I-Tech IT8500plus Series User manual

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IT8500+ Series Frame Format
Programmable DC Electronic Load
Models IT8500+
© Copyright 2005 All Rights Reserved
Ver1.1/MAR, 2008/8500-401

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Directory
Warranty Information............................................................................................................................... 3
Safety Summary....................................................................................................................................... 3
Chapter 1 Remote Operation Mode........................................................................................................ 5
1.1 Communication Modules Introduction ............................................................................5
1.2 Communication with PC.................................................................................................7
Chapter 2 Communication Order for IT8500+ ....................................................................................... 9
Frame Format......................................................................................................................9
Communication Protocol....................................................................................................13

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Warranty Information
Certification
We certify that this product met its published specifications at time of shipment from the factory.
Warranty
This hardware product is warranted against defects in material and workmanship for a period of
ONE year from date of delivery. IT8500 series electronic load for use with a hardware product and
when properly installed on that hardware product, are warranted not to fail to execute their
programming instructions due to defects in material and workmanship for a period of 90 days from
date of delivery. During the warranty period our company will either repair or replace products which
prove to be defective. Our company does not warranty that the operation for the software firmware
or hardware shall be uninterrupted or error free.
For warranty service, with the exception of warranty options, this product must be returned to a
service facility designated by our company. Customer shall prepay shipping charges by (and shall
pay all duty and taxes) for products returned to our place for warranty service. Our company shall
pay for return of products to Customer.
Limitation of Warranty
The foregoing warranty shall not apply to defects resulting from improper or inadequate
maintenance by the Customer, Customer-supplied software or interfacing, unauthorized
modification or misuse, operation outside of the environmental specifications for the product, or
improper site preparation and maintenance.
Assistance
The above statements apply only to the standard product warranty. Warranty options product
maintenance agreements and customer assistance agreements are also available.
Safety Summary
The following general safety precautions must be observed during all phases of operation of this
instrument. Failure to comply with these precautions or with specific warnings elsewhere in this
manual violates safety standards of design, manufacture, and intended use of the instrument .We
assumes no liability for the customer’s failure to comply with these requirements.
Environmental Conditions
This instrument is intended for indoor use. Pollution degree 2 environments. It is designed to
operate at a maximum relative humidity of 95% and at altitudes of up to 2000 meters. Refer to the
specifications tables for the ac mains voltage requirements and ambient operating temperature
range.
Before Applying Power
Verify that all safety precautions are taken. Note the instrument's external markings described under
"Safety Symbols".

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Ground the Instrument
This product is a Safety Class 1 instrument (provided with a protective earth terminal). To minimize
shock hazard, the instrument chassis and cover must be connected to an electrical ground. The
instrument must be connected to the ac power mains through a grounded power cable, with the
ground wire firmly connected to an electrical ground (safety ground) at the power outlet. Note: Any
interruption of the protective (grounding) conductor or disconnection of the protective earth terminal
will cause a potential shock hazard that could result in personal injury.
DO NOT OPERATE IN AN EXPLOSIVE ATMOSPHERE
Do not operate the instrument in the presence of fumes or flammable gases.
KEEP AWAY FROM LIVE CIRCUITS
Operating personnel must not remove instrument covers except as instructed in this Guide for
installing or removing electronic load modules. Component replacement and internal adjustments
must be made only by qualified service personnel. Do not replace components with power cable
connected. Under certain conditions dangerous voltages may exist even with the power cable
removed. To avoid injuries always disconnect power, discharge circuits, and remove external
voltage sources before touching components.
DO NOT SERVICE OR ADJUST ALONE
Do not try to do some internal service or adjustment unless another person capable of rendering
first aid resuscitation is present.
Safety Symbols
Direct current
Alternating current
Both direct and alternating current
Protective earth (ground) terminal
Caution (refer to accompanying documents)
The WARNING sign denotes a hazard. It calls attention to a procedure, practice, or the like, which, if
not correctly performed or adhered to, could result in personal injury. Do not proceed beyond a
WARNING sign until the indicated conditions are fully understood and met.
The CAUTION sign denotes a hazard. It calls attention to an operating procedure, or the like, which,
if not correctly performed or adhered to, could result in damage to or destruction of part or all of the
WARNING
CAUTION

