Guildline 6560 User manual

TECHNICAL MANUAL
FOR
MODEL 6560
"RESISTANCE CALIBRATOR"
NOTICE
The contents and information contained in this manual are
proprietary to Guildline Instruments. They are to be used only as a
guide to the operation and maintenance of the equipment with
which this manual was issued and may not be duplicated or
transmitted by any means, either in whole or in part, without the
written consent of Guildline Instruments.
TM6560-J-00

i
TABLE OF CONTENTS
1INTRODUCTION 1
1.1 SCOPE ........................................................................................................................................ 1
1.2 GENERAL DESCRIPTION........................................................................................................... 1
2 SPECIFICATIONS..................................................................................................................................... 2
3 OPERATING INSTRUCTIONS................................................................................................................... 5
3.1 INSTALLATION ........................................................................................................................... 5
3.2 FRONT PANEL INDICATORS..................................................................................................... 5
3.2.1 DISPLAY WINDOW ........................................................................................ 5
3.2.2 GUARD INDICATOR...................................................................................... 7
3.2.3 CAL MODE INDICATOR................................................................................ 7
3.2.4 2-TERMINAL INDICATOR.............................................................................. 7
3.2.5 4-TERMINAL INDICATOR.............................................................................. 7
3.2.6 SRQ INDICATOR............................................................................................ 7
3.2.7 LISTEN INDICATOR ....................................................................................... 7
3.2.8 TALK INDICATOR .......................................................................................... 7
3.2.9 REMOTE INDICATOR..................................................................................... 7
3.2.10 LOCAL INDICATOR ...................................................................................... 8
3.3 FRONT PANEL CONTROLS........................................................................................................ 8
3.3.1 POWER SWITCH............................................................................................. 8
3.3.2 REMOTE LOCAL KEY..................................................................................... 8
3.3.3 GUARD KEY.................................................................................................... 8
3.3.4 RESET KEY ....................................................................................................... 8
3.3.5 CAL EDIT KEY................................................................................................. 8
3.3.6 CAL MODE KEY............................................................................................. 9
3.3.7 2-TERMINAL KEY ........................................................................................... 9
3.3.8 4-TERMINAL KEY............................................................................................ 9
3.3.9 ↓kΩKEY.......................................................................................................... 9
3.3.10 ↑MΩKEY ........................................................................................................ 9
3.3.11 0-9 DIGIT KEYS............................................................................................... 9
3.3.12 ENTER KEY ..................................................................................................... 10
3.3.13 BACK SPACE KEY......................................................................................... 10
3.4 REAR PANEL CONTROLS......................................................................................................... 10
3.4.1 VOLTAGE SELECTION DRUM....................................................................... 10
3.4.2 GPIB ADDRESS SWITCHES........................................................................... 13
3.4.3 NORMAL/CAL KEY SWITCH........................................................................ 15
3.5 FRONT PANEL CONNECTORS................................................................................................. 15
3.5.1 C1- CURRENT TERMINAL 1.......................................................................... 17
3.5.2 C2- CURRENT TERMINAL 2.......................................................................... 17
3.5.3 P1- POTENTIAL TERMINAL 1........................................................................ 17
3.5.4 P2- POTENTIAL TERMINAL 2........................................................................ 18
3.5.5 GUARD TERMINAL........................................................................................ 18
3.5.6 GND - GROUND TERMINAL........................................................................ 18
3.6 REAR PANEL CONNECTORS................................................................................................... 18

