Limitation of Warranty .........................................................................................................
2
Quick Reference
About your safety
Pease review the following safety precautions before operating our equipment.
General information
The following safety precautions should be observed before using this product and any
associated instrumentations. Although some instruments and accessories would be
used with non-hazardous voltages, there are situations where hazardous conditions
may be present.
This product is intended for use by qualified personnel who recognize shock hazards
and are familiar with the safety precautions required to avoid possible injury. Read and
follow all installation, operation, and maintenance information carefully before using the
product. Refer to this manual for complete product specifications.
If the product is used in a manner not specified, the protection provided by the product
may be impaired.
Before performing any maintenance, disconnect the line cord and all test cables.
Protection from electric shock
Operators of this instrument must be protected from electric shock at all times. The
responsible body must ensure that operators are prevented access and/or insulated
from every connection point. In some cases, connections must be exposed to potential
human contact. Product operators in these circumstances must be trained to protect
themselves from the risk of electric shock. If the circuit is capable of operating at or
above 1000 volts, no conductive part of the circuit may be exposed.
Definition of users
Responsible body is the individual or group responsible for the use and maintenance of
equipment is operated within its specifications and operating limits, and for ensuring
that operators are adequately trained.
Operators use the product for its intended function. They must be trained in electrical
safety procedures and proper use of the instrument. They must be protected from
electric shock and contact with hazardous live circuits.
Service is only to be performed by qualified service personnel.
Safety symbols and terms
Connect it to safety earth ground using the wire recommended in the user
manual.
The symbol on an instrument indicates that the user should refer to the
operating instructions located in the manual.
High voltage danger
3
Certification and Warranty
Certification
We certify that this product met its published specifications at time of shipment from the
factory.
Introduction
The 1785B - 1788 Series power supplies are high performance single-output
programmable DC power supplies with communication interface. The combination of
bench-top and system features in these power supplies provides versatile solutions for
your design and test requirements.
Convenient bench-top features:
• Nice appearance, small-size and light weight
• VFD display
• Soft Rubber numeric keypad
• Adjustable & constant voltage outputs
• Adjustable & constant current outputs
• Output on/off
• High accuracy and high resolution
• Excellent load and line regulation
• Low ripple and noise
• Limit voltage protection
• Over current/temperature protection
• Sixteen operating states storage
• May be used in series or parallel modes with additional power supplies
4
The Front Panel at a Glance
1
1
2
2
4
3
3
4
5
5
? 10 digits VFD display
? Status information for operating mode and working status
? Power switch
? Number keys
? Function keys
? UP/DOWN and ENTER key
? Output terminals
5
76
76
V-set I-set Save
Menu Recall
Out on/off
Function keys description
Set the output voltage value
Set the current value
Save the present settings to a specified register location(1~16)
Recall a saved settings from location ‘‘1’’through ‘‘16’
Menu function to set related parameters of the power supply
Output ON/OFF, to enable/disable the output
Menu description
>MAX VOLT
Set the maximum output voltage value
>INIT OUTInitiate the output state to ON or not>INIT VOLInitiate the output voltage to 0 volt or not
>KEY SOUN Switch On/Off the buzzer sound when you press
any key
>BAUDRATE Set the communication baud rate
>ADDRESSSet the communication address
>KEY LOCKSet the password for function keys
>EXITExit
Display annunciators
6
ON Output ON
ON Output ON
Oh Overheat protection state
Oh Overheat protection state
CVThe power supply is in constant
CVThe power supply is in constant
voltage mode.
voltage mode.
CCThe power supply is in constant
CCThe power supply is in constant
current mode.
current mode.
Unreg The output of the power supply
Unreg The output of the power supply
is unregulated (neither CV nor CC)
is unregulated (neither CV nor CC)
The Rear Panel at a Glance
Link The power supply is in communication
Link The power supply is in communication
mode
mode
RmtThe power supply is in remote mode
RmtThe power supply is in remote mode
CalThe power supply is in calibration mode
CalThe power supply is in calibration mode
The function keys are locked by password
The function keys are locked by password
The rotate speed of cooling fan
One of the first things you will want to do with your power supply is to become acquainted with the front
panel. The exercises in this chapter prepare the power supply for use and help you get familiar with
some of its front-panel operations.
This chapter is intended for both the experienced and the inexperienced user because it calls attention
to certain checks that should be made prior to operation.
1.1 Preliminary Checkout
The following steps help you verify that the power supply is ready for use.
1. Check the list of supplied items.
Verify that you have received the following items with your power supply. If anything is missing, contact
your nearest Sales Office.
? One power cord for your location
? This User’s Manual.
? Communication cable (optional)
2. Connect the power cord and turn on the power supply.
When you turn on the power supply, the front-panel display will light up briefly while the power supply
performs its power-on self-test. All the VFD annunciators will light up at once. To review the display with
all annunciators, you can check if there is any stroke loss on any annunciator. If there isn’t any response
when you power on the power supply, please see Section 1.5 on page 10 for some service information.
