I-Tech IT8300 Series Operating instructions

Energy-regenerative DC
Electronic Load
Series IT8300 Programming Guide
Model: IT8311/IT8312/IT8321/IT8322/IT8331/IT8332/
IT8341/IT8342/IT8351/IT8352/IT8361/IT8362/IT8371
/IT8372/IT8381/IT8382/IT8391/IT8392
Revision: V1.0

IT8300 Programming Guide
Statement
© Itech Electronic, Co., Ltd. 2017 No
part of this manual may be reproduced
in any form or by any means (including
electronic storage and retrieval or
translation into a foreign language)
without prior permission and written
consent from Itech Electronic, Co., Ltd.
as governed by international copyright
laws.
Manual Part Number
IT8300-402227
Revision
1st Edition: APR 17, 2017
Itech Electronic, Co., Ltd.
Trademarks
Pentium is a registered trademark of
Intel Corporation in the United States.
Microsoft, Visual Studio, Windows and
MS Windows are trademarks of
Microsoft Corporation in the United
States and/or other countries/regions.
Warranty
Materials in the document are provided
talis qualis and may be changed in
future revisions without prior notice. In
addition, within the maximum allowable
extent of laws, ITECH is not committed
to any explicit or implied guarantee for
this manual and all information therein,
including but not limited to the implied
guarantee on marketability and
availability for some special purposes.
ITECH shall not be responsible for any
error or incidental or indirect losses
caused by the provision, use or
application of this documents and
information therein. If some guarantee
clauses in other written agreements
between ITECH and users are not
consistent with clauses herein, those
clauses in other written agreements
shall prevail.
Technology Licenses
Hardware and/or software in this
document cannot be provided without a
license and can only be used or copied
according to the license.
Restricted Rights Legend
Restricted permissions of the U.S.
government. Permissions for software
and technical data which are authorized
to the U.S. Government only include
those for custom provision to end users.
ITECH follows FAR 12.211 (technical
data), 12.212 (computer software).
DFARS 252.227-7015 (technical
data--commercial products) for national
defense and DFARS 227.7202-3
(permissions for commercial computer
software or computer software
documents) while providing the
customized business licenses of
software and technical data.
Safety Notices
A CAUTION sign denotes a
hazard. It calls attention to an
operating procedure or practice
that, if not correctly performed
or adhered to, could result in
damage to the product or loss of
important data. Do not proceed
beyond a CAUTION sign until
the indicated conditions are fully
understood and met.
A WARNING sign denotes
a hazard. It calls attention to
an operating procedure or
practice that, if not correctly
performed or adhered to, could
result in personal injury or death.
Do not proceed beyond a
WARNING sign until the
indicated conditions are fully
understood and met.
NOTE
A NOTE sign denotes important
hint. It calls attention to tips or
supplementary information that
is essential for users to refer to.

IT8300 Programming Guide
Copyright © ITECH Electronics Co., Ltd. i
Certification and Quality Assurance
IT8300 series electronic load completely reaches nominal technical indicators
in the manual.
Warranty service
ITECH Company will provide one-year warranty services for the product
materials and manufacturing (excluding the following limitations).
When warranty service or repair is needed, please send the product to the
service unit specified by ITECH Company.
When the product is sent to ITECH Company for warranty service, the
customer must pay the one-way freight to the maintenance department of
ITECH, and ITECH will be responsible for return freight.
If the product is sent to ITECH for warranty service from other countries,
the customer will be responsible for all the freight, duties and other taxes.
Limitation of Warranty
Warranty service does not apply to the damage caused in the following
circumstances:
Damage resulting from customer-wired circuits or customer-supplied parts
or accessories;
Product which has been modified or repaired by the customer;
Damage caused by the circuit installed by the customer or damage caused
by operation of the product in non-specified environment;
The product model or serial number is altered, deleted, removed or made
illegible by customer;
Damage caused by accidents, including but not limited to lightning, water,
fire, abuse or negligence.
Safety signs
DC power
ON (with the power
switched on)
AC power
OFF (with the power
supply switched off)
Both DC and AC power supply
Power supply
switching-on status
Protective grounding terminal
Power supply
switching-off status
Grounding terminal
Reference terminal
Danger sign
Positive terminal
Warning sign (refer to specific
“Warning” or “Caution”
information in the manual)
Negative terminal
Ground wire connection end
sign
-
-