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Chapter 1 Remote Operation Mode
DB9 in the rear panel of electronic load could connect with RS-232 through a TTL connector. The
following information may help you to know how to control the electronic load through PC.
1.1 Communication Modules Introduction
DB9 in the rear panel of the DC load IT8511+/IT8511A+/IT8511B+/IT8512+
/IT8512A+/IT8512B+/IT8512C+/IT8512H+/IT8513A+/IT8513C+ is TTL level,
which can be connected to the serial port of the PC through the level
conversion of the accessory. The communication module is
IT-E121/IT-E121A/IT-E122/IT-E123.
IT8513B+/IT8514B+/IT8514C+/IT8516C+ comes standard with RS232 and
USB communication interfaces, no need to purchase
IT-E121/IT-E121A/IT-E122/IT-E123.
Please do not connect the standard RS232 cable to the
IT8511+/IT8511A+/IT8511B+/IT8512+/IT8512A+/IT8512B+/IT851
2C+/IT8512H+/IT8513A+/IT8513C+ electronic load, which may
damage the instrument.
IT-E121 Communication Module
The DB9 interface connector on the rear panel of the DC load is TTL voltage
level; You can use IT-E121 communication module and IT-E121's own RS232
extension cable to connect the DB9 interface connector of the DC load and
the RS-232 interface connector of the computer for communication.

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IT-E121A Communication Module
The DB9 interface connector on the rear panel of the DC load is TTL voltage
level; IT-E121A is derived from IT-E121 (not including communication cable).
The main difference is that the DB9 female connector on the RS232 end is
converted to a male connector.
IT-E121A communication cable
IT-E122 Communication Module
The DB9 interface connector on the rear panel of the DC load is TTL voltage
level; IT-E122 has a USB interface (male connector B) on one end, you can
use IT-E122 and a standard USB extension cable (type B female connector at
one end and typeA at one end) to connect the DB9 interface connector of the
DC load and the USB interface connector of computer for the communication.
After connecting the load and computer by USB, you need to install IT-E122
driver (download from ITECH official website or contact ITECH agent). The
device manager of PC will display ‘Prolific USB-to-Serial COM Port’ after
installing.
IT-E123 Communication Module
The DB9 interface connector on the rear panel of the DC load is TTL voltage
level;
The interface on both side port of IT-E123 are DB9 interface and RS485

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interface, you can use the communication module IT-E123 and an a standard
RS485-RS232 conversion cable to connect the DB9 interface connector of
the DC load and the RS-232 interface connector of computer for the
communication.
RS485 pins
1.2 Communication with PC
Before using the remote operation mode, please make sure that the baud rate
and communication address in the DC load are the same as in the computer
software, otherwise, the communication will fail, you can change the baud
rate and communication address from the front panel or from computer.
DB9 Serial Port
In order for the computer to communicate with the DC load, both must be set
to the same RS-232 settings. These communication settings are:
1. Baud rate: 4800,9600,19200 and 38400 are selectable, default setting is
9600.
2. Data bit: 8 bit
3. Stop bit: 1
4. Parity: None
5. Address: the range is from 0 to 31, default setting is 0
Start Bit
8 Data Bits
Parity=None
Stop Bit

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RS-232 IT8513B+/IT8514B+/IT8514C+/IT8516C+ electronic load has a DB9 interface
on rear panel. Connect E-load and computer by cable of COM ends (DB9).
Composite key [Shift] + [8] on front board can be used to enter system menu
for activation.
⚫RS-232 Interface
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 EIA RS-232, the load is connected to another DTE (e.g., PC COM
interface) with direct-connected Modem cable.
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
⚫Communication Setup
Please ensure the PC and the load have the same configuration in the
following items.
Baudrate: 9600(4800, 9600, 19200, 38400). You could enter the system
menu to set the baudrate.
Data bit: 8
Stop bit: 1
Parity bit: (none, even, odd)

