, LLO, SDC, GET, GTL, UNT, UNL, SPE, SPD.
Uniline Commands: IFC, REN, EOI, SRQ, ATN.
Interface Functions: SHl, AHl, T6, TE6, L4, LH), SRl, RLl, PW, DCl, DTl, CO, El.
Internal Programmable Parameters: DISPLAY MODE, OUTPUT, Prefix (Data Format), EOl, SRQ (including mask for over limit), PROGRAM MODE,
Range, Trigger Mode, Terminator Character, Inputs (SOURCE, LIMIT, DWELL TIME, 106Point Memory Locations), Output Status, Digital Self Test.
Digital l/O Port: A separate I/O port consisting of four input and four output lines as well as common (IEEE4881 and + 5VDC. Outputs will drive one
TTL load. Inputs represent one TTL load. The 220/230 can be programmed to generate a "SRQ" upon any change in the four bit input data.
Mating connector supplied.
IEEE COMMAND GROUPS
ADDRESS COMMAND GROUP HANDSHAKE COMMAND GROUP
LISTEN: LAG = LISTEN ADDRESS GROUP DAC = DATA ACCEPTED
MLA = MY LISTEN ADDRESS RFD=READY FOR DATA
UNL= UNLISTEN DAV = DATA VALID
TALK: TAG =TALK ADDRESS GROUP UNIVERSAL COMMAND GROUP
MTA = MY TALK ADDRESS
ATN = ATTENTION
UNT = UNTALK
DCL= DEVICE CLEAR
OTA=OTHER TALK ADDRESS
IFC = INTERFACE CLEAR
ADDRESSED COMMAND GROUP LLO = LOCAL LOCKOUT
ACG = ADDRESSED COMMAND GROUP REN = REMOTE ENABLE
GET= GROUP EXECUTE TRIGGER SPD = SERIAL POLL DISABLE
GTL = GO TO LOCAL SPE = SERIAL POLL ENABLE
SDC = SELECTIVE DEVICE CLEAR END = EOI
STATUS COMMAND GROUP
RQS = REQUEST SERVICE
SRQ= SERIAL POLL REQUEST
STB = STATUS BYTE
DEVICE DEPENDENT COMMAND GROUP
Display: DO Source
Dl Limit R7 1mA (220)
D2 Dwell Time R8 1OmS (220)
D3 Memory Location R9 lOOmA (220)
Function: Fo Standby Trigger: TO Start On Talk
Fl Operate Tl Stop On Talk
Start On GET
Prefix: GO Location With Prefix
Stop On GET
(Data Format) Gl Location Without Prefix
T4 StartOnX
G2 Buffer Address With Prefix
T5 Stop On X
G3 Buffer Address Without Prefix
T6 Start On External Trigger
G4 Full Buffer With Prefix
3-7 Stop On External Trigger
G5 Full Buffer Without Prefix
Terminator: YIASCII) Any ASCII except capitals, numbers, + - /,.e
EOI: KO Send EOI
YILF) CR LF
Kl Send No EOI
YfCR) LF CR
SRQ: M(O-31) Disabled: IDDC or IDDCO: Over Limit: End of Y(DEL) None
Buffer;`End of Dwell Time; No Remote; Input
Inputs: Current Source (220); Current Limit (230)
Port Change
V Vottage Limit (220); Voltage Source (230)
Program: PO Single W Dwell Time
Pl Continuous B Buffer Address
P2 Step Memory Location
Range: RO Auto I/O Port: 0015) Set Output Control Bits
Rl 1nA (220); 100mV (230)
status: uo Status Word
R2 1OnA (220): 1V (230)
Ul I/O Port status
I?3 100nA (220); 1OV (230)
R4 14 (220); 1OOV (230) Digital Self Test: JO
R5 1ofi f220) Execute: X Execute Command
R6 100&A (220)
Safety Precautions
The following safety precautions should be observed before using Users of this product must bc protcctcd from electric shock at all
this product and any associated instrumentation. Although some in- times. The responsible body must ensure that users arc prevented
struments and accessories would normally be used with non-haz- access and/or insulated from every connection point. In some cases,
ardous voltages, there are situations where hazardous conditions connections must be exposed to potential human contact. Product
may be present. users in these circumstances must bc trained to protect thcmsclves
from the risk of electric shock. If the circuit is capable ofopcrating
This product is intended for use by qualified personnel who recog- at or above 1000 volts. no conductive part of the circuit may be
nize shock hazards and are familiar with the safety precautions re- exposed.
