IET Labs PRS-200 Series User manual

♦PRECISION INSTRUMENTS FOR TEST AND MEASUREMENT ♦
TEL: [phone] • [phone] • FAX: [phone]
www.ietlabs.com
IET LABS, INC.
PRS-200 SERIES
High Precision
Manual or SCPI Programmable
Decade Resistance Substituters
(IEEE-488.2, RS232 or Ethernet)
Operation Manual
Copyright  2015 IET Labs, Inc.
PRS200 IEEE.2 im/May 2015

♦PRECISION INSTRUMENTS FOR TEST AND MEASUREMENT ♦
TEL: [phone] • [phone] • FAX: [phone]
www.ietlabs.com
IET LABS, INC.

WARRANTY
We warrant that this product is free from defects in material and workmanship and, when properly used,
will perform in accordance with applicable IET speci cations. If within one year after original shipment,
it is found not to meet this standard, it will be repaired or, at the option of IET, replaced at no charge when
returned to IET. Changes in this product not approved by IET or application of voltages or currents greater
than those allowed by the speci cations shall void this warranty. IET shall not be liable for any indirect,
special, or consequential damages, even if notice has been given to the possibility of such damages.
THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED,
INCLUDING BUT NOT LIMITED TO, ANY IMPLIED WARRANTY OF MERCHANTABILITY OR
FITNESS FOR ANY PARTICULAR PURPOSE.
i

WARNING
OBSERVE ALL SAFETY RULES
WHEN WORKING WITH HIGH VOLTAGES OR LINE VOLTAGES.
Dangerous voltages may be present inside this instrument. Do not open the case
Refer servicing to quali ed personnel
HIGH VOLTAGES MAY BE PRESENT AT THE TERMINALS OF THIS INSTRUMENT
WHENEVER HAZARDOUS VOLTAGES (> 45 V) ARE USED, TAKE ALL MEASURES TO
AVOID ACCIDENTAL CONTACT WITH ANY LIVE COMPONENTS.
USE MAXIMUM INSULATION AND MINIMIZE THE USE OF BARE
CONDUCTORS WHEN USING THIS INSTRUMENT.
Use extreme caution when working with bare conductors or bus bars.
WHEN WORKING WITH HIGH VOLTAGES, POST WARNING SIGNS AND
KEEP UNREQUIRED PERSONNEL SAFELY AWAY.
CAUTION
DO NOT APPLY ANY VOLTAGES OR CURRENTS TO THE TERMINALS OF THIS
INSTRUMENT IN EXCESS OF THE MAXIMUM LIMITS INDICATED ON
THE FRONT PANEL OR THE OPERATING GUIDE LABEL.
ii

CONTENTS
WARRANTY................................................................................................ i
WARNING .................................................................................................. ii
CAUTION ................................................................................................... ii
Chapter 1: INTRODUCTION ..................................................................... 1
Chapter 2: SPECIFICATIONS ................................................................... 3
2.1 Model Conguration and specications ............................................................3
2.2 General specications ........................................................................................4
Chapter 3: OPERATION............................................................................ 7
3.1 Initial inspection and setup ................................................................................7
3.2 Connection .........................................................................................................7
3.2.1 General Considerations ............................................................................7
3.2.2 Electrical Considerations .........................................................................7
3.2.3 Four-Wire Kelvin Lead Connections .......................................................7
3.2.4 Thermal emf Considerations....................................................................7
3.3 Dial Setting ........................................................................................................8
3.4 Environmental Conditions .................................................................................8
3.5 Local Operation .................................................................................................8
3.6 Remote Operation ..............................................................................................8
Chapter 4: ETHERNET OPTION............................................................. 10
4.1 Ethernet Programming .....................................................................................10
4.2 Network Setup ............................................................................................................. 10
4.3 Ethernet Test Keyboard ........................................................................... ....................10
4.4 Network Conguration ................................................................................................ 11
4.5 Web Browser Conguration ........................................................................................ 11
4.6 VXI Conguration Utility ........................................................................................... 13
4.7 Resetting Default Network Settings ............................................................................ 15
4.8 PRS Programming ....................................................................................................... 15
Chapter 5: IEEE INTERFACE OPTION................................................... 16
5.1 Introduction .......................................................................................... 16
5.2 Capabilities ........................................................................................... 16
5.3 Address Switch and Communications Settings.......................................... 16
5.4 IEEE Option Operation .......................................................................... 17
5.5 GPIB Test Keyboard ........................................................................................17
iii