IT8300 Programming Guide
Copyright © ITECH Electronics Co., Ltd. ii
Safety Precautions
General safety precautions below must be followed in each phase of instrument
operation. In case of failure to follow these precautions or specific warnings in
other parts of the manual, violation against the safety standards related to the
design, manufacture and purpose of the instrument will occur. If the user does
not follow these precautions, ITECH will bear no responsibility arising there
from.
Do not use the instrument if it is damaged. Before operation, check
the casing to see whether it cracks. Do not operate the instrument in
the presence of inflammable gasses, vapors or dusts.
The electronic load is provided with a power line during delivery and
should be connected to a junction box. Before operation, be sure that
the electronic load is well grounded.
Use electric wires of appropriate load. All loading wires should be
capable of bearing maximum short-circuit of electronic load without
overheating.
Check all marks on the instrument before connecting the instrument
to electronic load.
Ensure the voltage fluctuation of mains supply is less than 10% of the
working voltage range in order to reduce risks of fire and electric
shock.
Do not install alternative parts on the instrument or perform any
unauthorized modification.
Do not use the equipment when the removable cover is dismantled or
loose.
Please use the power adapter supplied by the manufacturer to avoid
accidental injury.
We do not accept responsibility for any direct or indirect financial
damage or loss of profit that might occur when using the instrument.
This instrument is used for industrial purposes, do not apply this
product to IT power supply system.
Do not use the equipment on the life support system or other
equipment with safety requirements.
If the equipment is not used in the manner specified by the
manufacturer, its protection may be damaged.
Always use dry cloth to clean the equipment housing. Do not clean
the inside of the instrument.
Do not block the air vent of the equipment.
Environmental conditions
The IT8300 series electronic load can only be used indoors or in low
condensation areas. The following table shows general environmental
requirements for this instrument.
Environmental conditions
Requirement

IT8300 Programming Guide
Copyright © ITECH Electronics Co., Ltd. iii
Operating temperature
0°C - 40°C
Operating humidity
20% - 80% (non condensing)
Storage temperature
-20°C - 70 °C
Altitude
Operating up to 2,000 meters
Installation category
Ⅱ
Pollution
Pollution degree 2
Note
In order to ensure the accuracy of measurement, it is recommended to operate the
instrument half an hour after start-up.
Regulation tag
The CE tag shows that the product
complies with the provisions of all relevant
European laws (if the year is shown, it
indicates that the year when the design is
approved).
This instrument complies with the WEEE
directive (2002/96/EC) tag requirements.
This attached product tag shows that the
electrical/electronic product cannot be
discarded in household waste.
This symbol indicates that no danger will
happen or toxic substances will not leak or
cause damage in normal use within the
specified period. The service life of the product
is 10 years. The product can be used safely
within the environmental protection period;
otherwise, the product should be put into the
recycling system.
Waste electrical and electronic equipment (WEEE)
directive
Waste electrical and electronic equipment (WEEE)
directive, 2002/96/EC
The product complies with tag requirements of the
WEEE directive (2002/96/EC). This tag indicates that the
electronic equipment cannot be disposed of as ordinary
household waste.
Product Category
According to the equipment classification in Annex I of
the WEEE directive, this instrument belongs to the
“Monitoring” product.
If you want to return the unnecessary instrument,
please contact the nearest sales office of ITECH.

IT8300 Programming Guide
Copyright © ITECH Electronics Co., Ltd. iv
Compliance Information
Complies with the essential requirements of the following applicable European
Directives, and carries the CE marking accordingly:
Electromagnetic Compatibility (EMC) Directive 2014/30/EU
Low-Voltage Directive (Safety) 2014/35/EU
Conforms with the following product standards:
EMC Standard
IEC 61326-1:2012/ EN 61326-1:2013 ¹²³
Reference Standards
CISPR 11:2009+A1:2010/ EN 55011:2009+A1:2010 (Group 1, Class A)
IEC 61000-4-2:2008/ EN 61000-4-2:2009
IEC 61000-4-3:2006+A1:2007+A2:2010/ EN 61000-4-3:2006+A1:2008+A2:2010
IEC 61000-4-4:2004+A1:2010/ EN 61000-4-4:2004+A1:2010
IEC 61000-4-5:2005/ EN 61000-4-5:2006
IEC 61000-4-6:2008/ EN 61000-4-6:2009
IEC 61000-4-11:2004/ EN 61000-4-11:2004
1. The product is intended for use in non-residential/non-domestic environments. Use of the
product in residential/domestic environments may cause electromagnetic interference.
2. Connection of the instrument to a test object may produce radiations beyond the specified
limit.
3. Use high-performance shielded interface cable to ensure conformity with the EMC standards
listed above.
Safety Standard
IEC 61010-1:2010/ EN 61010-1:2010