If the EEPROM was damaged or the latest operation data in EEPROM was lost, the VFD will display as
follows:
If the calibration data in EEPROM was lost, the VFD will display as follows:
the third conductor being the ground. The power supply is grounded only when the
power-line cord is plugged into an appropriate receptacle. Do not operate your power
supply without adequate cabinet ground connection.
: Your power supply is equipped with a 3-wire grounding type power cord;
8
Out
on/off
Out
on/off
Out
on/off
1.2 Output Checkout
The following procedures check to ensure that the power supply develops its rated outputs and properly
responds to operation from the front panel.
1.2.1 Voltage Output Checkout
The following steps verify basic voltage functions without load.
1. Turn on the power supply.
2. Enable the outputs.
Press key to let the ON annunciator and the CV annunciator turn on to light.
Notice: if the voltage value flash, then the power supply is in Set mode, ‘‘Set mode’’ means that the VFD
display shows the setting output voltage and current. Or the power supply is in Meter mode, ‘Meter
mode” means that the VFD display shows the actual output voltage and current.
3. Check that the front-panel voltmeter properly responds to number keys
Set some different voltage values, then wait till the Meter mode to check if the VFD displayed voltage
value is the same as the set voltage value, and to check if the VFD displayed current value is nearly
zero.
4. Ensure that the voltage can be adjusted from zero to the full rated value.
1.2.2 Current Output Checkout
The following steps check basic current functions with a short across the power supply’s output.
1. Turn on the power supply.
2. Disable the output
Press key to ensure that the output is disabled. The ON annunciator is turned off.
3. Connect a short across (+) and (-) output terminals with an insulated test lead.
Use a wire size sufficient to handle the maximum current.
4. Enable the output.
Press key to ensure that the output is enabled. The ON annunciator is turned on.
5. Adjust the voltage value to 1.0 volt.
Adjust the voltage to 1.0 volt to ensure the power supply is in CC operation mode. The CC annunciator
will turn on.
6. Adjust the current value.
Set some different voltage values, then wait till the Meter mode to check if the VFD displayed current
value is the same as the set voltage value, and to check if the VFD displayed voltage value is nearly
Warning: To satisfy safety requirements, load wires must be heavy enough not to
overheat when carrying the maximum short-circuit output current of the power
supply. If there is more than one load, then any pair of load wires must be capable of
safety carrying the full-rated current of the power supply.
9
zero.
7. Ensure that the current can be adjusted from zero to the full rated value.
8. Turn off the power supply and remove the short wire from the output terminals.
1.3 If the Power Supply Does Not Turn On
Use the following steps to help solve problems you might encounter when turning on the instrument. If
you need more help, refer to chapter 6 for instructions on returning the instrument to the supplier for
service.
1. Verify that there is AC power to the power supply.
First, verify that the power cord is firmly plugged into the power receptacle on the rear panel of the power
supply. You should also make sure that the power source you plugged the power supply into is
energized. Then, verify that the power supply is turned on.
2. Verify the power-line voltage setting.
The line voltage is set to the proper value for your country (110VAC or 220VAC. Change the voltage
setting if it’s not correct.
3. Verify that the correct power-line fuse is installed.
If the fuse was damaged, please see the table below to replace the fuse for your power supply.
Fuse Description
Fuse 2.5A T 250V for 220VAC
Fuse 5A T 250V for 110VAC
1.4 To Adjust the Carrying Handle
To adjust the position, grasp the handle by the sides and pull outward. Then, rotate the handle to the
desired position.
10
Bench-top viewing positions Carrying position
1.5 To Rack Mount the Instrument
You can mount the power supply in a standard 19-inch rack cabinet using the IT-E151rack mount kit.
Note: Remove the carrying handle and the two plastic ears before rack-mounting the instrument.
To remove the handle, grasp the handle by sides and pull outwards and rotate it to a special position to let
the arrow on the handle and the arrow on the plastic ears be in opposite directions, then pull the handle
outward. After removing the handle, you can use a screwdriver to remove the two plastic ears.
To rack mount a single instrument, order rack mount kit IT-E151
Side view of rack mounting a single instrument
11
Programmi
Resolution
Read
To rack mount two instruments side-by-side, order rack mount kit IT-E151, you
needn’t to use the front cover panel.