Chapter 6: SERIAL INTERFACE OPTION.............................................. 18
6.1 Introduction .......................................................................................... 18
6.2 Capabilities ........................................................................................... 18
6.3 Signal Interface and Communications Settings ......................................... 18
6.4 Serial Option Operation.......................................................................... 18
6.5 Serial Test Keyboard ........................................................................................19
Chapter 7: PROGRAMMING................................................................... 20
7.1 Introduction .......................................................................................... 20
7.2 Command String Structure ..................................................................... 20
7.3 Advanced Programming Software Driver ................................................. 21
Chapter 8: MAINTENANCE .................................................................... 24
8.1 Verication of Performance .................................................................... 24
8.2 Calibration Interval................................................................................ 24
APPENDIX A: SCPI COMMAND REFERENCE...................................... 25
APPENDIX B: IEEE.2 COMMON COMMANDS ...................................... 27
iv

INTRODUCTION
PRS-200 Series
1
Chapter 1
INTRODUCTION
The PRS Series (Figure 1.1) is a broad
line of high precision manual and program-
mable decade substituters. They provide direct
resistance substitution as well as RTD (Resis-
tance Temperature Detector) simulation, in a
wide selection of ranges, tolerances and rat-
ings.
The PRS substituter is a precision resis-
tance source with excellent characteristics of
stability, temperature coefcient, and power
coefcient. High dynamic ranges are avail-
able, starting as low as 1 mΩ, and extending
to as many as 10 decades. These features
combined with a low virtually constant “zero
resistance” make for very versatile instruments.
The PRS Series features two optional
special settings. An “open circuit” and a “short
circuit”. These modes are useful for obtaining
reproducible transitions between settings, i.e.
break-before-make or to short between set-
tings. The “short circuit” setting also provides
a reduced zero resistance.
Operation is both local using convenient
direct-reading front panel thumbwheel switch-
es, and remote with optional Ethernet, RS-232,
or IEEE-488 interfaces. Both can provide an
optional extra “10” position for each decade.
The PRS Series employs very low resis-
tance, low thermal emf relays with gold-clad
silver-alloy contacts. A special design keeps
contact resistance to a minimum. The gold
plating keeps the silver contacts from becom-
ing tarnished when unused, or when only low
currents are passed through them. This is most
often the case when only minute test currents
are drawn by digital multimeters and other test
instruments. Contact resistance remains low
and repeatable.
High-quality gold-plated tellurium-copper
ve-way binding posts serve to minimize the
thermal emf effects, which would produce er-
rors in dc resistance measurements. All other
conductors within the instrument, as well as the
solder employed contain no metals or junctions
that could contribute to thermal emf problems.
With a resolution as low as 1 mΩand
a maximum available resistance of over 100
MΩ, the PRS-202 Series may be used for
exacting precision measurement applications
requiring high accuracy, good stability, and low
zero resistance. They are suited for automatic
and manual calibration and testing, simulation
of RTD’S, programmable loads, and many
other laboratory and industrial applications.
The PRS Series may be rack mounted
to serve as components in measurement and
control systems.
Figure 1.1: High Precision Manual or Programmable
Decade Resistance Substituter

INTRODUCTION
PRS-200 Series
2
This page is intentionally left blank.

OPERATION
PRS-200 Series
5
FIGURE 2.1 Typical OPERATING GUIDE Afxed to Unit
(Please see label afxed to your unit)
PRS SERIES OPERATING GUIDE
WARNING
CONSULT INSTRUCTION MANUAL FOR PROPER INSTRUMENT OPERATION
Resistance Type: Metal film.
Range: 0 to 9,999,999 Ω, in 1 Ωsteps.
Accuracy: ±(0.1% + 30 mΩ), after subtraction of zero setting resistance; traceable to NIST.
Zero Resistance: <450 mΩ, <410 mΩ, typical; <560 mΩ if OC (Open Circuit) option is pres-
ent; <20 mΩ, with SC (Short Circuit) option activated.
Maximum Load: 0.5 A, or 200 V (dc + peak ac), or 1 W/step, whichever applies rst.
Interface: IEEE-488.2-1987,SCPI 1994.0; front panel switch selects REMOTE or LOCAL
operation; “*IDN” for S/N, Model & REV; “CAL:DATe?” for last calibration date.
Ground: GND terminal on front panel is connected to both chassis and earth ground.
Operation: Unit should be allowed to stabilize for one hour. For maximum stability, allow unit
to warm-up over two hours and keep free from mechanical disturbances.
Observe all safety rules when working with high voltages or line voltages. Connect the shield to earth
ground in order to maintain the case at a safe voltage. Whenever hazardous voltages (>45 V) are used,
take all measures to avoid accidental contact with any live components: a) Use maximum insulation and
minimize the use of bare conductors. b) Remove power when adjusting switches. c) Post warning signs
and keep personnel safely away.
CAGE CODE: 62015 www.ietlabs.com
IET LABS, INC. • Long Island, NY • [e-mail] • [phone] • [phone]
PRSBLBL/p27/PRS201-1W-IEEE.2/05-15
SN: G2-XXXXXXX
FUSE: 0.25 A
MODEL: PRS-201-1W-IEEE.2
POWER: 105-125 V, 50-60 Hz