quired to avoid possible injury. Read the operating information
carefully before using the product. As described in the Intcmational Electrotechnical Commission
(IEC) Standard IEC 664, digital multimctcr measuring circuits
The types of product users are:
(e.g., Keithley Models I75A, 199,2000,2001, 2002. and 2010) arc
Responsible body is the individual or group responsible for the use Installation Category II. All other instruments' signal terminals arc
and maintenance of equipment, for ensuring that the equipment is Installation Category I and must not bc connected to mains.
operated within its specifications and operating limits, and for en-
suring that operators are adequately trained. Do not connect switching cards directly to unlimited power circuits.
They are intended to bc used with impedance limited sources.
Operators use the product for its intended function. They must be NEVER connect switching cards directly to AC mains. When con-
trained in electrical safety procedures and proper use of the instru- necting sources to switching cards, install protective devices to lim-
ment. They must be protected from electric shock and contact with it fault current and voltage to the card.
hazardous live circuits.
Before operating an instrument, make sure the line cord is conncct-
Maintenance personnel perform routine procedures on the product ed to a properly grounded power receptacle. Inspect the connecting
to keep it operating, for example, setting the line voltage or replac- cables, test leads, and jumpers for possible wear. cracks, or breaks
ing consumable materials. Maintenance procedures are described in before each use.
the manual. The procedures explicitly state if the operator may per-
form them. Otherwise, they should be performed only by service For maximum safety, do not touch the product, test cables. or any
personnel. other instruments while power is applied to the circuit under test.
ALWAYS remove power from the cntirc test system and discharge
Service personnel are trained to work on live circuits, and perform any capacitors before: connecting or disconnecting cables or jump-
safe installations and repairs of products. Only properly trained ser- ers, installing or removing switching cards, or making internal
vice personnel may perform installation and service procedures. changes, such as installing or removing jumpers.
Exercise extreme caution when a shock hazard is present. Lethal Do not touch any object that could provide a current path to the
voltage may be present on cable connectorjacks or test fixtures. The common side of the circuit under test or power line (earth) ground.
American National Standards Institute (ANSI) states that a shock Always make measurements with dry hands while standing on a
hazard exists when voltage levels greater than 30V RMS, 42.4V dry, insulated surface capable of withstanding the voltage being
peak, or 60VDC are present. A good safety practice is to expect measured.
that hazardous voltage is present in any unknown circuit before
measuring.
The instrument and accessories must be used in accordance with its The WARNING heading in a manual explains dangers that might
specifications and operating instructions or the safety of the equip- result in personal injury or death. Always read the associated infor-
ment may be impaired. mation very carefully before performing the indicated procedure.
Do not exceed the maximum signal levels of the instruments and ac- The CAUTION heading in a manual explains hazards that could
cessories, as defined in the specifications and operating informa- damage the instrument. Such damage may invalidate the warranty.
tion, and as shown on the instrument or test fixture panels, or
switching card. Instrumentation and accessories shall not bc conncctcd to humans.
When fuses are used in a product, replace with same type and rating Before performing any maintenance, disconnect the line cord and
for continued protection against fire hazard. all test cables.
To maintain protection from electric shock and fire, replacement
Chassis connections must only be used as shield connections fat
components in mains circuits, including the power transformer, test
measuring circuits, NOT as safety earth ground connections.
Icads. and input jacks, must be purchased from Keithlcy Instru-
ments. Standard fuses, with applicable national safety approvals,
If you are using a test fixture, keep the lid closed while power is ap-
may be used if the rating and type are the same. Other components
plied to the device under test. Safe operation requires the use of a
that are not safety related may bc purchased from other suppliers as
lid interlock.
long as they are equivalent to the original component. (Note that se-
lectcd parts should be purchased only through Keithley Instruments
Ifa@ screw is present, connect it to safety earth ground using the
to maintain accuracy and functionality of the product.) If you arc
wire recommended in the user documentation.
unsure about the applicability of a replacement component, call a
Keithley Instruments office for information.