Dimension unit (mm)
2.1 Specifications
Parameter 1785B 1786B 1787B 1788
Output Ratings,
( 0 °C - 40 °C)
Load Regulation,
±(% of output+offset)
Voltage
Current
LVP
Voltage
Current
Chapter 2 Specifications
0 ~18V 0 ~32V 0 ~72V 0 ~32V
0 ~5A 0 ~3A 0~1.5A
0 ~19V 0 ~33V 0 ~73V 0 ~33V
<
0.01% + 3mV
Model 1788 = <
0.02% + 5mV
<
0.1% + 2mA
0~6A
<
Line Regulation,
±(% of output+offset)
ng
back Resolution
12
Voltage
Current
Voltage 10mV
Current
Voltage
Current
Model 1788 = 0.05% + 120mV(=20V)
0.1% + 3mV
<
0.1% + 2mA
10mA
0.05% + 15mV(<20V)
<
0.1% + 15mA
Programming
Accuracy, 12months
(
±
Readback
12months
Tem
C
Read
Y
@ 25 °C ± 5 °C)
(% of output+offset)
,
Voltage
Current
<0.05% + 10mV
<0.2%+10mA
Accuracy
,
(25 °C ± 5 °C)
±(% of output+offset)
Ripple
(20Hz ~20MHz)
perature
oefficient,
(0 °C ~ 40 °C)
±(% of output+offset)
back
emperature,
Coefficient,
±(% of output+offset)
Voltage
Current
Voltage
Current 5mArms
Voltage
Current
Voltage
Current
<0.05%+15mV(<20V),
<0.05%+120mV(=20V)
<0.1%+15mA
=1mVrms/3mVp-p
<0.02%+5mV
<0.1%+5mA
<0.02%+15mV(<20V),
<0.02%+120mV(=20V)
<0.1%+15mA
2.2 Supplemental Characteristics
State Storage Memory
Sixteen (16) user-configurable stored states
Recommended Calibration Interval
1 year
AC Input Ratings (selectable via switch on the rear panel)
Option OP1: 220VAC ± 10%, 47 to 63 Hz
Option OP2: 110 VAC ± 10%, 47 to 63 Hz
Maximum input power
350VA
Cooling
Fan cooled
Operating Temperature
32 to 104 °F (0 to 40 °C) for full rated output
Storage Temperature
-68 to 158 °F (-20 to 70 °C) for storage environment.
13
Environmental Conditions
Designed for indoor use in an installation category II, pollution degree 2 environment. Designed to
operate at maximum relative humidity of 95% and at altitudes of up to 2000 meters.
Weight
Type 1785B 1786B 1787B 1788
N.W
G.W
Dimensions WxHxD*
10” x 4.16” x 15” (255.7mm x 105.7mm x 382.7mm)
12.3Lbs.
5.6Kg
14Lbs.
6.4Kg
14.8Lbs.
6.7Kg
16.5Lbs.
7.5Kg
14.8Lbs.
6.7Kg
16.5Lbs.
7.5Kg
14.8Lbs.
6.7Kg
16.5Lbs.
7.5Kg
(Unit: mm)
14
Chapter 3 Front-panel Operation
Out
on/off
So far you have learned how to install your power supply and do quick start. During the quick start, you
were briefly introduced to operating from the front panel as you learned how to check basic voltage and
current functions. This chapter describes in detail the use of the front-panel keys and shows how they
are used to accomplish power supply operation.
This chapter is divided into the following sections:
• Front-Panel Operation Overview‚ on page 14
• Constant Voltage Operation‚ on page 15
• Constant Current Operation‚ on page 15
• Storing and Recalling Operating States‚ on page 15
• MENU operation, starting on page 16
3.1 Front-panel Operation Overview
The following section describes an overview of the front-panel keys before operating your power supply.
1. The power supply is shipped from the factory configured in the front-panel operation mode. At
power-on, the power supply is automatically set to operate in the front-panel operation mode. When in
this mode, the front panel keys can be used.
2. When the power supply is in remote operation mode, you cannot use the front-panel. A change
between front-panel and remote operation modes will not result in any change in the output
parameters. You can change the front-panel and remote operation modes by computer.
3. The power supply is in Meter mode when it is powered on, and the VFD will display the actual voltage
and current output value. And in this mode, if any non-functional key is pressed, the power supply will
changed to Set mode, and the VFD will display the adjusted voltage and current value. In Set mode,
the set voltage value will flash, you can press ? and ? keys to adjust the voltage value. In Set
mode, the power supply will turn back to Meter mode if there is no any key is pressed for 3 seconds.
4. The output of the power supply can be enabled or disabled from the front panel by pressing
key. When the output is on, the ON annunciator will turn on.
5. The VFD display shows the present operating status of the power supply with annunciators. For
example, the power supply is operating in CV mode, and then the CV annunciator will turn on. If, the
power supply is remotely controlled, the Rmt annunciator will also turn on, See ‘‘Display
Annunciators’’.
3.2 Constant Voltage Operation
The constant voltage range is from 0V to the maximum voltage value of each model. It is very easy for
you to set the constant voltage output. You have 2 solutions to set the constant voltage value.
Solution 1:
Step1. Power on the Power Supply
Step2. Press the ? and? keys to change the value
Solution 2:
Step1. Power on the IT68xx instrument
15
V-Set
Enter
Enter
Save
Recall
Enter
Menu
Enter
I-
Set
00
00
Note:
Step2. Press key.