PRS-200 Series
OPERATION
6
Chapter 3
OPERATION
3.1 Initial inspection and setup
This instrument was tested and carefully
inspected before shipment. It should be in
proper electrical and mechanical order upon
receipt.
An OPERATING GUIDE is attached
to the case of the instrument to provide ready
reference to specications.
Mount the unit in a standard 19” rack if
the rack mount option is specied.
3.2 Connection
3.2.1 General Considerations
The PRS Series Decade unit is built in
3-terminal or 5-terminal versions. The binding
posts are standard laboratory type and readily
accept banana plugs, telephone tips, spade lugs,
alligator clips, and bare wire. Binding posts
are located on the front panel of the instrument
unless specically ordered with a Rear Output
option.
The 3-terminal version posts are labeled
HI, LO, and GND. The HI and LO terminals
are connected to the ends of the internal imped-
ance being set.
5-terminal models provide four Kelvin
terminals consisting of a CURRENT and a
SENSE pair, each labeled HI and LO. These
minimize contact resistance.
The GND terminal on all models is con-
nected to the case and to earth and chassis
grounds. This may be used as a shield terminal.
3.2.2 Electrical Considerations
The performance of the PRS is directly
affected by the quality of the connection to the
system under test. This is particularly true with
the precision series models having higher-accu-
racy and/or lower-impedance decades.
For optimum performance, contact resis-
tance should be kept to a minimum by using
the most substantial mating connection possi-
ble, and by assuring that the connection is well
secured to the binding posts.
3.2.3 Four-Wire Kelvin Lead Connec-
tions
4-wire Kelvin leads minimize the effects
of contact resistance and approach ideal per-
formance. The CURRENT and SENSE HI/
LO terminal pairs may be shorted together to
provide a 2-terminal connection in instances
where high accuracy is not a concern.
3.2.4 Thermal emf Considerations
The PRS Series uses high-quality, low-
emf components. Thermal emf is primarily
attributable to the temperature difference
between the leads of the relay and the contacts
when temperature is applied to the coil. This
emf is of the order of 5 µV per relay, but is not
usually additive. The typical worst case is <15
µV.

OPERATION
PRS-200 Series
7
If the effect of tens of microvolts is
signicant to your application, connect to the
instrument with low-thermal-emf materials
only. Copper wire and copper alloys are rec-
ommended; brass and steel should be avoided.
Tinned copper and solder are acceptable.
This emf will not be reected if an ac
measurement instrument is employed, and
can be eliminated by using a meter with “True
Ohm” capability. In other cases, the emf may
represent a very small component of a dc resis-
tance measurement.
3.3 Dial Setting
Each decade is manually controlled via a
front panel thumbwheel that provides positions
for “0” through “9”. The total impedance is set/
read directly from the dial setting. The deci-
mal point, if any, is marked on the thumbwheel
switches, and the steps are clearly marked on
the panel. Short Circuit / Open Circuit mode
control is only available using a Remote con-
trol option.
3.4 Environmental Conditions
The PRS is built, calibrated and intended
for use in a laboratory environment with a
nominal ambient temperature near 23oC. The
accuracy of the unit may be affected when
operated in non-laboratory environments. Al-
ways allow the instrument to stabilize at room
temperature after unpacking or relocating the
instrument. Humidity should be maintained at
laboratory conditions.
3.5 Local Operation
Operation of the PRS substituter is
straightforward and graphically represented on
the front panel.
1. Turn on the POWER switch. The
POWER indicator lamp, if present,
should come on. If a REMOTE op-
tion is present, the READY and LO-
CAL indicators should illuminate.
2. Set the REMOTE/LOCAL switch to
LOCAL.
3. Connect any desired instrumentation
to the front panel binding posts. The
GND terminal may be connected to
the ground of external equipment.
The GND terminal is connected to
the case and to both chassis and earth
grounds.
4. Make 4-terminal or 2-terminal con-
nections as described previously. A
shielded set of cables is recommended
whenever ac operation or high resis-
tance are involved.
5. Set the thumbwheel switches to
provide the desired impedance in the
units indicated on the front panel.
3.6 Remote Operation
The PRS includes a REMOTE/LOCAL
switch on the front panel. The REMOTE
position is a remote enable. When in LOCAL
mode, the PRS supplies the impedance value
selected using the front panel thumbwheel
switches.
When the switch is in the REMOTE
position, the PRS will supply the congured
remote impedance value only if that option
asserts remote control. If the option does not
assert control, the front panel thumbwheel im-