The a ! symbol on an instrument indicates that the user should re-
fer to the operating instructions located in the manual.
To clean an instrument, use a damp cloth or mild. water based
cleaner. Clean the exterior of the instrument only. Do not apply
The A symbol on an instrument shows that it can source or mea-
cleaner directly to the instrument or allow liquids to enter or spill
sure 1000 volts or more, including the combined effect of normal
on the instrument. Products that consist of a circuit board with no
and common mode voltages. Use standard safety precautions to
case or chassis (e.g., data acquisition board for installation into a
avoid personal contact with these voltages.
computer) should never require cleaning if handled according to in-
structions. If the board becomes contaminated and operation is af-
fected, the board should be returned to the factory for proper
cleaning/servicing.
Rev. IO/99
TABLE OF CONTENTS
Paragraph Title Page
SECTION 1 - GENERAL INFORMATlON
1 .I introduction ................................................................................................................................................................................................... 1-l
1.2 Model 220 and 230 IEEE Interface Features.. .............................................................................................................................................. l-l
1.3 Warranty Information.. ................................................................................................................................................................................... l-l
1.4 Manual Addenda.. ......................................................................................................................................................................................... l-l
1.5 Safety Symbols and Terms ........................................................................................................................................................................... l-1
1.6 Using the Model 220/230 Programming Manual. .......................................................................................................................................... l-l
1.7 IEEE Specifications ....................................................................................................................................................................................... 1-l
SECTION 2 - AN OVERVIEW OF THE IEEE-488 BUS
2.1 Introduction ............................................................................................ . ...................................................................................................... 2-l
2.2 Bus Description.. ........................................................................................................................................................................................... 2-l
2.3 IEEE-488 Bus Lines.. .................................................................................................................................................................................... 2-l
2.3.1 Bus Management Lines ........................................................................................................................................................................ 2-l
2.3.2 Handshake Lines .................................................................................................................................................................................. 2-2
2.3.3 Data Lines ............................................................................................................................................................................................. 2-2
2.4 Bus Commands.. ........................................................................................................................................................................................... 2-3
2.4.1 Uniline Commands.. .............................................................................................................................................................................. 2-3
2.4.2 Universal Commands.. ......................................................................................................................................................................... 2-3
2.4.3 Addressed Commands ......................................................................................................................................................................... 2-3
2.4.4 Unaddressed Commands ..................................................................................................................................................................... 2-3
2.4.5 Device-Dependent Commands.. ........................................................................................................................................................... 2-3
2.5 Command Codes .......................................................................................................................................................................................... 2-4
2.6 Command Sequences .................................................................................................................................................................................. 2-4
2.6.1 Addressed Command Sequence.. ........................................................................................................................................................ 2-6
2.6.2 Universal Command Sequence ............................................................................................................................................................ 2-6
2.6.3 Device-Dependent Command Sequence ............................................................................................................................................. 2-6
SECTION 3 - SYSTEM CONFIGURATION
3.1 Introduction ................................................................................................................................................................................................... 3-1
3.2 Hardware Considerations.. ............................................................................................................................................................................ 3-1
3.2.1 Typical Systems .................................................................................................................................................................................... 3-l
3.2.2 Bus Connections .................................................................................................................................................................................. 3-l
3.2.3 Primary Address Selection ................................................................................................................................................................... 3-3
3.2.4 Digital I/O Port.. ..................................................................................................................................................................................... 3-4
3.3 Software Considerations.. ............................................................................................................................................................................. 3-4
3.3.1 Controller Interface Routines ................................................................................................................................................................ 3-4
3.3.2 HP-85 BASIC Statements.. ................................................................................................................................................................... 3-5
3.3.3 Interface Function Codes ...................................................................................................................................................................... 3-5
3.3.4 Model 220/230 Interface Commands. ................................................................................................................................................... 3-6
SECTION 4 - OPERATION
4.1 Introduction ................................................................................................................................................................................................... 4-l
4.2 General Bus Commands.. ............................................................................................................................................................................. 4-l
4.2.1 REN (Remote Enable) .......................................................................................................................................................................... 4-l
4.2.2 IFC (Interface Clear). ............................................................................................................................................................................. 4-l