IT8300 Programming Guide
Copyright © ITECH Electronics Co., Ltd. v
Contents
Certification and Quality Assurance..........................................................................................................................1
Warranty service........................................................................................................................................................1
Limitation of Warranty..............................................................................................................................................1
Safety signs ...............................................................................................................................................................1
Safety Precautions .....................................................................................................................................................2
Environmental conditions..........................................................................................................................................2
Regulation tag............................................................................................................................................................3
Waste electrical and electronic equipment (WEEE) directive...................................................................................3
Compliance Information............................................................................................................................................4
CHAPTER1 REMOTE CONTROL ....................................................................................................................1
1.1 Overview.............................................................................................................................................................1
1.2 SCPI Command Introduction ..............................................................................................................................1
1.3 Command Type of SCPI .....................................................................................................................................1
1.4 Message Type of SCPI........................................................................................................................................3
1.5 Response Data Type............................................................................................................................................4
1.6 Command Format................................................................................................................................................5
1.7 Data Type............................................................................................................................................................7
1.8 SCPI Command Complete ..................................................................................................................................8
1.9 Remote Operation................................................................................................................................................9
1.9.1 RS232 Interface ...........................................................................................................................................9
1.9.2 USB Interface ............................................................................................................................................10
1.9.3 LAN Interface ............................................................................................................................................11
1.9.4 CAN Interface............................................................................................................................................11
1.9.5 RS485 Interface .........................................................................................................................................12
1.10 Queue ..............................................................................................................................................................12
1.11 Status byte and service request (SRQ).............................................................................................................13
1.12 Serial poll and SRQ.........................................................................................................................................14
1.13 Trigger Model (GPIB Operation)....................................................................................................................14
CHAPTER2 SCPI REGISTER ..........................................................................................................................16
2.1 Status Register...................................................................................................................................................16
2.2 Condition register..............................................................................................................................................18
2.3 Event register.....................................................................................................................................................18
2.4 Enable register...................................................................................................................................................19
CHAPTER3 ESSENTIAL COMMANDS .........................................................................................................20
STATus:QUEStionable[:EVENt]?..........................................................................................................................20
STATus:QUEStionable:ENABle ............................................................................................................................ 20
STATus:QUEStionable:PTRansition ......................................................................................................................21
STATus:QUEStionable:NTRansition .....................................................................................................................21
STATus:QUEStionable:CONDition?......................................................................................................................22
STATus:OPERation[:EVENt]?...............................................................................................................................22
STATus:OPERation:ENABle .................................................................................................................................23
STATus:OPERation:CONDition?...........................................................................................................................23
STATus:PRESet...................................................................................................................................................... 24
CHAPTER4 SYSTEM COMMANDS ...............................................................................................................25
SYSTem:POSetup...................................................................................................................................................25
SYSTem:VERSion? ................................................................................................................................................25
SYSTem:ERRor? ....................................................................................................................................................26
SYSTem:CLEar.......................................................................................................................................................26
SYSTem:LOCal ...................................................................................................................................................... 26
SYSTem:REMote....................................................................................................................................................27
SYSTem:RWLock...................................................................................................................................................27
SYSTem:BEEPer:IMMediate ................................................................................................................................. 28
SYSTem:BEEPer[:STATe].....................................................................................................................................28
SYSTem:KEY.........................................................................................................................................................28
SYSTem:COMMunicate:SELect ............................................................................................................................29
SYSTem:COMMunicate:RS232:BAUDrate...........................................................................................................29
SYSTem:COMMunicate:RS485:BAUDrate...........................................................................................................29
SYSTem:COMMunicate:LAN:CURRent:ADDRess..............................................................................................30

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Copyright © ITECH Electronics Co., Ltd. vi
SYSTem:COMMunicate:LAN:CURRent:DGATeway........................................................................................... 30
SYSTem:COMMunicate:LAN:CURRent:SMASk .................................................................................................31
SYSTem:COMMunicate:LAN:SOCKetport...........................................................................................................31
SYSTem:COMMunicate:LAN:MACaddress?........................................................................................................32
CHAPTER5 MEASURE COMMANDS............................................................................................................33
FETCh:VOLTage[:DC]?.........................................................................................................................................33
MEASure:VOLTage[:DC]? ....................................................................................................................................33
FETCh:VOLTage:MAX?........................................................................................................................................33
MEASure:VOLTage:MAX? ...................................................................................................................................33
FETCh:VOLTage:MIN? .........................................................................................................................................34
MEASure:VOLTage:MIN?.....................................................................................................................................34
FETCh:CURRent[:DC]? .........................................................................................................................................34
MEASure:CURRent[:DC]?.....................................................................................................................................34
FETCh:CURRent:MAX? ........................................................................................................................................34
MEASure:CURRent:MAX?....................................................................................................................................34
FETCh:CURRent:MIN?..........................................................................................................................................35
MEASure:CURRent:MIN? .....................................................................................................................................35
FETCh:POWer[:DC]?.............................................................................................................................................35
FETCh:CAPability? ................................................................................................................................................36
MEASure:CAPability?............................................................................................................................................36
FETCh:TIME?.........................................................................................................................................................36
MEASure:TIME?....................................................................................................................................................36
FETCh:ACMeter:EACStage? .................................................................................................................................36
FETCh:ACMeter:EACTotal?..................................................................................................................................37
CHAPTER6 TRIGGER SUBSYSTEM.............................................................................................................38
TRIGger[:IMMediate].............................................................................................................................................38
TRIGger:SOURce ...................................................................................................................................................38
TRIGger:TIMer.......................................................................................................................................................39
CHAPTER7 TRACE SUBSYSTEM..................................................................................................................40
TRACe:CLEar......................................................................................................................................................... 40
TRACe:FREE?........................................................................................................................................................40
TRACe:POINts .......................................................................................................................................................40
TRACe:FEED .........................................................................................................................................................41
TRACe:FEED:CONTrol.........................................................................................................................................41
TRACe:DATA?.......................................................................................................................................................42
TRACe:FILTer[:STATe] ........................................................................................................................................42
TRACe:DELay........................................................................................................................................................43
TRACe:TIMer.........................................................................................................................................................43
CHAPTER8 SOURCE SUBSYSTEM ...............................................................................................................45
[SOURce:]INPut[:STATe]......................................................................................................................................45
[SOURce:]INPut:SHORt[:STATe] .........................................................................................................................45
[SOURce:]INPut:TIMer[:STATe]...........................................................................................................................46
[SOURce:]INPut:TIMer:DELay .............................................................................................................................46
[SOURce:]REMote:SENSe[:STATe] .....................................................................................................................47
[SOURce:]FUNCtion ..............................................................................................................................................47
[SOURce:]FUNCtion:MODE .................................................................................................................................48
[SOURce:]TRANsient[:STATe] .............................................................................................................................49
[SOURce:]PROTection:CLEar ...............................................................................................................................49
[SOURce:]CURRent[:LEVel][:IMMediate] ...........................................................................................................49
[SOURce:]CURRent:RANGe.................................................................................................................................50
[SOURce:]CURRent:SLEW[:BOTH].....................................................................................................................51
[SOURce:]CURRent:SLEW:POSitive....................................................................................................................51
[SOURce:]CURRent:SLEW:NEGative ..................................................................................................................52
[SOURce:]CURRent:SLEWrate:STATe.................................................................................................................53
[SOURce:]CURRent:PROTection:STATe..............................................................................................................53
[SOURce:]CURRent:PROTection[:LEVel]............................................................................................................54
[SOURce:]CURRent:PROTection:DELay..............................................................................................................54
[SOURce:]CURRent:TRANsient:MODE...............................................................................................................55
[SOURce:]CURRent:TRANsient:ALEVel .............................................................................................................56