PRS-200 Series
OPERATION
8
pedance value is supplied. The REMOTE and
LOCAL LEDs always indicate which inter-
face is controlling the impedance value.
Setting the front panel REMOTE/LO-
CAL switch to LOCAL overrides the RE-
MOTE option settings and always sets the
supplied impedance to the value selected using
the front panel thumbwheels, regardless of the
REMOTE option’s assertion of control.
The REMOTE BCD option sets imped-
ance values and asserts control using TTL
logic. The impedance values are BCD encoded
as shown in table 4.2.
For IEEE and RS232 units, the LOCAL
indicator remains on until communication
with the unit is initialized. The mode changes
to REMOTE after controller commands are
received.

PRS-200 Series
ETHERNET INTERFACE OPTION 9
Chapter 4
ETHERNET INTERFACE OPTION
4.1 Ethernet Programming
PRS units, with Ethernet interface option,
come with Ethernet remote programming capa-
bility accessed through the RJ45 LAN connec-
tor. The connector is a RJ45 industry-standard
connector found on the rear panel. The PRS’s
Ethernet connection is based upon the ICS
8003 LAN to Parallel Interface Card. More
information can be found at www.icselect.com
on the 8003 Ethernet Card.
4.1.1 Ethernet Protocols
The PRS supports Raw Socket and the
VXI-11 protocol which makes it easy to con-
trol from a PC or over the company network.
Raw socket lets you telnet to it and is best
used with direct PC to instrument applications.
VXI-11 operates over Sun RPC and is a more
secure protocol that mimics GPIB control of an
instrument and provides secure communication
over a company network or over the Internet.
4.1.2 Raw Socket Operation
The PRS is always ready for a telnet con-
nection. When connected, the PRS outputs
its IDN message to confirm the connection.
All raw socket messages are terminated
with a linefeed. Carriage returns and ignored. A
backspace character causes the prior character to
be deleted. Communication timeout is two min-
utes and it is recommended that the client issue a
Space-BS sequence on an occasional basis, less
than the timeout, to reset the timeout counter.
4.1.3 VXI-11 Background
VXI-11 is a communication standard devel-
oped in conjunction with the VISA Specication.
The specication denes a VXI-11.3 interface
like the PRS as an instrument which can be
controlled in Windows systems by programs
that make VISA or SICL library calls and in
UNIX/LINUX or similar operating system with
RPC calls. The VXI-11 specication provides
an RPCL (Remote Procedure Call Library) that
can be used by virtually any operating system to
control the PRS. Microsoft’s RPC is not ONC
compliant and cannot be used with a VXI-11.3
device like the PRS. An VXI-11.3 interface
like the PRS will operate in an LXl system and
it supports LXI’s ‘VXI Discovery Method’.
4.2 Network Setup
The PRS includes an internal WebServer with
HTML web pages that can be accessed by a web
browser from any computer. The web pages let
the user quickly change the PRS network settings.
The default IP address is 192.168.1.253 static.
4.3 Ethernet Test Keyboard
To assist the user in setup and com-
munication the VXI-11kybd program
can be used which includes defined RPC
calls to change the PRS network settings.
VXI-11 Keyboard Control Program provides
interactive control of VXI-11 instruments from
the computer keyboard without having to write a
program. The VXI-11 Keyboard program is the
ideal utility program for conguring and testing the
PRS or any VXI-11 compatible instrument. Use
the VXI-11kybd program to exercise the interface