ii
3.6.1 GPIB DATA CONNECTOR ........................................................................... 18
3.6.2 POWER INLET CONNECTOR........................................................................ 18
3.7 SELECTING A RESISTANCE...................................................................................................... 18
3.8 CHANGING CALIBRATION COEFFICIENTS .......................................................................... 18
4 REMOTE CONTROL................................................................................................................................. 20
4.1 GPIB INTERFACE....................................................................................................................... 20
4.1.2 GPIB OUTPUT BUFFERING............................................................................ 23
4.1.3 GPIB DEADLOCK.......................................................................................... 23
4.1.4 GPIB DEVICE CLEAR.................................................................................... 23
4.1.5 GPIB DEVICE TRIGGER ................................................................................ 23
4.1.6 REMOTE AND LOCAL OPERATION............................................................. 23
4.1.7 UNRECOGNIZED GPIB COMMANDS ........................................................ 25
4.1.8 GPIB COMMAND PARSER .......................................................................... 25
4.1.9 GPIB END OF MESSAGE TERMINATOR...................................................... 25
4.2 GPIB COMMANDS................................................................................................................... 26
4.2.1 *ESE - SET EVENTS ENABLE REGISTER......................................................... 26
4.2.2 *ESE? - EVENT STATUS ENABLE QUERY...................................................... 26
4.2.3 *ESR? - EVENT STATUS REGISTER QUERY................................................... 26
4.2.4 *IDN? - IDENTIFICATION QUERY................................................................ 29
4.2.5 *OPC - OPERATION COMPLETE................................................................. 29
4.2.6 *OPC? - OPERATION COMPLETE QUERY.................................................. 29
4.2.7 *OPT? - REPORT AVAILABLE OPTIONS...................................................... 29
4.2.8 *RST - DEVICE RESET..................................................................................... 30
4.2.9 *SRE - SERVICE REQUEST ENABLE COMMAND........................................ 30
4.2.10 *SRE? - SERVICE REQUEST ENABLE QUERY............................................... 31
4.2.11 *STB? - READ STATUS BYTE QUERY............................................................. 31
4.2.12 *TRG - GROUP EXECUTE TRIGGER............................................................. 31
4.2.13 CAL? - DISPLAY THE DATE OF THE LAST CALIBRATION........................... 31
4.2.14 DATE - SET THE SYSTEM DATE...................................................................... 33
4.2.15 DATE? - DISPLAY THE 6560 INTERNAL DATE............................................. 33
4.2.16 KEY? REPORT LAST KEY PRESSED................................................................ 33
4.2.17 KEY <KEYNAME> ENTER A KEYSTROKE..................................................... 34
4.2.18 OPTIONS? - DISPLAY THE OPTION SWITCH SETTINGS............................. 35
4.2.19 RESISTOR - SELECT A RESISTOR................................................................... 35
4.2.20 RESISTOR? - DISPLAY THE CURRENTLY SELECTED RESISTOR .................. 36
4.2.21 ROMCHECKSUM? - DISPLAY THE ROM CHECKSUM............................... 36
4.2.22 SINCE? - DISPLAY THE TIME THE 6560 WAS LAST RESET ......................... 37
4.2.23 SERIALNUMBER - SET THE 6560 SERIAL NUMBER...................................... 37
4.2.24 SOFCALTM - SET CALIBRATION COEFFICIENTS......................................... 37
4.2.25 SOFCAL? - EXAMINE CALIBRATION COEFFICIENTS............................... 38
4.2.26 TERSE - TURN OFF VERBOSE MODE............................................................ 39
4.2.27 TIME - SET THE TIME SYSTEM........................................................................ 39
4.2.28 TIME? - DISPLAY THE SYSTEM TIME............................................................. 39
4.2.29 TIMEZONE - SET THE OPERATIONAL TIMEZONE........................................ 39
4.2.30 UPTIME? - DISPLAY HOW LONG THE 6560 HAS BEEN RUNNING........... 40
4.2.31 VERBOSE - SET VERBOSE MODE................................................................. 40
4.3 PROGRAMMING HINTS........................................................................................................... 40
5 OPTIONS.................................................................................................................................................. 41
5.1 DIP SWITCHES........................................................................................................................... 41