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[SOURce:]CURRent:TRANsient:BLEVel..............................................................................................................56
[SOURce:]CURRent:TRANsient:AWIDth.............................................................................................................57
[SOURce:]CURRent:TRANsient:BWIDth .............................................................................................................57
[SOURce:]CURRent:HIGH ....................................................................................................................................57
[SOURce:]CURRent:LOW.....................................................................................................................................57
[SOURce:]VOLTage[:LEVel][:IMMediate]........................................................................................................... 58
[SOURce:]VOLTage:RANGe.................................................................................................................................58
[SOURce:]VOLTage[:LEVel]:ON..........................................................................................................................59
[SOURce:]VOLTage:LATCh[:STATe]..................................................................................................................60
[SOURce:]VOLTage:HIGH....................................................................................................................................60
[SOURce:]VOLTage:LOW.....................................................................................................................................60
[SOURce:]VOLTage[:LEVel]:ON:HYSTeresis..................................................................................................61
[SOURce:]RESistance[:LEVel][:IMMediate].........................................................................................................61
[SOURce:]RESistance:RANGe...............................................................................................................................62
[SOURce:]RESistance:HIGH..................................................................................................................................63
[SOURce:]RESistance:LOW ..................................................................................................................................63
[SOURce:]POWer[:LEVel][:IMMediate] ...............................................................................................................63
[SOURce:]POWer:RANGe.....................................................................................................................................64
[SOURce:]POWer:HIGH........................................................................................................................................64
[SOURce:]POWer:LOW.........................................................................................................................................64
[SOURce:]POWer:PROTection[:LEVel]................................................................................................................65
[SOURce:]POWer:PROTection:DELay..................................................................................................................66
[SOURce:]POWer:CONFig[:LEVel]......................................................................................................................66
[SOURce:]INPut:CONTrol <EXTernal/INTernal> ................................................................................................67
[SOURce:]ACMeter:EACStage:CLEar ..................................................................................................................67
CHAPTER9 LIST COMMANDS.......................................................................................................................68
[SOURce:]LIST:RANGe ........................................................................................................................................68
[SOURce:]LIST:COUNt .........................................................................................................................................68
[SOURce:]LIST:STEP............................................................................................................................................69
[SOURce:]LIST:SLOWrate[:STATe] <LOW|HIGH>............................................................................................ 69
[SOURce:]LIST:LEVel? .........................................................................................................................................70
[SOURce:]LIST:SLEW[:BOTH]............................................................................................................................ 70
[SOURce:]LIST:WIDth ..........................................................................................................................................71
[SOURce:]LIST:SAV .............................................................................................................................................71
[SOURce:]LIST:RCL..............................................................................................................................................72
CHAPTER10 CALIBRATION COMMANDS ...................................................................................................73
CALibrate:SECure[:STATe]...................................................................................................................................73
CALibrate:INITial...................................................................................................................................................73
CALibrate:SAVe.....................................................................................................................................................74
CALibrate:CURRent:POINt....................................................................................................................................74
CALibrate:CURRent[:LEVel].................................................................................................................................75
CALibrate:CURRent:METEr:POINt ......................................................................................................................75
CALibrate:CURRent:METEr[:LEVel] ...................................................................................................................75
CALibrate:VOLTage:POINt...................................................................................................................................76
CALibrate:VOLTage[:LEVel] ................................................................................................................................76
CALibrate:VOLTage:METEr:POINt......................................................................................................................77
CALibrate:VOLTage:METEr[:LEVel]...................................................................................................................77
CALibration:STRing...............................................................................................................................................78
CALibration:STRing? .............................................................................................................................................78
CHAPTER11 IEEE488.2 COMMANDS .............................................................................................................79
*CLS - Clear Status.................................................................................................................................................80
*ESE <NRf> - Event Enable...................................................................................................................................80
*ESR?......................................................................................................................................................................81
*IDN?......................................................................................................................................................................81
*OPC.......................................................................................................................................................................81
*PSC........................................................................................................................................................................82
*RCL.......................................................................................................................................................................83
*RST .......................................................................................................................................................................83
*SAV.......................................................................................................................................................................83
*SRE .......................................................................................................................................................................84