PRS-200 Series
ETHERNET INTERFACE OPTION10
or to try out commands before using them in a
program. The VXI-11kybd program can be found
on the PRS product page at www.ietlabs.com
Versatile Programming
The PRS can be easily controlled by several
programming techniques and languages because
it is a VXI-11.3 instrument. If you program
with LabVIEW, National Instruments’ VISA
supports VXI-11.3 instruments like the PRS. NI’s
Measurement and Automation Explorer treats
the PRS as a TCP/IP compliant device. Agilent’s
VISA library supports VXI-11.3 instruments and
the Agilent Connection Manager sees the PRS as
a TCP/IP instrument.
If you are a Visual Basic, VB.Net or C/C++
programmer, you can write your program to
call Agilent’s or National Instruments’ VISA
or Agilent’s SICL library in the Windows
environment.
If you use LINUX or any other avor of UNIX
like SunOS, IBM-AIX, HP-UX, or Apple’s OS X,
you can communicate with the PRS through RPC
over TCP/IP. RPC (or Remote Procedure Calls)
provides an invisible communication medium for
the developer. The VXI-11 specication provides
an RPCL (Remote Procedure Call Library) that
can be used by virtually any operating system
to control the PRS.
If you program with Java then you can write a
PRS control program that can be easily moved
to many different operating systems.
The Java jGpibEnet project on SourceForge was
developed using an ICS 8065 Controller similar
to the PRS Controller.
4.4 Network Configuration
This paragraph congures the 8003 card in the
PRS for operation on your network. The board’s
digital interface is congured later by sending
commands as outlined in Appendix A.
When shipped, the boards are congured with
default settings outlined in Table 4-1 Default
Settings.
Command Function Factory Setting
IP Mode Static or DHCP
Mode
Static
IP Address 0.0.0.0 to
255.255.255.255.0
192.168.1.254
Net Mask 0.0.0.0 to
255.255.255.255.0
255.255.255.0
COMM Timeout Sets socket timeout 120 sec.
Auto Disconnect Aborts socket if link
count goes to 0
Off
Table 4-1 Default Settings
Review the Table with your network administrator
and decide on which settings, if any, that need
to be changed. Table 4-1 provides detailed
information about each network setting to help
you with your decisions. The minimum change
is to set a static IP address so your PC can
communicate with the board.
The network conguration can be changed and
the board’s MAC Address can be read with a web
browser, by running ICS’s VXI-11 Con guration
Utility on a WIN32 or WIN98 PC. ,
4.5 Web Browser Configuration
Method
This method uses a standard browser such as
Firefox, Internet Explorer or Safari to view and
change the current network settings.
1. Temporarily disconnect the computer from
the company network. Connect the PRS and
computer running the browser using a standard
Ethernet Cables to a hub or switch. Temporarily
disconnect the local network connection to avoid
network conicts until the board is congured.

PRS-200 Series
ETHERNET INTERFACE OPTION 11
Figure 4-1 8003 Connected to the local hub
An alternate connection is to use an Ethernet
Crossover Cable to connect the computer directly
to the PRS for initial conguration. This will
eliminate any potential network conicts while
conguring the PRS.
Figure 4-2 8003 Connected to the local hub
2. Apply power to the PRS. Set the Remote local
switch to Remote.
3. Check your computer’s network settings to
be sure its IP address is in the 192.168.1.xxx
range so it can communicate with the PRS
Ethernet board’s default IP address. If it is not,
it must be set before proceeding. Use the values
shown below. For Windows PCs, right-click on
My Network Places and click on Properties.
Right-click on Local Area Connection and click
Properties. Highlight Internet Protocol (TCP/IP)
and click Properties. If your PC’s IP address is in
a different range, record the current settings and
temporarily set the following network values:
Check ‘Use the following IP Address’
IP Address 192.168.1.254
Subnet mask 255.255.255.0
4. Open the browser and enter the default IP
address of 192.168.1.254 for new units (or your
last set address for older units) in the browser
address window.
5. A Welcome Page similar to the one shown
Figure 4-3 should appear in your browser.
6. If you want to change any of the settings,
press the ‘Update Configuration’ button. A
Conguration Page similar to the one shown in
Figure 4-4 should appear in your browser.
Figure 4-3 8003 Welcome Page

