Guildline 6564 User manual

TECHNICAL MANUAL
FOR
MODEL 6564
HIGH RESISTANCE SCANNER
NOTICE
The contents and information contained in this manual are proprietary to Guildline
Instruments Limited. 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
permission of Guildline Instruments Limited.
TM6564-C-00
26 April, 2011

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i
WARRANTY AND SERVICE
CERTIFICATION: Guildline Instrument Limited certifies that this product was tested
and inspected and found to meet its published specifications when it was shipped from
the factory.
WARRANTY: This product is warranted against defects in materials and workmanship
for a period of one year from date of shipment. During the warranty period, Guildline
Instrument Limited will, at its option, either repair or replace products that prove to be
defective.
SERVICE: For warranty service or repair, this product must be returned to the factory.
The buyer shall prepay shipping charges to Guildline Instrument Limited and Guildline
Instrument Limited shall pay surface shipping to the buyer. Permission must be obtained
from the factory for warranty repair returns.
LIMITATIONS: The foregoing warranty shall not apply to defects resulting from
improper or inadequate maintenance by the buyer, or unauthorized modifications or
misuse.
Neither Guildline Instrument Limited nor any of its employees shall be liable for any
direct or indirect, special, incidental or consequential damages arising out of the use of
this product.
No other warranty is expressed or implied.
SAFETY PRECAUTIONS
This product has been designed and tested in accordance with IEC1010-1/EN61010-1
including amendment 1(1995) for insulation category II use. Use of this equipment in a
manner not specified could result in personal injury.
AC POWER SOURCE: This product is intended to operate from an ac power source
that will apply not more than 264 V ac between either of the supply conductors and
ground.
POWER CORD: Use only the power cord and connector appropriate for the voltage and
plug configuration in your country. The cord must contain a safety ground conductor and
be connected to a plug that has a connection to earth ground. Use only a power cord that
is in good condition.
SIGNAL INPUT POWER: Signals applied to the input or output terminals must be
limited to levels deemed safe by the IEC/EN specifications. When applied voltages are
above 30 volts, the current source must limit the current to not more than 2 milliamps.

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ii
TABLE OF CONTENTS
1. INTRODUCTION .................................................................................................. 1-1
1.1. DESCRIPTION.....................................................................................................................................1-1
1.2. SPECIFICATIONS...............................................................................................................................1-2
1.3. REAR PANEL CONNECTIONS.........................................................................................................1-3
1.4. REFERENCE STANDARD PROTECTION SYSTEMS..................................................................1-3
2. INSTALLATION ................................................................................................... 2-1
2.1. INITIAL INSPECTION .......................................................................................................................2-1
2.2. POWER REQUIREMENTS................................................................................................................2-1
2.3. LOCATION ...........................................................................................................................................2-1
3. OPERATION ........................................................................................................ 3-1
3.1. FRONT PANEL CONTROLS AND INDICATORS .........................................................................3-1
3.2. REAR PANEL CONNECTIONS.........................................................................................................3-2
3.3. FRONT PANEL OPERATION ...........................................................................................................3-3
3.4. ADDRESS SELECTION......................................................................................................................3-3
3.5. OPERATION FROM INTERFACE BUS...........................................................................................3-5
3.6. SAMPLE PROGRAMS........................................................................................................................3-6
3.7. REMOTE LOCK ..................................................................................................................................3-7
3.8. STANDARD PROTECTION FOR MULTIPLE SCANNERS .........................................................3-7
4. THEORY OF OPERATION................................................................................... 4-1
4.1. INTRODUCTION.................................................................................................................................4-1
4.2. HIGH ISOLATION LOW NOISE DESIGN ......................................................................................4-1
4.3. LOGIC CIRCUITS...............................................................................................................................4-1
4.4. PROTECTION FOR DEVICES CONNECTED TO THE SCANNER ...........................................4-2

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5. MAINTENANCE AND TROUBLE SHOOTING.................................................... 5-1
5.1. PERIODIC MAINTENANCE .............................................................................................................5-1
5.2. UNSTABLE READINGS .....................................................................................................................5-1
5.3. RELAY FAILURES..............................................................................................................................5-1
5.4. LOCATING THE RELAY CHANNELS............................................................................................5-2
6. CIRCUIT DIAGRAMS AND REPLACEMENT PARTS LIST................................ 6-1
6.1. INTRODUCTION.................................................................................................................................6-1
6.2. ORDERING INFORMATION ............................................................................................................6-1
6.3. CIRCUIT DIAGRAMS AND PARTS LISTS.....................................................................................6-2
7. DECLARATION OF CONFORMITY..................................................................... 7-1