iii
5.1.1 OPTION SWITCHES 1 TO 4 - RESERVED...................................................... 41
5.1.2 OPTION SWITCH 5 - 50/60 Hz SELECT ....................................................... 42
5.1.3 OPTION SWITCH 6 - LAST RESISTANCE...................................................... 42
5.1.4 OPTION SWITCH 7 - OPEN/SHORT............................................................. 42
5.1.5 OPTION SWITCH 8 - FACTORY CALIBRATION.......................................... 42
6 SPECIFICATION VERIFICATION............................................................................................................ 44
6.1 ULTIMATE SPECIFICATIONS..................................................................................................... 44
6.1.1 EQUIPMENT REQUIRED .............................................................................................. 44
6.2 RESISTANCE MEASUREMENT WITH A 9975 CURRENT COMPARATOR .............................. 45
6.2.1 10 kΩAND BELOW ...................................................................................... 45
6.2.2 19 kΩAND 100 kΩ...................................................................................... 49
6.2.3 ABOVE 100 kΩ............................................................................................. 53
6.3 BASIC SPECIFICATIONS.......................................................................................................... 57
6.4 COMPUTING RESISTANCE VALUES........................................................................................ 57
7 PRINCIPLES OF OPERATION ................................................................................................................. 58
7.1 INTRODUCTION........................................................................................................................ 58
7.2 POWER SUPPLY......................................................................................................................... 58
7.3 CONTROL pcb.......................................................................................................................... 58
7.3.1 POWER AND CONTROL............................................................................... 59
7.3.2 CENTRAL PROCESSING UNIT...................................................................... 59
7.3.3 MEMORY....................................................................................................... 61
7.3.4 SERIAL INTERFACES (OPTIONAL) ............................................................... 61
7.3.5 KEYBOARD INTERFACES.............................................................................. 62
7.3.6 CHART RECORDER OUTPUT (OPTIONAL).................................................. 62
7.3.7 GPIB INTERFACE........................................................................................... 63
7.4 FRONT PANEL pcb................................................................................................................... 63
7.4.1 VACUUM-FLUORESCENT DISPLAY............................................................. 63
7.4.2 KEYBOARD.................................................................................................... 63
7.4.3 LIGHT EMITTING DIODES ............................................................................. 64
7.4.4 DISPLAY TO RESISTOR pcb INTERFACE..................................................... 64
7.5 RESISTOR/RELAY pcb.............................................................................................................. 64
7.6 SOFTWARE................................................................................................................................. 65
8 TROUBLESHOOTING AND MAINTENANCE......................................................................................... 66
8.1 TROUBLESHOOTING................................................................................................................. 66
8.2 SOFTWARE DIAGNOSTICS...................................................................................................... 66
8.2.1 SETTING THE INTERNAL REAL TIME CLOCK............................................... 67
8.2.2 CHECKING THE ROM CHECKSUM............................................................. 67
8.2.3 TESTING THE NON-VOLATILE MEMORY (EEROM).................................... 67
8.2.4 TESTING THE RELAY DRIVERS ...................................................................... 68
8.2.5 TESTING THE DISPLAY................................................................................... 68
8.2.6 TESTING THE GPIB SWITCHES...................................................................... 69
8.2.7 DISPLAYING THE DATE CALIBRATION....................................................... 69
8.2.8 SETTING THE INSTRUMENT SERIAL NUMBER .............................................. 69
8.3 PREVENTATIVE MAINTENANCE.............................................................................................. 69
9 PARTS LISTS.............................................................................................................................................. 71

iv
10 DRAWINGS ............................................................................................................................................. 72

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LIST OF FIGURES
Figure 3.1: Keyboard and Display.............................................................................................. 6
Figure 3.2: Rear Panel.................................................................................................................. 11
Figure 3.3: Opening the Power Receptacle .......................................................................... 12
Figure 3.4: Switch Settings........................................................................................................... 14
Figure 3.5: Ideal Circuit................................................................................................................ 15
Figure 3.6: Functional Circuit...................................................................................................... 16
Figure 3.7: Leakage Circuit......................................................................................................... 17
Figure 4.1: Event Status Bit Operation ...................................................................................... 27
Figure 5.1: Location of Option Switch on Control PCB......................................................... 41
Figure 6.1: 9975 Current Comparator ...................................................................................... 45
Figure 6.2: 9975 Current Comparator connections for measurement of
resistances up to 10 kΩ............................................................................................ 46
Figure 6.3: 9975 Current Comparator connections for measurement of
resistances between 19 kΩand 100 kΩ............................................................... 50
Figure 6.4.: 9975 Current Comparator connections for measurement of
resistances greater than 100 kΩ............................................................................ 54