4.2.3 LLO (Local Lockout). ............................................................................................................................................................................. 4-2
4.2.4 GTL (Go To Local). ................................................................................................................................................................................ 4-2
4.2.5 DCL (Device Clear). .............................................................................................................................................................................. 4-2
4.2.6 SDC (Selective Device Clear). .............................................................................................................................................................. 4-3
4.2.7 GET (Group Execute Trigger) ............................................................................................................................................................... 4-3
4.2.8 Serial Polling (SPE, SPD) ..................................................................................................................................................................... 4-3
4.3 Device-Dependent Command Programming ................................................................................................................................................ 4-4
4.3.1 Execute (X) ........................................................................................................................................................................................... 4-6
4.3.2 Display Mode (D) .................................................................................................................................................................................. 4-6
4.3.3 Inputs (I, V, W, L, B). .............................................................................................................................................................................. 4-6
4.3.4 I/O Port (0) ........................................................................................................................................................................................... 4-8
4.3.5 Function (F). .......................................................................................................................................................................................... 4-8
4.3.6 Data Format (G). ................................................................................................................................................................................... 4-8
4.3.7 EOI Programming (K) ........................................................................................................................................................................... 4-10
TABLE OF CONTENTS (CONT.)
Paragraph Title Page
4.3.8 SRQ Mode (M) and Status Byte Format.. ............................................................................................................................................. 4-10
4.3.9 Program Mode (P) ................................................................................................................................................................................ 4-13
4.3.10 Range (R) ............................................................................................................................................................................................. 4-13
4.3.11 Trigger Mode (T) ................................................................................................................................................................................... 4-14
4.3.12 Programmable Terminator (Y). .............................................................................................................................................................. 4-15
4.3.13 Status Word (U) .................................................................................................................................................................................... 4-15
4.3.14 Digital Self-Test (J). ............................................................................................................................................................................... 4-17
4.4 Front Panel Error Messages ......................................................................................................................................................................... 4-17
4.4.1 IDDC Error.. .......................................................................................................................................................................................... 4-18
4.4.2 IDDCO Error ......................................................................................................................................................................................... 4-18
4.4.3 No Remote Error.. ................................................................................................................................................................................. 4-18
4.5 Waveform Programs ...................................................................................................................................................................................... 4-18
4.5.1 Sine Wave Approximation ..................................................................................................................................................................... 4-18
4.5.2 Ramp Simulation.. ................................................................................................................................................................................. 4-19
SECTION 5 - IEEE COMMAND FLOW CHARTS
5.1 Introduction ................................................................................................................................................................................................... 5-1
5.2 DCL (Device Clear). ...................................................................................................................................................................................... 5-1
5.3 IFC (Interface Clear) ..................................................................................................................................................................................... 5-1
5.4 REN (Remote Enable) .................................................................................................................................................................................. 5-1
5.5 Serial Polling (SPE, SPD) ............................................................................................................................................................................. 5-2
5.6 UNL (Unlisten). .............................................................................................................................................................................................. 5-2
5.7 UNT (Untalk) ................................................................................................................................................................................................. 5-3
5.8 GET (Group Execute Trigger). ....................................................................................................................................................................... 5-3
5.9 GTL (Go To Local). ........................................................................................................................................................................................ 5-4
5.10 SPC (Selective Device Clear) ....................................................................................................................................................................... 5-4
5.11 Device-Dependent Commands.. ................................................................................................................................................................... 5-4
ii
LIST OF TABLES
Table Title Page
2-l IEEE-488 Bus Command Summary ............................................................................................................................................................. 2-4
2-2 Hexadecimal and Decimal Command Codes ............................................................................................................................................... 2-4
2-3 Typical Addressed Command Sequence ...................................................................................................................................................... 2-6
2-4 Typical Device-Dependent Command Sequence.. ........................................................................................................................................ 2-6