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TABLE OF FIGURES
FIGURE 1-1 HIGH RESISTANCE SCANNER GUILDLINE MODEL 6564..................................................1-1
FIGURE 3-1 FRONT PANEL GUILDLINE MODEL 6564...............................................................................3-1
FIGURE 3-2 REAR PANEL GUILDLINE MODEL 6564..................................................................................3-2
FIGURE 4-1: FUNCTIONAL DIAGRAM OF SCANNER..................................................................................4-2

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v
LIST OF TABLES
TABLE 3-1: BUS ADDRESS...................................................................................................................................3-4

Section 1
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1-1
1. INTRODUCTION
1.1. DESCRIPTION
The Guildline Low Thermal Scanner, with extremely low leakage, is ideal for automating
precision high value measurements to ppm accuracy. This scanner has high isolation and
low noise making it suitable for a wide variety of uses. It can be used for high resistance
measurements into the Peta-Ohms as well as low current measurements into the fempto-
Amps.
Special care has been taken to minimize leakage and noise susceptibility. The switches
used are latching relays requiring only a few millisecond pulses to actuate. Several
systems are used to protect the devices connected to the scanner from being damaged by
operator error or scanner failure. It can be operated from the front panel or by commands
sent over the General Purpose Interface Bus.
The 6564 has been designed in a modular fashion in banks of 8 channels. It is possible to
have either 16 channels or 8 channels installed. A cover plate is installed on the front and
rear of the 8 channel models covering the channels 9 through 16. This allows for the 8
channel model to be factory upgraded to 16 at any time.
Figure 1-1 High Resistance Scanner Guildline Model 6564

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1-2
1.2. SPECIFICATIONS
NUMBER OF INPUTS
8 or 16 for Model 6564
ISOLATION **
700 Peta-Ohms Typical, 100 Peta-Ohms Minimum
SYSTEMATIC ERROR DUE CHANNEL VARIABILITY **
Leakage will vary by 3.3% of 100 Peta-Ohms typical, 5% of 100 Peta-Ohms
maximum.
ENVIRONMENTAL LIMITS
Operating: 10oC to 40oC up to 80% relative humidity
Storage: -20oC to 65oC up to 95% relative humidity
** Note: Specifications apply only if temperature is stable within 1oC, free of
drafts and the relative humidity is below 70%. Warm the scanner up for 2 hours
min.
SCANNER CONTROL
Local, using front panel push-buttons
Remote, via IEEE-488 bus (interface included)
RELAY CONTACT RATINGS
Life: greater than 10,000,000 cycles at low levels
Current: 2 amps maximum at 10 volts
Voltage switched: 100 volts maximum at 1 milliamp
Voltage non-switched*: 1000 volts max. (for terminal inputs)
*CAUTION - reduce voltage before actuating relays.
NOTE: when applied voltage is above 30 volts, the current source must limit the
current to less than 2 milliamps to meet IEC 1010-1/EN61010-1 safety
requirements.
SIZE
Length: 420 mm (16.5 in.)
Width: 451 mm (17.7 in.)
Height:133 mm (5.2 in.)
WEIGHT
16 channel scanner: 10 kg (23 lb.)
LINE POWER
100V, 115V-127V, 220V-230V, 240V all ±10%; 50-60 Hz

Section 1
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1-3
1.3. REAR PANEL CONNECTIONS
SCANNER INPUTS
Low noise High Voltage BNC for voltage source, Low noise Triax for input (low
current return).
OUTPUT LINES
Two low noise N-Type connectors, one each for source and input.
INTERFACE BUS
24 pin IEEE-488 connector, CINCH No. 57-20240
REFERENCE STANDARD PROTECTION
Screw terminals connected to open collector TTL logic circuit. Terminal goes
low (0 volts) when any relay is closed, and goes high (5 volts through 10k ohm)
when all relays are open. This line can be connected in parallel with other
scanners cascaded in a large system to protect standards from being shorted
together.
1.4. REFERENCE STANDARD PROTECTION SYSTEMS
Three systems are used to help protect standards from being damaged due to scanner
failure or operator error. These systems are described briefly below. See Theory of
Operation Section for complete description.
a. The relays are driven from a decoder so that only one output circuit can be
activated for any possible input combination.
b. Contacts on each relay are connected in series so that all input lines must be open
before power is available to close a relay.
c. Two push-buttons must be depressed at the same time to actuate any relay, which
requires two hands to operate.