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*STB?......................................................................................................................................................................84
*TRG.......................................................................................................................................................................85
*TST?......................................................................................................................................................................85
*WAI.......................................................................................................................................................................85
CHAPTER12 ERROR INFORMATION............................................................................................................87

Remote Control
Copyright © ITECH Electronics Co., Ltd. 1
Chapter1 Remote Control
1.1 Overview
This chapter will provide following remote configuration introductions:
SCPI Command Introduction
Command type
Command format
Data format
Remote operation
1.2 SCPI Command Introduction
Standard Command for Programmable Instrumentation (SCPI) is a
programming language for controlling instrument functions via GPIB, RS-232,
USB, and Ethernet interfaces. SCPI is placed on the top of the IEEE 488.2
hardware section. The same SCPI commands and parameters control the
same function of different machines.
1.3 Command Type of SCPI
SCPI has two types of commands, common and subsystem.
Common commands generally are not related to specific operation but to
controlling overallelectronic load functions, such as reset, status, and
synchronization. All commoncommands consist of a three-letter mnemonic
preceded by an asterisk: *RST *IDN? *SRE 8.
Subsystem commands perform specific electronic load functions. They are
organized into an inverted tree structure with the "root" at the top. The
following figure shows a portion of a subsyste command tree, from which
you access the commands located along the various paths.
Multiple commands in a message
Multiple SCPI commands can be combined and sent as a single
message with one message terminator. There are two important
considerations when sending several commands within a single
message:
Use a semicolon to separate commands within a message.
Head paths influence how the instrument interprets commands.
We consider the head path as a string which will be inserted in front of

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Copyright © ITECH Electronics Co., Ltd. 2
every command of a message. As for the first command of a message,
the head path is a null string; for each subsequent command, the head
path is a string which is defined to form the current command until and
including the head of the last colon separator. A message with two
combined commands: CURR:LEV 3;PROT:STAT OFF
The example indicates the effect of semicolon and explains the concept
of head path. Since the head path is defined to be "CURR" after "curr: lev
3", the head of the second command, "curr", is deleted and the
instrument explains the second command as: CURR:PROT:STAT OFF
If "curr" is explicitly included in the second command, it is semantically
wrong. Since combining it with the head path will become
"CURR:CURR:PROT:STAT OFF", resulting in wrong command.
Movement in the subsystem
In order to combine commands from different subsystems, you need to
be able to reset the header path to a null string within a message. You do
this by beginning the command with a colon (:), which discards any
previous header path. For example, you could clear the output protection
and check the status of the Operation Condition register in one message
by using a root specifier as follows:
PROTection:CLEAr;:STATus:OPERation:CONDition?
The following message shows how to combine commands from different
subsystems as well as within the same subsystem:
POWer:LEVel 200;PROTection 28; :CURRent:LEVel 3;PROTection:STATe ON
Note the use of the optional header LEVel to maintain the correct path
within the voltage and current subsystems, and the use of the root
specifier to move between subsystems.
Including Common Commands
You can combine common commands with subsystem commands in the
same message. Treat the common command as a message unit by
separating it with a semicolon (the message unit separator). Common
commands do not affect the header path; you may insert them anywhere
in the message.
VOLTage:TRIGgered 17.5;:INITialize;*TRG
OUTPut OFF;*RCL 2;OUTPut ONIT872X-3X SCPI Communication protocol 17
Case sensitivity
Common commands and SCPI commands are not case sensitive. You
can use upper or lower, for example:
*RST = *rst
:DATA? = :data?
:SYSTem:PRESet = :system:preset
Long-form and short-form versions
A SCPI command word can be sent in its long-form or short-form version.
The command subsystem tables in Section 5 provide the in the
long-form version. However, the short-form version is indicated by upper
case characters. Examples:

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:SYSTem:PRESet long-form
:SYST:PRES short form
:SYSTem:PRES long-form and short-form combination
Note that each command word must be in long-form or short-form, and
not something in between.
For example, :SYSTe:PRESe is illegal and will generate an error. The
command will not be executed.
Query Observe the following precautions with queries:
Set up the proper number of variables for the returned data. For example, if
you are reading back a measurement array, you must dimension the array
according to the number of measurements that you have placed in the
measurement buffer.
Read back all the results of a query before sending another command to
the electronic load. Otherwise a Query Interrupted error will occur and the
unreturned data will be lost.
1.4 Message Type of SCPI
There are two types of SCPI messages, program and response.
Program message: A program message consists of one or more properly
formatted SCPI commands sent from the controller to the electronic load.
The message, which may be sent at any time, requests the electronic load
to perform some action.
Response message: A response message consists of data in a specific
SCPI format sent from the electronic load to the controller. The electronic
load sends the message only when commanded by a program message
called a "query."
The next figure illustrates SCPI message structure:
The Message Unit
The simplest SCPI command is a single message unit consisting of a command
header (or keyword) followed by a message terminator. The message unit may
include a parameter after the header. The parameter can be numeric or a
string.
VOLTage 20<NL>