Step3. Use the numeric keys to or ? and ? keys to change the voltage value.
Step4. Press to confirm the value
9
3.3 Constant Current Operation
The constant current output range is from 0A to the maximum current value of each type. It is very easy
for you to set the constant current output.
Step1. Power on the Power Supply
Step2. Press key
Step3. Use the numeric keys to or use ? and ? keys to change the current value
Step4. Press key to confirm the value
9
3.4 Saving and Recalling Operation
You can store up to 16 different output states in storage register locations (1 to 16). Each output state
includes Constant voltage value, Constant current value and Maximum output voltage value. When
shipped from factory, storage locations “1” through “16” are empty. You can recall the saved settings by
Recall function.
Step1. After you setting an output state (CV value, CC value and Maximum voltage), press key.
Step2.Use the numeric keys to or ? and ? keys to select the memory location (the range
is 1 to 16) which you want to store in.
Step3. Press to confirm the memory location.
Step4. Press key.
Step5. Use numeric keys to or ? and ? keys to select the states which you want to
recall.
Step6. Press key to confirm. Then the saved settings will come on.
9
9
1. If the function keys were locked by password, you need to enter the correct
password after you press function keys (V-set, I-set, Save, Recall and Menu), then
you can do the settings.
2. If you want to cancel a function operation (V-set, I-set, Save, Recall or Menu), just
press key to exit.
Esc
3.5 Menu Operation
nSet Maximum voltage(>MAX VOLT)
Please be well known that the Max voltage value should be in the range of each type of IT68xx
Power supply.
Step1. Press key.
16
Step2. Select >MAX VOLT by using? and ? key.
Enter
Enter
0
Step3. Press key.
Step4. Change the voltage value by using numeric keys to or ? and ? key.
Step5. Press key.
Note: After you setting the maximum voltage value, the output voltage setup should
be in the range from 0 volt to maximum voltage.The default maximum voltage is
the full voltage range of its model.
9
nInitiating the Output state(>INIT OUT)
This instruction can initiate the output state when the power supply is powered on. If you select ON,
the power supply will initiate the output to OFF state when the power supply is powered on. If you
select OFF, the output will remain the same state as last time you turned off the power supply
Note: Default selection is ON and the output state is always OFF state.
nInitiating the Output Voltage (>INIT VOLT)
This instruction can set the initial output voltage. If you select ON, the power supply will initiate the
output voltage to 0Volt when the power supply is powered on. If you select OFF, the output voltage
will remain as the same volts as the last time you turned off the power supply
Note: Default setting is ON and the output voltage is 0 volt.
nSetting the Key Sound(>KEY SOUND)
This instruction can switch on/off the buzzing sound when you press any key, If you select ON, the
buzzer will sound when any key was pressed. If you select OFF, the buzzer will not sound when the
keys were pressed.
Note: Default setting is ON; the buzzer will sound when you press any key.
nSetting the Baud Rate(>BAUDRATE)
This instruction can change the communication baud rate for the power supply, the baud rate
range is 4800, 9600, 19200 or 38400? Before the communication, you must make sure that there
is same baud rate between the power supply and the computer.
Note: Default baud rate is 4800.
17
Note:
nSetting Address (>ADDRESS)
This instruction can set the communication address for each power supply. The address range is
from 0 to 254. Before the communication, you must make sure that there is same address
between the power supply and the computer.
Note: Default address is 0. When the power supply receives a frame instruction from
computer, the LINK indicator will light on; it means that the power supply started
to communicate with computer. If the power supply hasn’t received the signal
from computer for 3 seconds, the LINK indicator will be turned off and it means
that the power supply can not communicate with computer.
nSetting password for function keys(>KEY LOCK)
This instruction can set a password (1 through 4 digits) to lock the function keys operation. After
setting the password, all the function keys on the front panel will be locked except the OUT on/off
key. You must enter the correct password to unlock them, then you can continue to do the function
key operation. If you don’t want to lock the function keys, please don’t press any number key when
you enter the >KEY LOCK instruction, just press ENTER key to unlock it.
unlocked. The start bit of your desired password shouldn’t be 0.
When shipped from factory, there is no password and function keys are
18
Chapter 4 Remote Operation Mode
Note:
The DB9 interface connector on the rear panel of the power supply can be transferred to RS-232
interface, the following information will tell you how to use the computer to control the output of the
power supply.
4.1 IT-E131 Communicati on cable
The DB9 interface connector on the rear panel of power supply is TTL voltage level; you can use
the communication cable (IT-E131) to connect the DB9 interface connector of the power supply
and the RS-232 interface connector of computer for the communication.