Section 2
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2-1
2. INSTALLATION
2.1. INITIAL INSPECTION
This instrument was carefully inspected both mechanically and electrically before
shipment. It should be free of mars and scratches and in perfect electrical order upon
receipt.
Unpack the instrument and retain the shipping container until the instrument has been
inspected for damage in shipment. If in-shipment damage is observed, notify the carrier
and obtain authorization for repairs before returning the instrument to the factory.
2.2. POWER REQUIREMENTS
The instrument is shipped with a either three-wire line cord or external power pack. Both
configurations must be connected to a grounded 50 to 60 Hz ac power source. This
product will operate at between 100V and 240V all ±10%.
WARNING: BEFORE SWITCHING ON THIS INSTRUMENT, THE
PROTECTIVE TERMINAL OF THIS INSTRUMENT MUST BE
CONNECTED TO A PROTECTIVE EARTH CONTACT. THE POWER
LINE CORD SUPPLIED WILL PROVIDE THE PROTECTIVE
GROUNDING WHEN INSERTED INTO A SOCKET OUTLET
PROVIDED WITH AN EARTH CONTACT. THE PROTECTIVE
ACTION MUST NOT BE NEGATED BY THE USE OF AN
EXTENSION CORD OR ADAPTOR WITHOUT A PROTECTIVE
GROUNDING CONDUCTOR.
2.3. LOCATION
To insure optimum performance, the scanner should be installed in an area having
reasonably constant temperature, no strong electrostatic or magnetic fields, and a
minimum amount of vibration. The unit should not be located near heating or cooling
vents or in direct sunlight. Such locations can cause sudden temperature changes
resulting in generation of thermal errors in the measurements. A cloth can be placed over
the binding posts on the rear panel (and at the connections to your devices) to shield it
from drafts to further reduce thermal errors.

Section 3
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3-1
3. OPERATION
3.1. FRONT PANEL CONTROLS AND INDICATORS
Figure 3-1 Front Panel Guildline Model 6564
1. Line POWER on/off switch
2. LINE A push-button - when depressed will cause any relay on the A line to be cleared.
3. Numbered relay control push-buttons - when depressed at the same time that either the A
LINE or the B LINE push-button is depressed will cause the corresponding relay to close.
4. LINE A lights - indicates which LINE A relay is closed.
5. REMOTE light - is illuminated when the scanner is in bus control. The front panel push-
buttons are inoperative.
6. LOCAL Light - is illuminated when the scanner is in front panel (local) control.
7. Cover Plate (installed over unused channels 9 –16 for 8 channel option)
1
2
3
4
6
5
7

Section 3
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3-2
3.2. REAR PANEL CONNECTIONS
Figure 3-2 Rear Panel Guildline Model 6564
1. SCANNER INPUTS - Terminal inputs,
Connect BNC terminals to one side of units under test and Triax terminals to the opposite
side of the units under test. Numbers correspond to front panel relay numbers.
2. SOURCE OUTPUT - Connect to source input of teraohmmeter.
3. LOW CURRENT OUTPUTS - Connect to low current input of teraohmmeter.
4. GUARD - Connected to chassis at relay isothermal box.
5. PROTECT CIRCUIT - Connect to same terminals on other scanners. Provides protection
for standards in a multiple scanner system. See Section 3.9 for details.
6. INTERFACE BUS - IEEE-488 bus connector used to connect scanner to controller.
7. 5V DC POWER INPUT - from external power supply.
8. Cover Plate (installed over unused channels 9 –16 for 8 channel option)
6
1
3
2
4
8
7
5

Section 3
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3-3
3.3. FRONT PANEL OPERATION
The scanner must be in local mode (LOCAL light on) to operate from the front panel.
To connect one of the channel inputs to the output proceed as follows:
a. Press and hold down the CHANNEL push-button. This will cause any previously closed
relay on the CHANNEL to be cleared.
b. Press the numbered push-button corresponding to the input to be connected. This will
cause the relay to actuate connecting the input line to the CHANNEL output and also turn on
the appropriate light.
NOTE: The push-buttons can be depressed in either order and the end result will be the
same; that is, any previously closed relay will be opened and the desired relay will be closed.
The important thing is that two push-buttons must be pressed for any relay to close.
3.4. ADDRESS SELECTION
The IEEE-488 bus address of the scanner is selected by the “DIP” switches located on the
interface board under the top cover. The five switches labelled 1 through 5 are used to select
a unique address. The scanner normally leaves the factory with the switches set to a bus
address of 5. When two scanners are ordered, addresses are set to 5 and 6. Switch No. 6 is
used to lock the scanner in remote only. The following table lists the address codes and
corresponding switch settings:

Section 3
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3-4
ASCII Code Character
Address Switches
5 Bit
Decimal
Listen
Talk
A5
A4
A3
A2
A1
Code
SP
@
0
0
0
0
0
00
!
A
0
0
0
0
1
01
"
B
0
0
0
1
0
02
#
C
0
0
0
1
1
03
$
D
0
0
1
0
0
04
%
E
0
0
1
0
1
05
FACTORY
&
F
0
0
1
1
0
06
SETTING
`
G
0
0
1
1
1
07
(
H
0
1
0
0
0
08
)
I
0
1
0
0
1
09
*
J
0
1
0
1
0
10
+
K
0
1
0
1
1
11
`
L
0
1
1
0
0
12
M
0
1
1
0
1
13
.
N
0
1
1
1
0
14
/
O
0
1
1
1
1
15
0
P
1
0
0
0
0
16
1
Q
1
0
0
0
1
17
2
R
1
0
0
1
0
18
3
S
1
0
0
1
1
19
4
T
1
0
1
0
0
20
5
U
1
0
1
0
1
21
6
V
1
0
1
1
0
22
7
W
1
0
1
1
1
23
8
X
1
1
0
0
0
24
9
Y
1
1
0
0
1
25
:
Z
1
1
0
1
0
26
;
{
1
1
0
1
1
27
<
\
1
1
1
0
0
28
=
}
1
1
1
0
1
29
>
~
1
1
1
1
0
30
Table 3-1: Bus Address
6 5 4 3 2 1
Position 1
awayfromboard
RemoteLock
switch Address 24 shown
Interface Board
Position 0
towards board

Section 3
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3-5
3.5. OPERATION FROM INTERFACE BUS
The interface circuit is designed to accept coded data sent over the bus to actuate the relays.
To operate with the bus the scanner must be set to a usable address and must be connected to
the controller using a 24 pin IEEE-488 cable (not supplied).
The scanner was set at the factory for bus address 5, while all the examples that follow
assume 24 as the address. The address can be easily changed if necessary by means of a
“DIP” switch on the interface board located under the top cover. Refer to paragraph 3.4 for
the procedure to change the bus address.
To actuate a relay the bus interface must first receive the correct address, then a three
character ASCII codes designating the relay, and then a carriage return/line feed. For
example using an HTBasic computer, the statement:
OUTPUT 724;”A01”
Would cause any relay on the CHANNEL to be cleared, and then relay number 1 to be
closed. In this example
7 is the controller IO address,
24 is the scanner address and
A01 is the code for relay 1 on the CHANNEL
Note that each actuation must be a separately addressed statement. For example, the
following is not valid:
OUTPUT 724;”A00”,”A02” —NOT VALID—
Note also that a delay of at least 200 milliseconds must occur between any two actuations to
allow the relays to complete their operation.
Programming languages such as LabVIEW®that do not automatically add a carriage return/
line feed at the end of the command will require a CR/LF or simply a fourth alphanumeric
character to be added to the command when addressing the scanner. The following examples
use a space as the fourth character or the CR/LF.
IBWRT "A01 “

Section 3
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3-6
3.6. SAMPLE PROGRAMS
The following program will exercise the scanner relays 1 through 16 and leave the line clear.
This program is for HTBasic computers with the scanner address set to 724.
10 ! SCANNER TEST
20 DIM Relay$[16]
30 Relay$=”01020304050607080910111213141516”
40 FOR I = 1 TO 16
50 OUTPUT 724;”A”&Relay$[2*I-1,2*I] ! CLOSES A RELAY
60 WAIT .2
70 NEXT I
80 OUTPUT 724;”A00” ! CLEARS CHANNEL
90 END
Note: A Wait of at least 200 milliseconds is required between relay actuations to allow time for
the relay circuits to actuate.
The second program example has exactly the same result as the first program listed above but
uses string output statements. The formatted output statement is used to assure the first character
that the scanner sees (after the address) is the line code and the next two characters are the relay
code.
10 ! SCANNER TEST
30 FOR I = 1 TO 16
40 OUTPUT Code$ USING “A,ZZ”;”A”,I ! SETS CODE
50 OUTPUT 724; Code$ ! CLOSES A RELAY
60 WAIT .2
100 NEXT I
110 PRINT “A00” ! CLEARS CHANNEL
140 END