3-l IEEE Contact Designations.. ......................................................................................................................................................................... 3-2
3-2 Primary Address Switch Positions ................................................................................................................................................................ 3-3
3-3 Digital I/O Port Pin Assignments ................................................................................................................................................................... 3-4
3-4 HP-85 IEEE-488 Basic Statements .............................................................................................................................................................. 3-5
3-5 Model 220/230 Interface Function Codes ..................................................................................................................................................... 3-6
3-6 IEEE Command Groups ............................................................................................................................................................................... 3-6
4-1 General Bus Command.. ............................................................................................................................................................................... 4-l
4-2 Default Values (Status on Power Up and After SDC or DCL) ....................................................................................................................... 4-3
4-3 Device-Dependent Command Summary ...................................................................................................................................................... 4-5
4-4 Model 220 and 230 Display Mode Commands ............................................................................................................................................. 4-6
4-5 Input Command Summary ............................................................................................................................................................................ 4-7
4-6 l/O Port Command Parameters ..................................................................................................................................................................... 4-8
4-7 SRQ Commands and Conditions .................................................................................................................................................................. 4-11
4-8 Status Byte Data and Error Conditions. ........................................................................................................................................................ 4-12
4-9 Range Commands ........................................................................................................................................................................................ 4-13
4-10 I/O Port Status Values.. ................................................................................................................................................................................. 4-16
LIST OF FIGURES
Figure Title Page
2-l IEEE Bus Configuration ................................................................................................................................................................................ 2-2
2-2 IEEE Handshake Sequence.. ........................................................................................................................................................................ 2-2
2-3 Command Codes ......................................................................................................................................................................................... 2-5
3-1 System Types ................................................................................................................................................................................................ 3-l
3.2 IEEE-488 Connector.. ................................................................................................................................................................................... 3-l
3-3 IEEE-488 Connections.. ................................................................................................................................................................................ 3-2
3-4 Rear Panel of Model 220 or 230 Showing IEEE Connectors and Switches ................................................................................................. 3-2
3-5 Contact Assignments.. .................................................................................................................................................................................. 3-2
3-6 Typical IEEE-488 Bus Driver (One of 16). ..................................................................................................................................................... 3-3
3-7 Primary Address Switches (Address = 12 Shown) ....................................................................................................................................... 3-3
3-8 Digital I/O Port Pin Assignments.. ................................................................................................................................................................. 3-4
4-1 Model 220 and 230 Data Formats.. ............................................................................................................................................................... 4-9
4-2 SRQ Mask Format ........................................................................................................................................................................................ 4-12
4-3 Status Byte Format ....................................................................................................................................................................................... 4-12
4-4 Status Word Format (Default Values Shown) ................................................................................................................................................ 4-l 6
4-5 I/O Status Format (Default Values Shown). ................................................................................................................................................... 4-16
4-6 Front Panel Error Messages ......................................................................................................................................................................... 4-l 8
5-1 DCL Command Flow Chart ........................................................................................................................................................................... 5-l
5-2 IFC Command Flow Chart ............................................................................................................................................................................ 5-l
5-3 REN Command Flow Chart .......................................................................................................................................................................... 5-2
5-4 Serial Poll Flow Chart.. .................................................................................................................................................................................. 5-2
5-5 UNL Command Flow Chart.. ......................................................................................................................................................................... 5-3
5-6 UNT Command Flow Chart.. ......................................................................................................................................................................... 5-3
5-7 GET Command Flow Chart. .......................................................................................................................................................................... 5-4
5-8 GTL Command Flow Chart.. ......................................................................................................................................................................... 5-4
5-9 SDC Command Flow Chart .......................................................................................................................................................................... 5-5
5-10 Device-Dependent Command Flow Chart .................................................................................................................................................... 5-5
iii/iv
SECTION 1
GENERAL INFORMATION
1.1 INTRODUCTION may be found on an addendum included with this manual.
Be sure to review these changes before attempting to pro-
The Model 220 programmable current source, and the gram the instrument.