PRS-200 Series
ETHERNET INTERFACE OPTION12
Figure 4-4 8003 Conguration Page
7. Enter the new settings as desired. If you select
DHCP for the TCP/IP Mode, the page blanks out
the IP, Net and Gateway addresses as they will
be supplied by your DHCP server. Check the
entered values carefully as the unit’s webserver
does minimal error checking. Press the ‘Update
Flash’ button when done. A Conrmation Page
similar to the one shown in Figure 4-5 will appear
in your browser.
Figure 4-5 8003 Conrmation Page
8. Your new settings have been saved in the
board’s  ash memory. You have to reboot the unit
or power cycle it for the changes to take affect.
Press the ‘Reboot’ button to reboot the unit now
or the ‘Return to the Conguration Page’ button
to revisit the new settings.
4.6 VXI-11 Configuration Utility
Method
The VXI-11 Configuration Utility program
is called ‘VXI11_cong.exe’ and runs in any
WIN32 PC with Windows 98, Me, 2K, XP,
Vista, 7 and Server 2003 operating systems. The
VXI11_cong.exe program can be found on the
PRS product page at www.ietlabs.com.
The VXI11_cong program can be run from the
CD or can be installed onto your hard disk and
run from the installation directory.
VXI11_cong.exe is a Visual Basic program and
requires that either Microsoft’s Visual Studio 6
or VBruntime6 be installed on your PC to run.
1. Connect the board directly to the WIN32 PC
that will be running the Conguration Utility.
Disconnect the PC from the company network
and use the supplied Ethernet Crossover Cable to
connect the PC to the board as shown in Figure
4-6. This will eliminate any potential network
conicts while conguring the board.
Figure 4-6 8003 Connected to PC with a
Crossover Cable
Alternately, use a standard Ethernet patch cable

PRS-200 Series
ETHERNET INTERFACE OPTION 13
to connect the 8003 to the same hub or switch
that the PC running the Conguration Utility is
connected to as shown in Figure 4-7. Temporarily
disconnect the local network connection to avoid
network conicts until the board is congured.
Figure 4-7 8013 Connected to the local hub
2. Apply power to the board
3. Check your PC’s network settings to be sure
its IP address is in the 192.168.1.xxx range so
it can communicate with the board’s default IP
address. To check, right-click on My Network
Places and click on Properties. Right-click on
Local Area Connection and click Properties.
Highlight Internet Protocol (TCP/IP) and click
Properties. If your PC’s IP address is in a different
range, record the current settings and temporarily
set the following network values:
Check ‘Use the following IP Address’
IP Address 192.168.1.254
Subnet mask 255.255.255.0
4. Run the VXI11_config program. The
Conguration Utility opens a window as shown
in Figure 4-8. Initially only the Find Server, Help
and Exit buttons are enabled on the program
window. The other buttons will be enabled as
you advance through the program.
5. Click on the Find Server button. The program
scans for all VXI-11 Services connected to the
local LAN or to your PC. (The 8003 is an RPC
server which provide a VXI-11 Service) The
results are displayed in the Results box.
6. When the servers(s) have been found, use the
pulldown arrow in the Found Servers box to view
the Found Server addresses. The board’s
default address is 192.168.1.254. Highlight the
board’s IP address and click the Create Link
button. If the server is not found, you can enter
the default IP address (192.168.1.254) in the
Found Servers box. Click the Create Link button.
Figure 4-8 VXI-11 Conguration Utility
(Showing all configuration choices with no
changes)
7. When the link has been created, device model
number(s) will appear in the ‘Select Device to
be Congured’ box. Highlight the desired model
number and click the Congure button to start the
conguration process.
8. The Conguration Choices box displays only
one line with the rst parameter to be changed
and its current setting. If you like the current
setting, click Enter to advance to the next