Computer side TTL? RS232 Cable (IT-E131) PS side
IT-E131 communication cable
Power
PC
PCLoad
COMPUTER
COMPUTER
IT-E131 ISOLATED
IT-E131 ISOLATED
IT
IT
COMMUNICATION CABLE
COMMUNICATION CABLE
859666668889942311
859666668889942311
RX
RX
TTL(5V)RS232ISOLATION
TTL(5V)RS232 ISOLATION
TX
TX
INSTRUMENT
INSTRUMENT
supply
It will not work if you connect the DB9 interface connector of the power
supply to the RS232 interface connector of computer directly by a standard
RS232 cable. Please use IT-E131 to connect them.
4.2 Communication setting
Before using the remote operation mode, please make sure that the baud rate and communication
address in power supply 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.
1. Address: the range is from 0 to 254, default setting is 0
2. Baud rate: 4800,9600,19200 and 38400 are selectable, default setting is 9600
3. Data bit: 8 bit
4. Stop bit: 1
5. Parity: None
PARITY = NONE
Start
Bit
8 Data Bits
Stop
Bit
19
4.3 Frame format
Note
When the power supply is in calibration mode, it is not allowed to change the output
Frame length is 26 bytes, the format is as follows:
Start Address Command 4-25 bytes are information content Check sum
Description:
1. Start bit is AAH, occupies a byte.
2. Address range is 0 to FE, occupies a byte.
3. Command occupies a byte.
a. 20H----Setting the remote control mode
b. 21H----Setting the output ON/OFF state
c. 22H----Setting the maximum output voltage
d. 23H----Setting the output voltage
e. 24H----Setting the output current
f. 25H----Setting the communication address
g. 26H----Reading the present current/voltage, maximum voltage, setup voltage/current and
operation states of the power supply.
h. 27H----Enter the calibration mode
i. 28H----Reading the calibration mode state
j. 29H----Calibrate voltage value.
k. 2AH----Sending the actual output voltage to calibration program.
l. 2BH----Calibrate current value.
m. 2CH----Sending the actual output current to calibration program.
n. 2DH----Save the calibration data to EEPROM.
o. 2EH----Setting calibration information.
p. 2FH----Reading calibration information.
q. 31H----Reading product’s model, series number and version information.
r. 32H----Restoring the factory default calibration data.
s. 37H----Enable the local key.
t. 12H----The return information of command operation in power supply.
: You must change the power supply to remote control mode firstly, then you can
control the power supply output by computer. The command for remote control is
20H?
If you want to calibrate the power supply, set the calibration information or want to
set the product serial number, you must set the calibration protection mode to OFF
state firstly, the command for calibration protection is 27H.
4. 4th to 25th bytes are information content
5. 26th byte is check sum, the sum of the former 25 bytes.
Note: You can not control the power supply from the front panel when
4th byte Operation mode(0 represent front panel operation mode, 1
5th to 25th byte System reserve
26th byte Check sum
Command ( 20H)
represent remote operation mode)
the power supply is in calibration mode.
2. Setting the output state ON/OFF (21H)
1st byte Start bit (AAH )
2nd byte Address(0~0XFE)
3rd byte Command (21H)
4th byte
5th to 25th byte System reserve
26th byte Check sum
Output state(0 is OFF, 1 is ON)
3. Setting the maximum output voltage (22H)
1st byte Start bit (AAH )
2nd byte Address(0~0XFE)
3rd byte Command (21H)
4th byte The lowest byte of voltage upper limit
5th byte The lower byte of voltage upper limit
6th byte The higher byte of voltage upper limit
7th byte The highest byte of voltage upper limit
8th to 25th byte System reserve
26th byte Check sum
We use 4 bytes of Hex number to represent a maximum voltage value. For
example the maximum voltage is 16.000V, the hex code of 16.000 is
0X00003EB0, so the 4th byte is 0XB0, 5th bye is 0X3E, 6th byte is 0X00, 7th byte
is 0X00.
4. Setting the output voltage (23H)
1st byte Start bit ( AAH )
2nd byte Address(0~0XFE)
3rd byte
4th byte The byte 0 of output voltage value
5th byte The byte 1 of output voltage value
6th byte The higher byte of output voltage value
Command( 23H)
21
7th byte The highest byte of output voltage value
Note:
Note:
8th to 25th byte System reserve
26th byte Check sum
We use 4 bytes of Hex number to represent an output voltage value. For
example the output voltage value is 16.000V and the hex code of 16.000 is
0X00003EB0, so the 4th byte is 0XB0, 5th byte is 0X3E, 6th byte is 0X00, 7th byte
is 0X00.
3rd byte
4th byte To set the low byte of current value
5th byte To set the high byte of current value
6th to 25th byte System reserve
26th byte Check sum
Command( 24H)
We use 2 bytes of Hex number to represent an output current value. For
example the output current value is 1.000A, the hex code of 1.000 is 0X03E8,
so the 4th byte is 0XE8, 5th bye is 0XE3.