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EVEN 8 data bits have even parity
ODD 8 data bits have odd parity
NONE 8 data bits have no parity
Native machine address: (0 ~31, factory default is 0)
Start Bit
8 Data Bits
Parity=None
Stop Bit
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.
After connecting the load and computer by USB, you need to install IT-E122
driver (download from ITECH official website or contact ITECH agent). The
device manager of PC will display ‘Prolific USB-to-Serial COM Port’ after
installing.
Notes: Only IT8513B+/IT8514B+/IT8514C+/IT8516C+ models have the USB
communication interface. After the driver is installed successfully, use USB
line to connect in communication. (Please don’t connect DB9 interface at the
same time). Don’t need to set the menu.
Chapter 2 Communication Order for IT8500+
Frame Format
Frame length is 26 bytes. Details as following:
AAH
Address
Command
4—25bytes are information content
Parity code
Description ：
1．Start bit is AAH，occupies one byte.
2．Address range from 0 to 31, occupies one byte. 0XFF is boardcast address.
3．Each command occupies one byte. Following is the command details.
20H
Set the Remote control mode
21H
Set the input on/off state
22H
Set the max input voltage
23H
Enquire the max setup input voltage.
24H
Set max input current
25H
Enquire the max setup input current.
26H
Set max input power.
27H
Enquire the max setup input power.
28H
Set CC/CV/CW/CR operation mode of electronic load.

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29H
Enquire the operation mode.
2AH
Set CC mode current value
2BH
Enquire CC mode current value
2CH
Set CV mode voltage value
2DH
Enquire CV mode voltage value
2EH
Set CW mode watt value
2FH
Enquire CW mode watt value
30H
Set CR mode resistance value
31H
Enquire CR mode resistance value
32H
Set CC mode transient current and timer parameter.
33H
Enquire CC mode transient parameter
34H
Set CV mode transient voltage and timer parameter.
35H
Enquire CV mode transient parameter
36H
Set CW mode transient watt and timer parameter
37H
Enquire CW mode transient parameter
38H
Set CR mode transient resistance and timer parameter
39H
Enquire CR mode transient parameter
3AH
Set the list operation mode (CC )
3BH
Enquire the list operation mode.
3CH
Set the list repeat mode (ONCE / REPEAT)
3DH
Enquire the list repeat mode.
3EH
Set list steps counts.
3FH
Enquire list steps counts
40H
Set one of the step’s current and time values.
41H
Enquire one of the step’s current and time values.
4CH
Save list file in appointed area.
4DH
Recall the list file from the appointed area.
50H
Set timer value of FOR LOAD ON
51H
Enquire timer value of FOR LOAD ON
52H
Disable/Enable timer of FOR LOAD ON
53H
Enquire timer state of FOR LOAD ON
54H
Set communication address
55H
Enable/Disable LOCAL control button.
56H
Enable/Disable remote sense mode.
57H
Enquire the state of remote sense mode.
58H
Set trigger source.
59H
Enquire trigger source.
5AH
Sending a trigger signal to trigging the electronic load.
5BH
Saving user’s setting value in appointed memory area for recall.
5CH
Recall user’s setting value in appointed memory area.
5DH
Set function mode(FIXED/SHORT/TRAN/LIST/BATTERY).
5EH
Enquire function mode state.
5FH
enquire input voltage, current, power and relative state
01H
Get the information of E-Load(rated current/voltage,min voltage,max power,max

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resistance,min resistance)
02H
Set hardware OPP point
03H
Enquire hardware OPP point
80H
Set software OCP point
81H
Enquire software OCP point
82H
Set OCP delay time
83H
Enquire OCP delay time
84H
Enable/disable OCP function
85H
Enquire the state of OCP function
86H
Set software OPP point
87H
Enquire software OPP point
88H
Set software OPP delay time
89H
Enquire software OPP delay time
8AH
Set the first measuring point
8BH
Enquire the first measuring point
8CH
Set the second measuring point
8DH
Enquire the second measuring point
8EH
Set Vd value of CR-LED mode
8FH
Enquire Vd value of CR-LED mode
90H
Clear the protection state
91H
Enable/disable voltage autorange function
92H
Enquire the state of voltage autorange
93H
Enable/disable CR-LED function
94H
Enquire the state of CR-LED mode
9DH
Provide a trigger signal,nomatter what the current trigger source it is.
A0H
Read related information of E-load(working time,the rest time of the timer)
A1H
Read related information of E-load(max input voltage and current,min input votage
and current)
A2H
Catch the max measuring voltage in list mode
A3H
Catch the min measuring voltage in list mode
A4H
Catch the max measuring current in list mode
A5H
Catch the min measuring current of E-load
A6H
enquire the capacitance
B0H
Set current rising slope
B1H
Enquire current rising slope
B2H
Set current falling slope
B3H
Enquire current falling slope
B4H
Set the voltage upper limit in CC mode
B5H
Enquire the voltage upper limit in CC mode
B6H
Set the voltage lower limit in CC mode
B7H
Enquire the voltage lower limit in CC mode
B8H
Set the current upper limit in CV mode
B9H
Enquire the current upper limit in CV mode
BAH
Set the current lower limit in CV mode