vi
LIST OF TABLES
Table 2.1: Basic Instrument Specifications..................................................................................................... 2
Table 2.2: Resistance Specifications (4-wire Mode) .................................................................................... 4
Table 3.1: Recommended Fuses.................................................................................................................... 12
Table 3.2: Line Cord Wiring............................................................................................................................... 13
Table 3.3: GPIB Mode Switches....................................................................................................................... 14
Table 4.1: IEEE-488.1 Pin Designations............................................................................................................ 21
Table 4.2: GPIB Device Capabilities............................................................................................................... 22
Table 4.3: Remote/Local State Transitions.................................................................................................... 25
Table 4.4: Event Status Register....................................................................................................................... 28
Table 4.5: Status Byte Register......................................................................................................................... 32
Table 4.6: Keyboard Character Designations.............................................................................................. 34
Table 5.1: Option Switches............................................................................................................................... 43
Table 6.1: CURRENT IxmA to Applied Voltage Conversion....................................................................... 52

1
1 INTRODUCTION
1.1 SCOPE
This manual contains technical specifications, detailed description and maintenance information
and diagrams for the Guildline Instrument's 6560 Resistance Calibrator.
1.2 GENERAL DESCRIPTION
The 6560 Resistance Calibrator provides a wide range of high precision resistors selected for use in
calibrating ohm-meters. All of the resistors may be selected under remote control from the GPIB
interface, this is especially useful in automated calibration setups.
Uses for the 6560 Resistance Calibrator include:
• Maintaining a set of precision reference resistors.
• Automatic calibration of precision resistance measurement apparatus.
• Providing an easy to use resistance standard.
In addition to the front panel manual controls, the Resistance Calibrator can be controlled from a
GPIB (IEEE-488) bus interface. Remote control commands include monitoring the current resistance
as well as selecting alternate resistances.

2
2 SPECIFICATIONS
┌
─────────────────────────────────────────
─
─
───────────
┐
│Specifications for Guildline Instruments │
│6560 Resistance Calibrator │
╞══════════════╤══════════════════════════╤════════════╡
│Operating │23 ± 5 │°C │
│├──────────────────────────┼────────────┤
│Temperature │70 ± 8 │°F │
├──────────────┼──────────────────────────┼────────────┤
│Operating │││
│Humidity │< 70% │R.H. │
├──────────────┼──────────────────────────┼────────────┤
│Power │││
│Requirements │50 │Volt Amps │
├──────────────┼──────────────────────────┼────────────┤
│Voltage │││
│Requirements │100,120, 220, 240 ± 10% │VAC 50/60 Hz│
├──────────────┼──────────────────────────┼────────────┤
│Dimensions │44.2 X 45.7 X 8.9 high │cm │
│├──────────────────────────┼────────────┤
││17.4 X 18 X 3.5 high │in │
├──────────────┼──────────────────────────┼────────────┤
│Weight │11 │kg │
│├──────────────────────────┼────────────┤
││25 │lbs │
└──────────────┴──────────────────────────┴────────────┘
Table 2.1: Basic Instrument Specifications

3
Other features include:
• Bench top mounting or rack mount with extra flanges provided separately.
• Hidden voltage selection switch on rear panel.
• GPIB Bus Address selectable from rear panel.
Each resistance element will be within 0.1% of the nominal value. The actual resistance values will
be displayed on the instrument's front panel readout with an uncertainty which is the sum of the
following:
1. the uncertainty of the original calibration.
2. the error due to the stability of the resistance element and the time elapsed from the date
of last calibration.
3. the product of the temperature coefficient (the fourth column of Table 2.2) and the
change in ambient temperature from the temperature at which the instrument was
calibrated.
The computation of total uncertainty is based on the following assumptions:
1. the relative humidity of the environment is <70% and the instrument has been in a
controlled environment for at least 72 hours.
2. the resistance elements have not been stressed beyond their maximum current ratings at
any time since calibration.
3. the resistance elements have not been stressed by large changes in their ambient
conditions (temperature and humidity) at any time since calibration.