6. Setting the communication address (25H)
1st byte Start bit ( AAH )
2nd byte The current address of power supply(0~0XFE)
3rd byte Command(25H)
4th byte The new address
5th to 25th byte System reserve
26th byte Check sum
7. Reading the present current/voltage, maximum voltage, setup
voltage/current and the states of power supply. (26H)
1st byte Start bit ( AAH )
2nd byte Address(0~0XFE)
3rd byte
4th byte Byte 0 of present output current value
5th byte Byte 1 of present output current value
6th byte Byte 0 of present output voltage value
7th byte Byte 1 of present output voltage
Command( 26H)
8th byte Byte 2 of present output voltage
9th byte Byte 3 of present output voltage
10th byte Power supply’s state
22
11th byte To set the low byte of current value
Note:
Note:
12th byte To set the high byte of current value
13th byte Byte 0 of the maximum voltage value
14th byte Byte 1 of the maximum voltage value
15th byte Byte 2 of the maximum voltage value
16th byte Byte 3 of the maximum voltage value
17th byte Byte 0 of output voltage value
18th byte Byte 1 of output voltage value
19th byte Byte 2 of output voltage value
20th byte Byte 3 of output voltage value
21st to 25th byte System reserve
26th byte Check sum
1. We use 4 bytes to represent the maximum voltage value as follows:
Byte 3 Byte 2 Byte1 Byte
0
2. We use 1 byte to represent power supply’s state. Each bit is defined as
follows:
From higher bit to lower bit
7 6 5 4 3 2 1 0
0 bit: The output state, 0 is OFF, 1 is ON.
1 bit: Over heat protection, 0 is normal, 1 is abnormal.
2? 3 bit: The output mode, 1 is CV mode, 2 is CC mode,3 is Unreg mode.
4? 5? 6 bit: The fan speed, 0 is stop, 5 is the maximum fan speed.
7 bit: Operation state, 0 is front panel operation mode, 1 is remote control
4th byte Calibrated voltage points(point 1-3)
5th to 25th byte System reserve
26th byte Check sum
To calibrate the 3 points of voltage sequentially.
11. Sending the present output voltage to calibration program (2AH)
1st byte Start bit (AAH)
2nd byte Address(0~0XFE)
3rd byte Command(2AH)
4th byte The byte 0 of present voltage value
5th byte The byte 1 of present voltage value
6th byte The byte 2 of present voltage value
7th byte The byte 3 of present voltage value
8th to 25th byte System reserve
26th byte Check sum
12.Calibrate the current value (2BH)
1st byte Start bit(AAH)
2nd byte Address(0-0XFE)
3rd byte Command(2BH)
4th byte Calibrated current points( point 1-2)
5th to 25th byte System reserve
26th byte Check sum
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Note: To calibrate the 2 points of the current value sequentially.
13. Sending the actual output current to calibration program (2CH)
4th byte Command checkout result
5th to 25th byte System reserve
26
26th byte Check sum
Note:
When the power supply receives a frame command, it will check the frame
command, if the check sum is correct, then it will return to 90H, if there is
any error on setting parameter or over parameter, then it will return to A0H, if
the command wasn’t executed, then it will return to B0H, if the command
isn’t effective, then it will return to C0H. Or otherwise, it will return to 80H.
Chapter 5 Calibration
We suggest you to calibrate the power supply yearly. We provide you a set of calibration software Power
Calibration (PC1785B_1788). It is very easy to calibrate the power supply by the calibration software.
Please make the following preparation before the calibration.
1. Please prepare a high accuracy multi-meter (the accuracy should be higher than the power supply).
Prepare to use the multi-meter to measure the output voltage and short circuit current of the
calibrated power supply.
2. Use IT-E131 communication cable to connect the DB9 interface connector of the power supply and
the RS232 interface connector of the computer.
3. Install the PC1785B_1788 calibration software on your computer, and start the software.
After doing the above preparation, then you can calibrate the power supply easily by the software step
by step. Please refer the following calibration process.
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5.1 Configuration
Start the PC1785B_1788 System, the windows is as follows:
Voltage
calibration
Current
calibration
The diagram of
connecting the multimeter to the calibrated
power supply
The diagram of
connecting the multimeter to the calibrated
power supply
Before the calibration, please click “Config” button to set the COM interface, address and baud rate. The
default Com port is COM, and the default baud rate is 9600. Please make sure that the baud rate and
address in the software and in power supply are the same.
5.2 Voltage calibration
Step 1: Prepare to use multi-meter to measure the output voltage, and connect the voltage meter to the
power supply according to the diagram in the above windows.
Step 2: Click “Linked” button.It will go into Calibration mode, the Rmt and Cal indicators will light up.
Step 3: Fill the first voltage valueyou measured from the multi-meter to the blank of “0.000V”, and
click “OK” button to confirm the value.
Step 4:Fill the second voltage valueyou measured from the multi-meter to the blank of “0.000V”, and
click “OK” button to confirm the value.
Step 5: Fill the third voltage value you measured from the multi-meter to the blank of “0.000V”, and
click “OK” button to confirm the value.