Section 3
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3-7
3.7. REMOTE LOCK
The push-buttons can be locked out when it is desired to prevent tampering from the front
panel. Position No. 6 of the “DIP” switch located on the Interface printed circuit board is
used to lock the scanner in remote only. If the switch is the “O” position (towards the PC
board) the REMOTE light will be on and the front panel push-buttons will not operate. The
scanner can only be actuated by the bus in the usual manner. The scanner address must still
be used in the output command to actuate the relays.
3.8. STANDARD PROTECTION FOR MULTIPLE SCANNERS
The protection feature can be extended to multiple scanners in a large system by means of the
rear panel PROTECT terminal. The protection circuit prevents more than one relay on either
scanner CHANNEL from being closed at the same time that prevents standards from being
shorted together. Each relay has a contact that closes when the relay is in the open position.
These contacts must all be closed (relays open) for the logic circuit to allow a close pulse to
be sent out. This protection can be extended to more than one scanner in a large system by
connecting the PROTECT terminals together. The PROTECT terminal is connected to an
open collector TTL gate on the control board. When all relays are open the terminal will be
high (5 volts through 10k ohm), and when any relay is closed the terminal will be low (near 0
volts). Connecting either terminal to COM will prevent any relay on that line from being
activated.
To extend this protection feature when two or more scanners are used in a system, connect all
PROTECT terminals together, and all PROTECT COM terminals together.

Section 4
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4-1
4. THEORY OF OPERATION
4.1. INTRODUCTION
Guildline High Resistance Scanners with extremely low leakage are ideal for automating
precision high resistance and low current measurements to ppm accuracy. This versatile
scanner a set of shielded high isolation output lines that make it suitable for these
applications. It can be used for automation of High Resistance transfers, measurements, and
comparing current sources.
4.2. HIGH ISOLATION LOW NOISE DESIGN
Special care has been taken to minimize current leakage and susceptibility to noise. The
switches used are latching relays requiring only a short pulse to actuate, and thus no self-
heating occurs.
Relays are hermetically sealed and make connection by for the high and low side of any
input on separate isolated PCB to ensure high isolation and low leakage.
Switching assemblies with eight relays to a PC board are housed in a heavy machined
aluminum box. This isothermal enclosure helps to maintain a uniform temperature at each
of the relay contacts and provide an excellent EMI shield for low current measurement.
The printed circuit edge connectors carry only the relay coil and panel light circuits. All
the channel input lines are soldered to the relay boards directly to prevent the thermal and
noise voltages caused by connectors.
4.3. LOGIC CIRCUITS
The scanner is designed to allow easy operation from both the IEEE-488 Bus and the front
panel. The information from the bus is in binary form sent serially, one ASCII character at
a time. This serial format is changed to a parallel format by means of a decoder ROM on
the interface board as can be seen in Figure 4.1.
To allow the system to operate from the front panel, the push-button data is converted to a
form identical to binary data from the bus interface circuit. A selector at this point switches
between bus and push-button operation. A 6-to-64 line decoder after the selector converts
the 6-bit parallel data to a single line output which actuates one of the relay coil drivers.

Section 4
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4-2
4.4. PROTECTION FOR DEVICES CONNECTED TO THE SCANNER
Some devices such as standard cells can be damaged if two relays on the same output line
are closed at the same time. The Guildline Instrument Limited scanners have three
methods to protected devices connected to the scanner inputs.
Two of the three protection schemes can be seen in Figure 4.1. The first one is in the logic
itself. The data at the selector is in six bit binary. Thus only one of the 64 relays can be
activated for any possible combination of the six input lines. If a failure should occur in
the bus interface, encoder or selector circuits, or if an incorrect message is sent over the
bus, no devices will be damaged because only one relay can be closed.
32 to 5
Line
Encoder
A/ B
Selector
BUS
Inter-
Face
BUS /
Push-
Button
Selector
6 TO 64
Line
Decoder
and
Relay
Drivers
Logic
Control
Circuit
ALine
B Line
GPIB
Inputs
Remote
+5 or
+15V
AClose
Gate To Relay
Clear Ckt
A
B
To Rear
Panel
32 B RelayContacts
Series Protect Lines
B Close
Gate
32 A RelayContacts
16 or 32 Front Panel
RelaySelector
Pushbuttons
(16 or 32) A-Line
RelayCoils
(16 or 32) B-Line
RelayCoils
Figure 4-1: Functional Diagram of Scanner
Channel
Selector