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BBH
Enquire the current lower limit in CV mode
BCH
Set the voltage upper limit in CP mode
BDH
Enquire the voltage upper limit in CP mode
BEH
Set the voltage lower limit in CP mode
BFH
Enquire the voltage lower limit in CP mode
C0H
Set the max input resistance
C1H
Enquire the max input resistance
C2H
Set the voltage upper limit in CR mode
C3H
Enquire the voltage upper limit in CR mode
C4H
Set the voltage lower limit in CR mode
C5H
Enquire the voltage lower limit in CR mode
C6H
Set the current range in list mode
C7H
Enquire the current range in list mode
D0H
Set step counts of autotest file
D1H
Enquire step counts of autotest file
D2H
Set short steps
D3H
Read short steps
D4H
Set pause steps
D5H
Enquire pause steps
D6H
Set the on-load time of single step
D7H
Enquire the on-load time of single step
D8H
Set the delay time of single step
D9H
Enquire the delay time of single step
DAH
Set the no-load time of single step
DBH
Enquire the no-load time of single step
DCH
Set autotest stop condition
DDH
Enquire autotest stop condition
DEH
Set autotest chain file
DFH
Enquire autotest chain file
E0H
Save autotest file
E1H
Recall autotest file
0EH
Set Von mode
0FH
Enquire Von mode
10H
Set Von point
11H
Enquire Von point
If control output of electronic through PC, please setting electronic load to PC control state.
Command is 20H.
4．From 4th byte to 25th byte are information contents.
5．26th is checksum code, is the sum of the former 25 bytes.
NOTE

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Communication Protocol
1. Set control mode（20H）
1st byte
Start bit ( AAH )
2nd byte
Address (0—31,0XFF)
3rd byte
Command（20H）
4th .byte
Operation mode（0 is front panel operation mode ，1 is remote operation mode ）
From 5th to 25th byte
System reserve
26th byte
Sum code
Front panel operation state is not in effect if electronic load is in calibration mode.
2. Set the input on/off state （21H）
1st byte
Start bit ( AAH )
2nd byte
Address(0—31,0XFF)
3rd byte
Command（21H）
4th byte
Input state（0 is OFF，1is ON）
From 5th to 25th byte
System reserve
From26th byte
Sum code
3. Set / Read max input voltage（22H/23H）
1st byte
Start bit ( AAH )
2nd byte
Address (0—31,0XFF)
3rd byte
Command（22H/23H）
4th byte
The Lowest byte of max voltage value
5th byte
The lower byte of max voltage value.
6th byte
The higher byte of max voltage value.
7th byte
The highest byte of max voltage value.
From 8th to 25th byte
System reserve.
26th byte
Sum code.
Represent a voltage upper limit value by 4 bytes of Hex. Lower bytes are in the front location, higher
bytes are in the later location. 1 represent 1mV.For Example : The voltage upper limit is 16.000V，
the hex code is 0X00003E80，then the 4th byte is 0X80，5th byte is 0X3E，6th byte is 0X00，7TH
byte is 0X00.
4. Set / Read the max input current .（24H/25H）
1st byte
Start bit ( AAH )
2nd byte
Address(0—31,0XFF)
3rd byte
Command（24H/25H）
NOTE
NOTE