Model 230 programmable voltage source are each supplied
with a standard IEEE-488 interface. This interface adds an 1.5 SAFETY SYMBOLS AND TERMS
extra measure of versatility by allowing the transmission of
data and commands over the IEEE-488 bus. The built-in The following safety symbols and terms are used in this
IEEE interface provides all the logic necessary to interface manual and may be found on the Model 220 and 230:
the Models 220 and 230 to the bus using standard
IEEE-488-1978 protocol. Additionally, the interface board The symbol Q' on the instrument indicates that the
incorporates a separate digital I/O port that may be used to user should refer to the operating instructions.
interface the Models 220 and 230 to other digital instrumen-
tation. The symbol on the instrument indicates that a
potential of 1OOOV or more may be present on the
1.2 MODEL 220 AND 230 IEEE INTERFACE FEATURES terminal(s). Standard safety precautions should be observ-
ed when such dangerous voltages are encountered.
Important IEEE-488 interface features include:
1. IEEE-4881978 Standard. The Model 220 or 230 com- information associated with the WARNING heading ex-
municates with other instrumentation using the same plains dangers that could result in personal injury or death.
IEEE488-1978 standards.
2. Standard IEEE Connector. A standard IEEE-488 connec- Information following the CAUTION heading explains
tor is available on the rear panel of the instrument for hazards that could damage the instrument.
easy connection to the IEEE bus.
3. Simple Primary Address Selection. The primary address 1.6 USING THE MODEL 220/230 PROGRAMMING
of the Model 220 or 230 may be easily changed by using MANUAL
the five address switches on the rear panel of the instru-
ment. This manual contains all the information necessary to con-
4. Digital I/O port. The interface also includes a digital I/O nect the Model 220 or 230 to the IEEE488 bus and program
port which has separate 4-bit input and output connec- the instrument from a separate bus controller. Not included
tions. Port status may be read and controlled through in this manual is information concerning front panel opera-
commands given over the IEEE bus. tion, servicing, or maintenance of the instrument {including
5. Programming Versatility. All Model 220/230 operation is the interface board itself). For those aspects, refer to the
supported by IEEE programming. In addition, numerous Model 220 or 230 Instruction Manual.
other IEEE commands add operating features not avail-
able from the front panel. This programming manual is divided into the following
sections:
1.3 WARRANTY INFORMATION 1. Section 2 contains a general description of the IEEE-488
bus and its commands.
Warranty information may be found inside the front cover of 2. information necessary to connect the instrument to the
this manual. Should it become necessary to exercise the bus and set the primary address is contained in Section 3.
warranty, contact your nearest Keithley representative or Also, digital I/O port information can be found in this
the factory to determine the proper course of action. section.
Keithley Instruments, Inc. maintains service facilities in the 3. The bulk of the programming information may be found
United States, United Kingdom, and throughout Europe. in Section 4. General bus commands as well as com-
Addresses for these facilities may be found inside the front mands unique to the Models 220 and 230 are covered in
cover of this manual. Information concerning the applica- detail.
tion, operation, or service of your instrument may be 4. Section 5 contains IEEE command flow charts, which
directed to the applications engineer at any of these could be helpful in some applications.
locations.
1.7 IEEE SPECIFICATIONS
1.4 MANUAL ADDENDA
A complete list of IEEE specifications is presented immedi-
Information concerning improvements or changes to the ately preceding this section.
instrument which occur after the printing of this manual
l-1/1-2
SECTION 2
AN OVERVIEW OF THE IEEE-488 BUS
2.1 INTRODUCTDON Several devices may be commanded to listen at once, but
only one device may be a talker at any given time. Other-
The IEEE-488 bus is an instrumentation data bus adopted by wise, communications would be scrambled much like an
the IEEE WWitute of Electrical and Electronic Engineers) in individual's trying to pick out a single conversation out of a
1975 and given the IEEE488 designation. The most recent large crowd.
revision of bus standards was made in 1978; hence the com-
plete description for current bus standards is the Before a device can talk or listen, it must be appropriately
IEEE-488-1978 designation. addressed. Devices are selected on the basis of their primary
address; the addressed device is sent a talk or listen com-
This section gives a brief description of the general bus mand derived from its primary address. Normally, each
structure along with an outline of bus commands. The infor- device on the bus has a unique primary address so that each
mation presented here is not intended to be an in-depth may be addressed individually.
description of what is truly a very complex set of standards.