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Headers Headers, also referred to as keywords, are instructions recognized by the
electronic load. Headers may be either in the long form or the short form. In the
long form, the header is completely spelled out, such as VOLTAGE, STATUS,
and DELAY. In the short form, the header has only the first three or four letters,
such as VOLT, STAT, and DEL.
Query Indicator
Following a header with a question mark turns it into a query (VOLTage?,
VOLTage:PROTection?). If a query contains a parameter, place the query
indicator at the end of the last header(VOLTage:PROTection?MAX).
Message Unit Separator
When two or more message units are combined into a compound message,
separate the units with a semicolon (STATus:OPERation?;QUEStionable?).
Root Specifier When it precedes the first header of a message unit, the colon becomes the
root specifier. It tells the command parser that this is the root or the top node of
the command tree.
Message Terminator
A terminator informs SCPI that it has reached the end of a message. Three
permitted message terminators are:
newline (<NL>),decimal 10 or hexadecimal 0X0Ain ASCII.
end or identify (<END>)
both of the above (<NL><END>).
In the examples of this guide, there is an assumed message terminator at the
end of each message.
Command execution rules
Commands execute in the order that they are presented in the program
message.
An invalid command generates an error and, of course, is not executed.
Valid commands that precede an invalid command in a multiple command
program message are executed.
Valid commands that follow an invalid command in a multiple command
program message are ignored.
1.5 Response Data Type
Character strings returned by query statements may take either of the following
forms, depending on the length of the returned string:
<CRD> Character Response Data. Permits the return of character strings.
<AARD> ArbitraryASCII Response Data. Permits the return of undelimited 7-bit
ASCII. This data type has an implied message terminator.
<SRD> String Response Data. Returns string parameters enclosed in double quotes

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Response messages
A response message is the message sent by the instrument to the computer in
response to aquery command.
Sending a response message
Afte sending a query command, the response message is placed in the Output
Queue. When the IT8300 series is then addressed to talk, the response
message is sent from the Output Queue to the computer.
Multiple response messages
If you send more than one query command in the same program message (see
the paragraph entitled, “ Multiple Command Messages “), the multiple response
messages for all the queries is sent to the computer when the IT8300 series is
addressed to talk. The responses are sent in the order that the query
commands were sent and are separated by semicolons (;). Items within the
same query are separated by commas (,). The following example shows the
response message for a program message that contains four single item query
commands:
0; 1; 1; 0
Response message terminator (RMT)
Each response is terminated with an LF (line feed) and EOI (end or identify).
The following example shows how a multiple response message is terminated:
0; 1; 1; 0; <RMT>
Message exchange protocol
Two rules summarize the message exchange protocol:
Rule 1.You must always tell the IT8300 series what to send to the computer.
The following two steps must always be performed to send information from the
instrument other computer:
1. Send the appropriate query command(s) in a program message.1.
2. Address the IT8300 series to talk.
Rule 2.The complete response message must be received by the computer
before another program message can be sent to the IT8300 series.
1.6 Command Format
Formats for command display are as follows:
[SOURce[1|2]:]VOLTage:UNIT {VPP|VRMS|DBM}
[SOURce[1|2]:]FREQuency:CENTer
{<frequency>|MINimum|MAXimum|DEFault}
Based on the command syntax, most commands (and certain Parameter) are
expressed in both upper and lower cases. Upper case refers to abbreviation of
commands. Shorter program line may send commands in abbreviated format.
Long-format commands may be sent to ensure better program readability.
For example, both formats of VOLT and VOLTAGE are acceptable in the above
syntax statements. Upper or lower case may be used. Therefore, formats of
VOLTAGE, volt and Volt are all acceptable. Other formats (such as VOL and
VOLTAG) are invalid and will cause errors.
Parameter options with given command strings are included in the brace
({ }). The brace is not sent along with command strings.