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4th byte
The Lowest byte of max current value
5th byte
The Lowest byte of max current value
6th byte
The higher byte of max current value
7th byte
The highest byte of max current value
From 8th to 25th byte
System reserve
26th bye
Sum code
Represent an current value by 4 bytes of Hex .Lower bytes are in the front location, higher
bytes are in the later location.1 represent 0.1mA,If setting upper limit is 3.0000A，the hex code
is 0X00007530，then the 4th byte is 0X30，5th is 0X75，6th is 0X00，7th is 0X00。
5. Set / Read max input power（26H/27H）
1st byte
Start bit ( AAH )
2nd byte
Address (0—0XFE)
3rd byte
Command（26H/27H）
4th byte
The lowest byte of max power value.
5th byte
The lower byte of max power value
6th byte
The higher byte of max power value.
7th byte
The highest byte of max power value.
From 8th to 25th byte
System reserve
26th byte
Sum code
Represent power value by 4 bytes of Hex. Lower bytes are in the
Front location, higher bytes are in the later location. 1 represents 1mW. If setting upper value is
200.000W，the hex code is 0X00030d40，then the 4th byte is
0X40，5th is 0X0d，6th is 0X03，7th is 0X00.
6. Select / Read operation mode(CC/CV/CW/CR) of electronic load.（28H/29H）
1st byte
Start bit ( AAH )
2nd byte
Address (0—31,0XFF)
3rd byte
Command（28H/29H）
4th byte
Mode（0 is CC mode, 1 is CV mode , 2 is CW mode , 3 is CR mode ）
From 5th to 25th byte
System reserve
26th byte
Sum code
7. Set / Read current value of CC mode（2AH/2BH）
1st byte
Start bit ( AAH )
2nd byte
Address (0—31,0XFF)
3rd byte
Command （2AH/2BH）
4th byte
The lowest byte of current value
5th byte
The lower byte of current value.
NOTE
NOTE

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6th byte
The higher byte of current value.
7th byte
The highest byte of current value.
From 8th To 25th byte
System reserve
27th byte
Sum code
Represent current by 4 bytes of Hex. Lower bytes are in the front location, higher bytes are in
the later location. For example: current is 3.0000A，Hex code is 0X00007530，NO. 4 bye is
0X30，NO. 5 bye is 0X75，NO. 6 bye is 0X00，NO. 7 bye is 0X00。
8. Set / Read voltage value of CV mode.（2CH/2DH）
1st byte
Start bit ( AAH )
2nd byte
Address (0—31,0XFF)
3rd byte
Command（2CH/2DH）
4th byte
The lowest byte of voltage value.
5th byte
The lower byte of voltage value.
6th byte
The higher byte of voltage value.
7th byte
The highest byte of voltage value.
From 8th to 25th byte
System reserve
26th byte
Sum code
Represent voltage by 4 bytes of Hex. Lower bytes are in the front location, higher bytes are in
the later location. For example :voltage is 16.000V，Hex code is 0X00003EB0，4th byte 0XB0，
5TH byte is 0X3E，6th byte is 0X00，7th bytes 0X00。
9. Set / Read watt value of CW mode（2EH/2FH）
1st byte
Start bit ( AAH )
2nd byte
Address (0—31,0XFF)
3rd byte
Command（2EH/2FH）
4th byte
The lowest byte of max power value
5th byte
The lower byte of max power value
6th byte
The higher byte of max power value
7th byte
The highest byte of max power value
8th to 25th byte
System reserve
26th byte
Sum code
NOTE
NOTE
NOTE

16
Represent power by 4 bytes of Hex. Lower bytes are in the front location, higher bytes are in
the later location. For example :power is 200.000W，Hex is 0X00030d40，4th byte is 0X40，
5th byte is 0X0d，6th byte is 0X03，7th byte is 0X00。
10. Set / Read resistance value CR mode（30H/31H）
1st byte
Start bit ( AAH )
2nd byte
Address (0—31,0XFF)
3rd byte
Command（30H/31H）
4th byte
The lowest byte of resistance value.
5th byte
The lower byte of resistance value.
6th byte
The higher byte of resistance value.
7th byte
The highest byte of resistance value.
8th to 25th byte
System reserve
26th byte
Sum code
Represent resistance value by 4 bytes of Hex. Lower bytes are
in the front location, higher bytes are in the later location. If resistance value is 200.000R，Hex
code is 0X00030d40，4TH byte is 0X40，5TH byte is 0X0d，6th byte is 0X03，7th byte is 0X00。
11. Set / Read CC mode transient current and timer parameter. （32H/33H）
1st byte
Start bit ( AAH )
2nd byte
Address (0—31,0XFF)
3rd byte
Command（32H/33H）
From 4th byte to 7th byte
Setting value of current A (Lower bytes are in the front location, higher bytes
are in the later location.)
From 8th byte to 9th byte.
Time value of timer A ((Lower bytes are in the front location, higher bytes are in
the later location) (1 represent 0.1mS)
From 10th to 13th byte
Setting value of current B (Lower bytes are in the front location, higher bytes
are in the later location)
From 14th to 15th byte
Time value of timer B (Lower bytes are in the front location, higher bytes are in
the later location) (1 represent 0.1mS)
16th byte
Transition operation mode (0 is CONTINUES, 1 is PULSE, 2 is TOGGLED)
From 17th to 25th byte
System reserve
26th byte
Sum code
12. Set / Read CV transient voltage and timer parameter.（34H/35H）
1st byte
Start bit ( AAH )
2nd byte
Address (0—31,0XFF)
3rd byte
Command（34H/35H）
From 4th to 7th byte.
Setting value of voltage A (Lower bytes are in the front location, higher bytes
are in the later location)
From 8th to 9th byte.
Time value of timer A (Lower bytes are in the front location, higher bytes are in
the later location) (1represent 0.1mS)
NOTE