PRS-200 Series
ETHERNET INTERFACE OPTION14
parameter. If you want to change the setting,
type a new value in the New Value box and click
Enter. The program will send your setting to the
board and read back the new setting. Repeat as
needed to make another change or click Enter
again to advance to the next parameter.
9. Repeat step 8 for each conguration parameter.
Figure 4-8 shows the VXI-11 Configuration
Utility after all parameters have been entered
for a Model 8003. Click the Redo From Start
button if you need to start over or if you want to
change any of the prior settings
10. When done, the Save Conguration button
is enabled if you changed any settings. Click the
Save Conguration button to save the values
in the board’s ash memory. If you did not make
any changes you can just exit the program.
11. The board has to be power cycled or rebooted
before the conguration changes take affect.
Click the Reboot button to reboot the board and
use the new settings.
12. Press the Exit button to quit the VXI11_con
g program.
13. If the IP address was changed to an address
outside the 192.168.1.xxx range in step 3, your
PC’s network settings will have to be changed to
communicate with the board. Exit the VXI11_
cong program and restore the PC’s network
settings.
4.7 Resetting Default Network
Settings
The board can be reset to the default network
settings listed in Table 4-2 at any time by holding
the LAN Reset Button in for 5 seconds while
applying power to the board. To accomplish this
the top cover of the PRS must be removed to gain
access to the 8003 Ethernet Board. The Digital
I/O conguration values are not affected by the
LAN Reset operation.
Command Function Factory Setting
IP Mode Static or DHCP
Mode
Static
IP Address 0.0.0.0 to
255.255.255.255.0
192.168.0.2
Net Mask 0.0.0.0 to
255.255.255.255.0
255.255.255.0
COMM Timeout Sets socket timeout 120 sec.
Auto Disconnect Aborts socket if link
count goes to 0
Off
Table 4-2 Default Settings
4.8 PRS Programming
A PRS SCPI command reference is in-
cluded in Appendix A. This gives a complete
set of commands.
An example of commands to be sent to
place the PRS in remote, this must be done
rst otherwise the will be no remote control of
output impedance, and then congure the unit
for a specic impedance value.
Where the command string is constructed
as described in Chapter 7.
A command string might be, for example:
CONFigure:REMote 1
SOURce:DATA 0000564120

PRS-200 Series
IEEE INTERFACE OPTION 15
Chapter 5
IEEE INTERFACE OPTION
5.1 Introduction
The IEEE interface option makes the
PRS-200 a IEEE-488.2-1987 and SCPI 1994.0
compatible instrument.
The IEEE STD 488.2 covers the electrical
and mechanical bus specications, and state
diagrams for each GPIB bus function. It also
establishes data formats, common commands
for each 488.2 device and controller protocols.
The standard is available on-line at http://www.
ieee.org.
The SCPI standard provides a tree like
series of standard commands for program-
mable instruments so that similar instruments
by different manufacturers can be controlled
by the same program. SCPI information and a
command reference are located in Appendix A.
Other tutorials are available on-line; con-
sult IET for additional information. A software
GPIB “keyboard” may be requested from IET
to perform elementary commands for training
and testing. See Section 5.5.
5.2 Capabilities
The IEEE option provides remote control
over all functions except POWER.
5.3 Address Switch and
Communications Settings
Each GPIB bus device is identied by a
ve-bit binary address. There are 32 possible
primary addresses 0 through 31; addresses
0 and 31 are reserved . The PRS BUS AD-
DRESS switch shown in Figure 5-1 establish-
es the GPIB address of the unit. Bus address
settings are read at power up. Refer to table
5.1.
The T-L-S positions on the BUS AD-
DRESS switch are not used and should remain
in the “OFF” position.
Table 5.1 IEEE Bus Address Settings
Figure 5-1: Bus Address Switch

PRS-200 Series
IEEE INTERFACE OPTION
16
5.4 IEEE Option Operation
The IEEE controller asserts the remote
mode upon receipt of a valid command. The
REMOTE LED will light and impedance
settings will be controlled through the IEEE
interface if the REMOTE/LOCAL switch
is in the REMOTE position. Remote control
may be dropped by issuing an IEEE GTL com-
mand. Dropping remote sets the PRS output to
the value set on the front thumbwheel switches.
See Chapter 3 for information about RE-
MOTE/LOCAL functionality.
5.5 GPIB Test Keyboard
To aid the user in operating the PRS, a
GPIB “Keyboard” Controller program - the
easiest way to control GPIB devices without
writing a program - is available from IET. This
GPIB Keyboard program automatically nds
your device at start-up and it lets you enter just
the data that you want to send to the device.
This program works with ICS, Measurement
Computing and National Instruments control-
lers.
To implement, request a download of
ICS_GPIBkybd_Install.zip from IET Labs
Tech Support.
Unzip the le and follow instructions to
install.
Open the application. You may use the
Find Listeners button to conrm that the PRS
unit is recognized. Other instruments may also
be recognized at this time.
Enter and set the Address to the PRS
address. Use the window to send a command
string to the PRS,
where the command string is constructed
as described in Chapter 7. A command string
might be, for example:
SOURce:DATA resistance
string