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Vertical stripes (|) separate several parameter options with given command
strings. For example, {VPP|VRMS|DBM} indicates that you may assign
"APP", "VRMS" or "DBM" in the above commands. Vertical stripes are not
sent along with command strings.
Angle brackets (< >) in the second example indicates that a value must be
assigned to the parameter in the brace. For example, the parameter in the
angle bracket is <frequency> in the above syntax statements. Angle
brackets are not sent along with command strings. You must assign a value
(such as "FREQ:CENT 1000") to the parameter, unless you select other
options displayed in the syntax (such as "FREQ:CENT MIN").
Some syntax elements (such as nodes and Parameter) are included in
square brackets ([ ]). It indicates that these elements can be selected and
omitted. Angle brackets are not sent along with command strings. If no
value is assigned to the optional Parameter, the instrument will select a
default value. In the above examples, "SOURce[1|2]" indicates that you
may refer to source channel 1 by "SOURce" or "SOURce1" or "SOUR1" or
"SOUR". In addition, since the whole SOURce node is optional (in the
square bracket), you can refer to the channel 1 by omitting the whole
SOURce node. It is because the channel 1 is the default channel for
SOURce language node. On the other hand, if you want to refer to channel
2, "SOURce2" or "SOUR2" must be used in the program line.
Colon (:) It is used to separate key words of a command with the key words in next level.
As shown below:
APPL:SIN 455E3,1.15,0.0
In this example, APPLy command assigns a sine wave with frequency of 455
KHz, amplitude of 1.15 V and DC offset of 0.0 V.
Semicolon (;) It is used to separate several commands in the same subsystem and can also
minimize typing. For example, to send the following command string:
TRIG:SOUR EXT; COUNT 10
has the same effect as sending the following two commands:
TRIG:SOUR EXT
TRIG:COUNT 10
Question mark (?)
You can insert question marks into a command to query current values of most
Parameter. For example, the following commands will trigger to set the count as
10:
TRIG:COUN 10
Then, you may query count value by sending the following command:
TRIG:COUN?
You may also query the allowable minimum or maximum count as follows:
TRIG:COUN?MIN
TRIG:COUN?MAX
Comma (,) If a command requires several Parameter, then a comma must be used to
separate adjacent Parameter.

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Space You must use blank characters, [TAB] or [Space] to separate Parameter with
key words of commands.
Generic commands (*)
Execute functions like reset, self inspection and status operation. Generic
commands always start with a asterisk (*) and occupy 3 character sizes,
including one or more Parameter. Key words of a command and the first
parameter are separated by a space. Semicolon (;) can separate several
commands as follows:
*RST; *CLS; *ESE 32; *OPC?
Command terminator
Command strings sent to the instrument must end with a <Newline> (<NL>)
character. IEEE-488 EOI (End or Identify) information can be used as <NL>
character to replace termination command string of <NL> character. It is
acceptable to place one <NL> after a <Enter>. Termination of command string
always resets current SCPI command path to root level.
NOTE
As for every SCPI message with one query sent to the instrument, the
instrument will use a <NL> or newline sign (EOI) to terminate
response of return. For example, if "DISP:TEXT?" is sent, <NL> will
be placed after the returned data string to terminate response. If an
SCPI message includes several queries separated by semicolon
(such as "DISP?;DISP:TEXT?"), <NL> will terminate response
returned after response to the last query. In all cases, the program
must read <NL> in response before another command is sent to the
instrument, otherwise errors will be caused.
1.7 Data Type
SCPI language defines several data types used for program message and
response messages.
Numerical parameter
Commands requiring numerical Parameter support the notations of all common
decimal notations, including optional signs, decimal points, scientific notation,
etc. Special values of numerical Parameter are also acceptable, such as MIN,
MAX and DEF. In addition, suffixes for engineering units can also be sent
together with numerical Parameter (including M, k, m or u). If the command
accepts only some specific values, the instrument will automatically round the
input Parameter to acceptable values. The following commands require
numerical Parameter of frequency value:
[SOURce[1|2]:]FREQuency:CENTer {<Frequency>|MINimum|MAXimum}
<NR1>: There is an implicit decimal point in the last bit,such as 273
<NR2>: There is an explicit decimal point,such as .273
<NR3>: There are an explicit decimal point and exponential,such as
2.73E+22.73E+2
<Nrf>:The extensible form includes <NR1>, <NR2> and <NR3>,such
as 273 273. 2.73E2273 273. 2.73E2
<Nrf+>: The extensible decimal form includes <NRf> and MIN MAX
DEF, such as 273 273. 2.73E2 MAX. MIN and MAX are the minimum
and maximum finite number. Within the range of the parameter

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definition, DEF is the default of the parameter.
Discrete parameter
Discrete Parameter are used for settings with limited number of programming
values (such as IMMediate, EXTernal or BUS). They can use short and long
format like key words of commands. They may be expressed in both upper and
lower case. The query response always returns uppercase Parameter in short
format. The following commands require discrete Parameter in voltage unit:
[SOURce[1|2]:]VOLTage:UNIT {VPP|VRMS|DBM}
Boolean parameter
Boolean Parameter refer to true or false binary conditions. In case of false
conditions, the instrument will accept "OFF" or "0". In case of true conditions,
the instrument will accept "ON" or "1". In query of Boolean settings, the
instrument will always return "0" or "1". Boolean Parameter are required by the
following commands:
DISPlay {OFF|0|ON|1}
ASCII string Parameter
String Parameter may actually include all ASCII character sets. Character
strings must start and end with paired quotation marks; and single quotation
marks or double quotation marks are both allowed. Quotation mark separators
may also act as one part of a string, they can be typed twice without any
character added between them. String parameter is used in the following
command:
DISPlay:TEXT <quoted string>
For example, the following commands display message of "WAITING..."
(without quotation marks) on the front panel of the instrument.
DISP:TEXT "WAITING..."
Single quotation marks may also be used to display the same message.
DISP:TEXT 'WAITING...'
1.8 SCPI Command Complete
SCPI commands sent to the electronic load are processed either sequentially
or in parallel. Sequential commands finish execution before a subsequent
command begins. Parallel commands allow other commands to begin
executing while the parallel command is still executing. Commands that affect
trigger actions are among the parallel commands.
*WAI, *OPC, and *OPC:Common commands provide different ways of
indicating when all transmitted commands, including any parallel ones, have
completed their operations. Some practical considerations for using these
commands are as follows:
*WAI: This prevents the electronic load from processing subsequent
commands until all pending operations are completed.
*OPC?: This places a 1 in the Output Queue when all pending operations have
completed. Because it requires your program to read the returned value before
executing the next program statement, *OPC? can be used to cause the
controller to wait for commands to complete before proceeding with its
program.
*OPC: This sets the OPC status bit when all pending operations have
completed. Since your program can read this status bit on an interrupt basis,
*OPC allows subsequent commands to be executed.
Note
The trigger system must be in the Idle state in order for the status OPC bit to be true.