More complete information on the IEEE-488 bus, which is Once the device is addressed to talk or listen, appropriate
also frequently referred to as the GPIB (General Purpose bus transactions are set to take place. For example, if an
Interface Bus), is available from the IEEE and a variety of instrument is addressed to talk, it will usually place its data
other sources. on the bus one byte at a time. The listening device will then
read this information, and the appropriate software can then
2.2 BUS DESCRIPTION be used to channel the information to the desired location.
The IEEE-488 bus was designed as a parallel data transfer 2.3 IEEE-488 BUS LINES
medium to optimize data transfer without using an exces-
sive number of bus lines. In keeping with this goal, the bus The signal lines on the IEEE-488 bus are grouped into three
has only eight data lines that are used for both data and general categories. The data lines handle bus information,
some commands. Five bus management lines and three while the handshake and bus management lines ensure that
handshake lines round out the complement of signal lines. proper data transfer and bus operation takes place. Each of
Since the bus is of parallel design, all devices connected to the bus lines is active low so that approximately zero volts is
the bus have the same information available simultaneously. a logic one. The following paragraphs describe the purpose
Exactly what is done with the information by each device of these lines, which are shown in Figure 2-l.
depends on many factors, including device capabilities.
2.3.1 Bus Management Lines
A typical bus configuration for controlled operation is
shown in Figure 2-1. The typical system will have one con- The bus management group is made up of five signal-lines
troller and one or more instruments to which commands are that help ensure an orderly transfer of data. These lines are
given and, in most cases, from which data is received. used to send the uniline commands described in paragraph
Generally, there are three categories that describe device 2.4.
operation. These designations include: controller; talker:
listener. 1. ATN (Attention)-The ATN line is one of the more impor-
tant management lines. The state of the ATN line deter-
The controller does what its name implies: it controls other mines whether controller information on the data bus is to
devices on the bus. A talker sends data, while a listener be considered data or a multiline command as described
receives data. Depending on the instrument, a particular in paragraph 2.4.
device may be a talker only, a listener only, or both a talker 2. IFC (Interface Clear)-Setting the IFC line true (low)
and a listener. causes the bus to go to a known state by sending the IFC
command.
Any given system can have only one controller (control may 3. REN (Remote Enable)-Setting the REN line low sends
be passed to an appropriate device through a special com- the REN command. This sets up instruments on the bus
mand), but any number of talkers or listeners may be pre- for remote operation.
sent up to the hardware constraints of the bus. Generally, 4. EOI (End Or Identify)-The EOI line is used to send the
the bus is limited to 15 devices, but this number may be EOI command that usually terminates a multi-byte
reduced if higher than normal data transfer rates are transfer sequence.
required or if longer than normal cables are used. 5. SRQ (Service Request)-The SRQ line is set low by a
device when it requires service from the controller.
2-1
TO OTHER DEVICES
The complete handshake sequence for one data byte is
shown in Figure 2-2. Once data is on the bus, the source
checks to see that NRFD is high, indicating that all devices
on the bus are ready for data. At the same time NDAC
should be low from the previous byte transfer. If these con-
ditions are not met, the source must then wait until the
TALK.LISTEN.
NRFD and NDAC lines have the correct status. If the source
I AN0 dt5NTR0~
(COMPUTER) E is a controller, NRFD and NDAC must remain stable for at
DATA BUS least 100ns after ATN is set low. Because of the possibility
)
of bus hang up, some controllers have time-out routines to
l ◦ Jabse Service Manual Search 2024 ◦ Jabse Pravopis ◦ onTap.bg ◦ Other service manual resources online : Fixya ◦ eServiceinfo