17
From 10th to 13th byte
Setting value of voltage B(Lower bytes are in the front location, higher bytes are
in the later location)
From 14th to 15th byte
Time value of timer B (Lower bytes are in the front location, higher bytes are in
the later location) (1represent 0.1mS)
16th byte
Transient operation mode (0 is CONTINUES,1 is PULSE,2 is TOGGLED)
From 17th to 25th byte
System reserve
26th byte
Sum code
13. Set /Read CW transient watt and timer parameter（36H/37H）
1st byte
Start bit ( AAH )
2nd byte
Address (0—31,0XFF)
3rd byte
Command（36H/37H）
From 4th to 7th byte
Setting value of power A (Lower bytes are in the front location, higher bytes are
in the later location)
From 8th to 9th byte
Time value of timer A (Lower bytes are in the front location, higher bytes are in
the later location) (1 represent 0.1mS)
From 10th to 13th byte
Setting value of power B(Lower bytes are in the front location, higher bytes are
in the later location)
From 14th to 15th byte
Time value of timer B (Lower bytes are in the front location, higher bytes are in
the later location) (1 represent 0.1mS)
16th byte
Transition operation mode (0 is CONTINUES,1 is PULSE,2 is TOGGLED)
From 17th to 25th byte
System reserve
26th byte
Sum code
14. Set / Read CR transient resistance and timer parameter（38H/39H）
1st byte
Start bit ( AAH )
2nd byte
Address (0—31,0XFF)
3rd byte
Command（38H/39H）
From 4th byte to 7th byte
Setting value of resistance A (Lower bytes are in the front location, higher bytes
are in the later location)
From 8th byte to 9th byte.
Time value of timer A (Lower bytes are in the front location, higher bytes are in
the later location) (1 represents 0.1mS)
From 10th byte to 13th byte
Setting value of resistance B (Lower bytes are in the front location, higher bytes
are in the later location)
From 14th byte to 15th byte
Time value of timer B (Lower bytes are in the front location, higher bytes are in
the later location) (1 represents 0.1mS)
16th byte
Transition operation mode (0 is CONTINUES,1 is PULSE,2 is TOGGLED)
17th byte to 25th byte
System reserve
26th byte
Sum code
15．Set /Read the list operation mode (CC)（3AH/3BH）
1st byte
Start bit ( AAH )
2nd byte
Address (0—31,0XFF)
3rd byte
Command（3AH/3BH）

18
4th byte
LIST operation mode（0 is CC mode）
From 5th to 25 byte
System reserve
26th byte
Sum code
16. Set / Read the list repeat mode. (3CH/3DH)
1st byte
Start bit ( AAH )
2nd byte
Address (0—31,0XFF)
3rd byte
Command（3CH/3DH）
4th byte
LIST repeat operation mode(0 is ONCE, 1 is REPEAT,65535 represents no limit)
From 5th to 25th byte
System reserve
26th byte
Sum code
17. Set / Read list step counts. (3EH/3FH)
1st byte
Start bit ( AAH )
2nd byte
Address (0—31,0XFF)
3rd byte
Command（3EH/3FH）
From 4th byte to 5th byte
LIST steps count
From 6th to 25th byte
System reserve
26th byte
Sum code
18. Set / Read one of the step’s current and time values. (40H/41H)
1st byte
Start bit ( AAH )
2nd byte
Address (0—31,0XFF)
3rd byte
Command（40H/41H）
From 4th byte to 5th byte
Appointed one step
From 6th to 9th byte
Current value of current step (Lower bytes are in the front location, higher bytes
are in the later location)
From 10th to 11th byte
Time value of current step (Lower bytes are in the front location, higher bytes are
in the later location) (1 represent 0.1mS)
From 12th to 25th byte
System reserve
26th byte
Sum code
19. Save / Recall list file in appointed area.. (4CH/4DH)
1st byte
Start bit ( AAH )
2nd byte
Address (0—31,0XFF)
3rd byte
Command（4CH/4DH）
4th byte
Storing area (1 ~ 7)
From 5th to 25th byte
System reserve
26th byte
Sum code
20. Setting / Reading timer value of FOR LOAD ON (50H/51H）
1st byte
Start bit ( AAH )
2nd byte
Address (0—31,0XFF)
3rd byte
Command（50H/51H）