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Therefore, as far as triggers are concerned, OPC is false whenever the trigger
system is in the Initiated state.
Using Device Clear
You can send a device clear at any time to abort a SCPI command that may be
hanging up the GPIB interface. The status registers, the error queue, and all
configuration states are left unchanged when a device clear message is
received. Device clear performs the following actions:
The input and output buffers of the electronic load are cleared.
The electronic load is prepared to accept a new command string.
The following statement shows how to send a device clear over the GPIB
interface using GW BASIC:
CLEAR 705 IEEE-488 Device Clear
The following statement shows how to send a device clear over the GPIB
interface using the GPIB command library for C or QuickBASIC.
IOCLEAR (705)
1.9 Remote Operation
IT8300 series have five standard communication interfaces: RS232, USB,
RS485, LAN and CAN. The customer can choose any one according to his
demands.
1.9.1 RS232 Interface
Cable connection load with both ends of COM interface (DB9) and computer.
Composite key [Shift] + 8(System) on front board can be used to enter system
menu for activation.
In RS-232 interface, all SCPI commands can be used for programming. If
RS-232 interface is selected, in accordance with internal connection of data
terminal equipment (DTE) and data communication equipment (DCE) as
defined in EIARS-232, the load is connected to another DTE (e.g., PC COM
interface) with direct-connected Modem cable.
Note
The setup of RS232 in the program must be consistent with the system setup of the instrument.
Press [Shift] + 8(System) to modify the setup of the instrument if they don’t match.
RS-232 data format
RS-232 data comprises start bit, odd and even parity check bit, stop bit and
8-bit data bit. Start bit and stop bit are not editable. However, next odd or even
item can be selected by front board [Shift] + 8(System). The odd and even
items are saved in NVM.
Baud rate Through front board [Shift] + 8(System), the user may select one Baud rate
saved in NVM: 4800 /9600 /19200 /38400 /57600 /115200
RS-232 Connection
Use RS-232 cable with DB-9 interface because the RS-232 serial port can be
connected controller (e.g. PC) serial port. Do not use modulating cable of
air-conditioner. Refer to Table 2-2 for plug pin.
If your computer is provided with a RS-232 interface with DB-25 plug, a cable
and a adapter with DB-25 plug (one end) and DB-9 plug (the other end) are

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required (not the modulating cable of the air-conditioner).
RS232 Pins of Plug
Base pin
number
Description
1
No conjunction
2
TXD, data transmission
3
RXD, data receiving
4
No conjunction
5
GND, grounding
6
No conjunction
7
CTS, clear to send
8
RTS, request to send
9
No conjunction
RS-232 troubleshooting:
In case of connection failure of RS-232, perform following check:
Check if the computer and load are provided with same Baud rate, parity
check bit, data bit and flow control. The power shall be configured with one
start bit (fixed) and one stop bit (fixed).
Just as described in the RS-232 connector, correct interface cable or
adapter shall be adopted. Note: even if the cable is equipped with right plug,
internal wiring may be incorrect.
The interface cable must be connected to the correct serial port (COM1,
COM2, etc.) of the computer.
Setting of communication
Before communication operation, be sure to match load and PC parameters (as
follows).
Baud rate: 9600 (4800/9600/19200/38400/57600/15200). You may enter
system menu through the board to set communication Baud rate.
Data bit: 8 bits
Stop bit: 1 bit
Check: (none, even, odd)
EVEN 8 data bits have even-parity check
ODD 8 data bits have odd-parity check
NONE 8 data bits have no check
Local address: (0-31, factory set value: 0)
Start Bit
Parity=None
8 Data Bits
Stop Bit
1.9.2 USB Interface
Connect the load and the computer using a cable with two USB interfaces
(each end). All functions of the load can be programmed via USB.
The functions of load USB488 interface are as follows:
The interface is 488.2 USB488 Interface.
The interface receives requests of REN_CONTROL, GO_TO_LOCAL and
LOCAL_LOCKOUT.