4
Resistance Specifications (4-wire mode) for
Guildline Instruments 6560 Resistance Calibrator
Nominal
Value
(Ω)
Stability1(23°C ±2 K) TC/K2
(±ppm) Maximum Current
(mA)
24 Hrs
(±ppm) 90 Days (±ppm) 1 Yr (±ppm)
Short 0303030 500
1.0 10 70 100 6 400
1.9 9 65 90 6 300
10.0 4 25 30 2.5 100
19.0 3 20 30 2.5 100
100.0 1 10 15 1.5 25
190.0 1 10 15 1.5 25
1.0 k 1 8 10 1.5 10
1.9 k 1 8 10 1.5 10
10.0 k 1 8 10 1.5 2.5
19.0 k 1 8 10 1.5 2.5
100.0 k 1 8 10 1.5 0.5
190.0 k 1 8 10 1.5 0.25
1.0 M 2 10 15 1.5 0.05
1.9 M 3 10 15 1.5 0.025
10.0 M 6 25 50 3 0.005
19.0 M 6 25 50 4 0.005
100.0 M 14 110 150 10 0.005
Open4
1Does not include uncertainty of calibration.
2Add Temperature Coefficient (TC) to stability specification
30.1 mΩmaximum resistance.
4Maximum Voltage 500 Volts.
Table 2.2: Resistance Specifications (4-wire Mode)

5
3 OPERATING INSTRUCTIONS
3.1 INSTALLATION
Place the Resistance Calibrator on a solid bench. Where the Resistance Calibrator is to be used in
a rack, attach the mounting brackets provided. "To attach the rackmounting flanges (brackets),
the original screws holding the handles to the instrument are removed and the flanges attached
over the handles with the longer screws supplied. The instrument has to be supported in the
rack/cabinet with adjustable support angles or a support bar. In case of interference with other
equipment mounted directly below the instrument, the 4 feet must be removed. This requires that
the bottom skin of the instrument is lowered to get access to the nuts which hold the feet." Install
the unit in the rack.
Refer to Section 3.4.1 for proper line voltage selection. Connect the line cord to an electrical
outlet. Press POWER push button and observe that the display shows the currently selected
resistance (after displaying the status of the power on self tests).
Connect the resistance measuring device to the four front panel terminals (P1, C1, P2, C2and
optionally GUARD and GND).
WARNING
For best performance the P1and C1terminals should always be at a potential approximately equal
to the potential at the GND (ground) terminal. When measuring resistances above 190kΩthe P2
and C2terminals should have the high potential applied to them, if the guard circuit is used the
GUARD terminal should be tied to a potential source the same as the potential applied at the C2
terminal (the GUARD terminal is often tied to the C2terminal).
3.2 FRONT PANEL INDICATORS
There are numerous visual indicators on the front panel of the 6560. These indicators display the
value and status of the currently selected resistance, the status of the guard circuits, and the status
of the remote interface.
3.2.1 DISPLAY WINDOW
A sixteen-digit vacuum-fluorescent display shows either the actual value of the resistance
selected or the value of the number being entered from the keyboard. After power on or
reset the display will first light up all segments then light up all segments of each of the
sixteen display digits sequentially from left to right.