5.3 Current calibration
Step 1: Prepare to use multi-meter to measure the short circuit current, and connect the current meter to
the power supply according to the diagram in the above windows.
Step 2: Click “Linked” button, it will go into Calibration mode, the Rmt and Cal indicators will light up.
Step 3: Fill the first current value you measured from the multi-meter to the blank of “0.000A”, and click
“OK” button to confirm the value.
Step 4:Fill the second current valueyou measured from the multi-meter to the blank of “0.000A”, and
click “OK” button to confirm the value.
5.4 Finish calibrating
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When you measure the output voltage or short current by the multi-meter, please make
sure the value is correct. Otherwise it will cause the calibration failure and let the
output turbulence.
Please make sure that the maximum current of your multi-meter is higher than the
maximum current of the calibrated power supply, otherwise it would damage the
multi-meter.
5.4 Reset to the default calibration settings
In the calibration process, if there is any failure caused by the misreading the voltage value and current
value or any other reason, you can use the “Restore” to let the power supply return to the state before
calibrating.
Chapter 6 PV1785B_1788 Software
6.1 Introduction
Software PV1785B_1788 is control software for 1785B - 1788 series programmable power supplies. It
can work with all single-output power supply models. Please make sure that you purchased IT-E131
communication cable, and use IT-E131 to connect the power supply and computer before the
communicating. This software can accomplish all the functions of the power supply, such as setting
constant voltage, setting constant current, max voltage etc. Also you can make quickly settings or make
a program for the output voltage and current by the computer. In addition, PV1785B_1788 offer a
GO/NG test function for automatic factory testing .It brings you much convenient when you use the
power supply.
6.2 Installation
1. Requirements for the computer
Pentium III or Pentium IV processor-based personal computer
Windows 98/2000/XP or Windows NT4.0
2. Insert the CD-Rom which supplied with the instrument to the CD driver, and install the software step
by step according to the instructions. The software PV1785B_1788 and PC1785B_1788 will be
installed on your computer at the same time.
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6.3 Functions of PV1785B_1788
Start the software PV1785B_1788, the windows is as follows:
1
2
11
10
3
9
4
5
1
Configure the software operation environments.
Voltage chart, it can show you a chart of the voltage.
2
Current chart: it can show you a chart of the current.
3
To set the remote mode of power supply.
4
5
To set the output state ON/OFF.
To enable the local numeric key , it means that if you select “Enable” on this button, when the
6
power supply is under remote control mode, you can press numeric key to change the
control mode to front panel control mode.
Annunciators display.
7
Status bar, it can show you the power supply model, communication status and operation status.
8
To set current value, use the rotary knob to set the current value, the setup value and
9
measurement value will be displayed.
To make a program of voltage and current values for the power supply, or to set the output value
10
quickly.
11
Using the rotary knob to set the voltage value, the setup value and present value will be displayed
in the 2 indicators.
67
7
8
7
30
6.3.1Configure the system
The first step for communication is to configure the system, click Configure button , the
windows will display as follows:
1) Comm: to set the communication port, baud rate and
address.
2) Max voltage: to set a maximum voltage value in the
voltage range. For example, the voltage range of
IT6822 is 0~32V, then you can set a maximum voltage
at 24V.
3) Voltage step: to set the step size of Arrow key, page
up/down key, and Mouse-wheel. When you set the
value by clicking the knob, you can use the arrow keys
(?, ?, ?, ?), page up/down keys or mouse wheel to
adjust the value more slightly.
4) Reload last parameter: if you select it, then it will reload
Note: When you set the communication port, please make sure that the baud rate and
address of the computer are the same as the power supply.
the parameter settings of last time you close this
software.
6.3.2 Status bar
Status bar will give you the communication information. When the communication is successful, the
status bar will display as follows:
1. Model number, it will display the real part number of the field power supply which detected by the
computer. (6811/6812/6821/6822/6823……..).
2. Operation status (Operation correct/Check error), if Check error appears here, it means that there
is check error for your last operation command.
3. Communication status (Communication successful/Communication waiting), if Communication waiting appears here for more than 10 seconds, you need to check if there is any connection failure
between computer and power supply. After confirming the effective connection, then re-configure the
baud rate, address, comport etc, to make sure the same baud rate and address between power
supply and computer.
Communication status Operation status Model number
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6.3.3 Setting Voltage and current
indicator.
Voltage
Sweep
:
Hot Key
1. Setting voltage/current by rotary knob
Use mouse to click on the rotary knob and move mouse
to change the value. You also can use mouse wheel, or
Page Up/Down keys and arrow keys (?, ?, ?, ?) from
the keyboard to change the voltage value more slightly.
The setup value will be displayed on the second line
indicator.
Use mouse to click on the rotary knob and move mouse
to change the value. Also you can use mouse wheel,
Page Up/Down keys and arrow keys (?, ?, ?, ?) from
the keyboard to change the current value more slightly.