19
4th byte
The lowest byte of time value in timer. (1 represent 1S)
5th byte
The highest byte of time value in timer.
From 8th to 25th byte
System reserve
26th byte
Sum code
Time unit in Timer is S, 1S is represented by 1.
21. Disable / Enable timer of FOR LOAD ON (52H);
Enquire timer state of FOR LOAD ON (53H)
1st byte
Start bit ( AAH )
2nd byte
Address (0—31,0XFF)
3rd byte
Command（52H/53H）
4th byte
Timer state (0:OFF,1:ON )
From 5th to 25th byte
System reserve
26th byte
Sum code
22. Set communication address (54H)
1st byte
Start bit ( AAH )
2nd byte
Address (0—0XFE)
3rd byte
Command （54H）
4th byte
New communication address (0~31)
From 5th to 25th byte
System reserve
26th byte
Sum code
23. Enable/Disable LOCAL control mode. (55H)
1st byte
Start bit ( AAH )
2nd byte
Address (0—31)
3rd byte
Command（55H）
4th byte
State of LOCAL button(0:disable,1:enable “)
From 5th to 25th byte
System reserve
26th byte
Sum code
24. Enable / Disable remote sense mode. (56H)
Enquire the state of remote sense mode. (57H)
1st byte
Start bit ( AAH )
2nd byte
Address (0—31,0XFF)
3rd byte
Command（56H/57H）
4th byte
Remote mode state (0:OFF,1:ON)
5th to 25th byte
System reserve
26th byte
Sum code
25. Set / Enquire trigger source. (58H/59H)
1st byte
Start bit ( AAH )
2nd byte
Address (0—31,0XFF)
3rd byte
Command （58H/59H）

20
4th byte
Trigger mode (0:Manual,1: External,2:Bus,3:Hold)
From 5th to 25th byte
System reserve
26th byte
Sum code
26. Send a trigger signal to trigging the electronic load. (5AH)
1st byte
Start bit ( AAH )
2nd byte
Address (0—31,0XFF)
3rd byte
Command（5AH）
From 4th to 25th byte
System reserve
26th byte
Sum code
27. Saving / Recall user’s setting value in appointed memory area for recall.
(5BH/5CH)
1st byte
Start bit ( AAH )
2nd byte
Address (0—31,0XFF)
3rd byte
Command（5BH/5CH）
4th byte
Storing area
From 5th to 25th byte
System reserve
26th byte
Sum code
28. Selecting / Getting FIXED/SHORT/TRAN/LIST/ BATTERY function mode.
(5DH/5EH)
1st byte
Start bit ( AAH )
2nd byte
Address (0—31,0XFF)
3rd byte
Command（5DH/5EH）
4th byte
Work mode (0:FIXED,1:SHORT, 2:TRANSITION,3:LIST,4: BATTERY)
From 5th to 25th byte
System reserve
26th byte
Sum code
29. Read input voltage, current, power and relative state. (5FH)
1st byte
Start bit ( AAH )
2nd byte
Address (0—31,0XFF)
3rd byte
Command （5FH）
From 4th to 7th byte
Actual input voltage value (Lower bytes are in the front location, higher bytes are
in the later location)
From 8th to 11th byte
Actual input current value (Lower bytes are in the front location, higher bytes are
in the later location)
From 12th to 15th byte
Actual input power value (Lower bytes are in the front location, higher bytes are
in the later location)
16th byte
Operation state register
From 17th to 18th byte
Demand state register
From 19th to 25th byte
System reserve
26th byte
Sum code