6
Figure 3.1: Keyboard and Display

7
3.2.2 GUARD INDICATOR
A red LED indicates that the guard circuit is currently enabled.
3.2.3 CAL MODE INDICATOR
A red LED indicates that the instrument is currently in the calibration mode. Great care
should be exercised in this mode since the stored value of any resistor may be easily
modified in this mode. It is not possible to enter this mode if the keyswitch on the rear panel
is in the NORMAL position.
3.2.4 2-TERMINAL INDICATOR
A red LED indicates that values displayed on the front panel of the instrument are for
measurements taken in a two-wire configuration.
3.2.5 4-TERMINAL INDICATOR
A red LED indicates that values displayed on the front panel of the instrument are for
measurements taken in a four-wire configuration.
3.2.6 SRQ INDICATOR
A red LED indicates that the 6560 is requesting service from the remote-control bus (Service
ReQuest). See Section 4.2.9 for a description of the service request enable command.
3.2.7 LISTEN INDICATOR
A red LED indicates that the 6560 is receiving data from the remote control interface
(GPIB). When the instrument is controlled from the GPIB interface the LISTEN indicator is lit
when the interface is addressed as the listener (listener active state) and extinguished
when the remote controller unaddresses the 6560.
3.2.8 TALK INDICATOR
A red LED indicates that the 6560 is sending data to the remote control interface (GPIB).
When the 6560 is controlled from the GPIB interface the TALK indicator is lit when the
interface is addressed as the talker (talker active state) and extinguished when the remote
controller unaddresses the 6560.
3.2.9 REMOTE INDICATOR
A red LED indicates that the 6560 has received commands from the remote interface
(GPIB) within the last minute. The LED is extinguished if no commands have been received
over a period of one (1) minute.

8
3.2.10 LOCAL INDICATOR
A red LED indicates that the instrument keyboard is enabled (i.e. it is possible to control the
instrument from the keyboard). When the indicator is extinguished all of the keys on the
keyboard (except the REMOTE/LOCAL key, see Section 3.3.2) are disabled.
3.3 FRONT PANEL CONTROLS
The controls on the front panel consist of an alternate action power switch and twenty-two
momentary push buttons mounted in the front panel membrane. Some of the membrane push
buttons have integral LED indicators.
3.3.1 POWER SWITCH
Connects AC power to the 6560 when depressed.
3.3.2 REMOTE LOCAL KEY
This key will return local control when pressed and extinguish the remote red Led indicator
unless the remote controller has disabled the entire keyboard.
When the LOCAL red LED indicator is lit the other keys on the keyboard will be enabled.
3.3.3 GUARD KEY
The guard key alternately enables and disables the guard circuit, the guard LED (see
Section 3.2.2) will be extinguished when the guard circuit is disabled.
3.3.4 RESET KEY
When this key is pressed the microprocessor performs a complete reset. Normally it is only
necessary to enter this sequence after the GPIB address has been changed.
3.3.5 CAL EDIT KEY
When the instrument is not in CAL mode (see Section 3.3.6) this key alternately changes the
display so that resistance is displayed to the nearest tenth of a part per million or the
nearest part per million.
When the instrument is in CAL MODE mode pressing this key will cause the instrument to
flash the current resistance value, prompting the user to enter a new value which will be
permanently stored in the instruments memory. Pressing the key a second time will cancel
the flashing . It is not possible to enter this mode unless the instrument is in calibration mode
(see Section 3.3.6)

9
3.3.6 CAL MODE KEY
When this key is pressed the instrument will alternately enter or exit CAL MODE. It is not
possible to enter CAL MODE unless the key switch on the rear panel is set to the CAL
position.
When the instrument is in CAL MODE all controls and indicators operate normally and the
CAL EDIT key is made operative.
3.3.7 2-TERMINAL KEY
Pressing the 2-TERMINAL key causes the instrument to display the value of the currently
selected resistor as if it were measured by a two-terminal ohmmeter. In CAL MODE if the
two-terminal mode is selected then any values entered will be stored in the two-terminal
coefficient table, the four-terminal coefficient will not be affected.
3.3.8 4-TERMINAL KEY
Pressing the 4-TERMINAL key causes the instrument to display the value of the currently
selected resistor as if it were measured by a four-terminal ohmmeter. This does not affect
the actual resistance. In CAL MODE if the 4-terminal mode is selected then any values
entered will be stored in the 4-terminal coefficient table, the two-terminal coefficient will
not be affected.
3.3.9 ¯kWKEY
Pressing the ↓kΩKey when the instrument is displaying a resistance value will cause the
instrument to select the next lower resistance. After the resistance has been lowered to
zero Ωfurther pressing of this key will have no effect.
When a number is being entered pressing this key will add a K suffix, effectively multiplying
the entered value by 1 000.
3.3.10 -MWKEY
Pressing the ↑MΩKey when the instrument is displaying a resistance value will cause the
instrument to select the next higher resistance. After the resistance has been raised to
open circuit further pressing of this key will have no effect.
When a number is being entered pressing this key will add an M suffix, effectively
multiplying the entered value by 1 000 000.
3.3.11 0-9 DIGIT KEYS
Used to select the required resistance or to enter the value of a calibration coefficient.
Press to enter numbers 0 through 9.