The setup value will be displayed on the second line
Note: Before you set the current and voltage value from the computer, please change the
operation mode to PC Control mode by pressing button.
2. Quickly setting
: Right-click each Hotkey Button, it will display as
“Modify Voltage/Current”. Click “Modify/Voltage/
Current”, it will display as follows, change the
voltage/current value as you desired, then click
OK button to confirm.
StartValue=0.0V, Stop Value=10V, Voltage Step=2V,
TimeDelay=2s. When you click the Run button, the voltage will
change according to the voltage sweep setup value, then you
can click Stop button to stop the voltage sweep. You can also
click the Chart button, the voltage chart will display as follows:
To set voltage sweep. For example,
32
Program:
ode includes Once, Repeat and Custom).
3. Program setting
Right-click on the Program area, the program
tools (Append a line, Insert a line, Delete a line, Delete
Select etc.) will appear on the window. Click the tools to
program the steps.
Double-click on each value to change them from key board
as you desired. Also you can change the time unit
(hour/minute/second) by clicking on “Sec”.
After programming, you can select a run mode for your
program. (Run m
Click “Run” button to send the program settings to the power
supply. The power supply’s output will respond to the
program.
Click “Stop” button to stop sending the program settings to
the power supply. The power supply state will return to the
state before the program running.
Click “Chart” to show the voltage and current chart of the
program.
You can do some analysis on the chart or print the chart.
The chart is as follows:
6.3.4. GO/NG Test Function
GO/NG is an auto test function, to test if the EUT
(equipment under test) can meet the specification. To use
this function, follow up the steps below:
1. Right-click on the window, the edit tools (Append a line,
Insert a line, Delete a line, Delete Select etc.) will
appear on the window. Use the edit tools to edit the test
steps.
2. To set the Voltage, Max Amps, Min Amps and Delay
time according to the specifications of the EUT.
3.Click the Run button to start the test. If the Real Amps of
all steps are in the range of Min Amps to Max Amps,
then the EUT will pass the test, the Pass window will
appear.
4. If there is a Real Amps beyond the range in any step,
the EUT will not pass the test.
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6.3.5 Save and Open
To save the program settings, quickly settings, voltage sweep settings and GO/NG
settings as PAR file.
To open the PAR file for reloading the program settings, quickly settings, voltage
sweep settings and GO/NG settings.
6.3.6 Present Voltage/Current Chart
Double click the voltage
chart, the voltage chart
will be enlarged and will
display as more details.
Double click the current
chart, the current chart will
be enlarged and will
display with more details.
6.3.7. Chart Description
The voltage and current chart can help you to analyze voltage and current changes more easily.
We take the voltage chart as the example to let you know how to use it. The chart window is as
follows:
34
Click here and
move to zoom
in/out axes or
scroll axes
To set the ring buffer size
To set the limit position
To set the Y-Axes Span
To set the X-Axes Span
Vertical marker
Horizontal marker
XY Value marker
Limit range between the minimum value and maximum value.
Scroll axes mode
Zoom in/out axes mode
Zoom out
Zoom in
Save the chart as a .BMP file.
Clear all data
Resume tracking
Auto scale
Print the chart
Zoom rectangle
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Limited One-Year Warranty
B&K Precision Corp. warrants to the original purchaser that its product and the component parts
thereof, will be free from defects in workmanship and materials for a period of one year from the
data of purchase.
B&K Precision Corp. will, without charge, repair or replace, at its’ option, defective product or
component parts. Returned product must be accompanied by proof of the purchase date in the
form a sales receipt.
To obtain warranty coverage in the U.S.A., this product must be registered by completing and
mailing the enclosed warranty card to B&K Precision Corp., 22820 Savi Ranch Parkway, Yorba
Linda, CA 92887 within fifteen (15) days from proof of purchase.
Exclusions: This warranty does not apply in the event of misuse or abuse of the product or as a result of
unauthorized alternations or repairs. It is void if the serial number is alternated, defaced or removed.
B&K Precision Corp. shall not be liable for any consequential damages, including without limitation
damages resulting from loss of use. Some states do not allow limitation of incidental or
consequential damages, so the above limitation or exclusion may not apply to you.
This warranty gives you specific rights and you may have other rights, which vary from
state-to-state.
Model Number: ______________ Date Purchased: __________
22820 Savi Ranch Parkway
Yorba Linda, CA 92887
714.921.9095
714.921.6422 Facsimile
36
Service Information
Warranty Service: Please return the product in the original packaging with proof of purchase to the
below address. Clearly state in writing the performance problem and return any leads, connectors
and accessories that you are using with the device.
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Clearly state in writing the performance problem and return any leads, connectors and accessories
that you are using with the device. Customers not on open account must include payment in the
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charge includes return shipping to locations in North America. For overnight shipments and
non-North America shipping fees contact B&K Precision Corp..