10
3.3.12 ENTER KEY
This key is pressed after the required resistance has been entered. After the Enter Key has
been pressed the instrument will select the closest available resistance.
3.3.13 BACK SPACE KEY
This key can be pressed during the entry of a resistance or a calibration coefficient, the last
key stroke will be deleted. If all key strokes are deleted the display will revert to the previous
display mode.
3.4 REAR PANEL CONTROLS
The rear panel (Figure 3.2) of the instrument has a number of controls which are used to configure
the input line voltage, configure the GPIB bus and to enable instrument calibration.
3.4.1 VOLTAGE SELECTION DRUM
This drum allows the 6560 operator to select the input voltage of the instrument from one of
100, 120, 220, or 240 volts. It is important that the correct input voltage be selected before
any attempt is made to operate the instrument. To change the selected input voltage,
after removing the line cord from the receptacle, pry open the power receptacle as
shown in Figure 3.3.

11

12
Check to see that the fuses inserted in the receptacle correspond to the type specified in
Table 3.1. Only fuses of the specified type should be used.
In order to rotate the drum it must be removed completely from the receptacle. Set the
voltage selector drum so that the proper line voltage indication will be visible through the
receptacle window when the cover is closed.
F
igure 3.3: Opening the Power Receptacle
┌
──────────
┬
────────────────
┐
│LINE │FUSE TYPE │
│VOLTAGE │REQUIRED │
╞══════════╪════════════════╡
│100 Volts │½ Amp Slo-Blo │
│120 Volts │(MDL-½ A 250 V)│
├──────────┼────────────────┤
│220 Volts │¼ Amp Slo-Blo │
│240 Volts │(MDL-¼ A 250 V)│
└──────────┴────────────────┘
T
able 3.1: Recommended Fuses

13
Where the supplied line cord does not match the power outlet receptacle the plug may
be removed from the line cord and replaced with a 3-pin plug of the correct type. The
plug should be wired as shown in Table 3.2.
3.4.2 GPIB ADDRESS SWITCHES
The GPIB address and mode is set through the switches on the rear panel (Figure 3.4).
Switches 1 through 5 set the address, in order to compute the address use Equation 1
where Snis either 1 or 0 depending upon the position of switch n. When a switch is in the
open position it is a 1, when a switch is closed it is a 0.
address = S120+ S221+ S322+ S423+ S524(1)
The GPIB mode (disabled, talk-only, or talk/listen) is set by switches 6 and 7, the possible
settings for the switches are shown in Table 3.3. The 6560 does not support the talk-only, or
listen-only modes, the modes are available only for consistency with other instruments
manufactured by Guildline.
The last switch (S8) enables or disables the audible feed back when a key is pressed. If S8is
in the 1 position then as any key is pressed the instrument will "beep", if S8is in the 0 position
then the instrument will not "beep" when a key is pressed.
Since the membrane keys on the 6560 have no tactile feel it is often difficult for an
instrument operator to be sure that a key has been activated when the audible feedback
is disabled. For this reason it is recommended that the audible feedback always be
enabled.
It is not possible to disable the audible "beep" emitted from the instrument during power on
diagnostics and error notifications.
╒
══════════════
╤
════════════════
╕
│CODE WIRE │POTENTIAL │
│COLOUR │VOLTAGE │
╞══════════════╪════════════════╡
│Brown │High Voltage │
├──────────────┼────────────────┤
│Blue │Neutral │
├──────────────┼────────────────┤
│Green/Yellow │Ground (Earth) │
└──────────────┴────────────────┘
Table 3.2: Line Cord Wiring