USA Measurements US-731S User manual

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US-731S WEIGHING INDICATOR
Operating Manual - Version 1.00

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Contents
Chapter 1 Introduction ..................................................................................... 3
Chapter 2 Specifications ................................................................................... 4
Chapter 3 Function diagram ............................................................................ 5
Chapter 4 Operation ......................................................................................... 7
4.1 keys ......................................................................................................... 7
4.2 Battery using .......................................................................................... 7
4.3 Basic operation ...................................................................................... 8
4.4 Parameters set ....................................................................................... 9
4.5 Calibration ........................................................................................... 11
4.6 Error code ............................................................................................ 11
Chapter 5 Communication Interface ............................................................. 12
5.1 RS232 serial port communication ...................................................... 12
5.2 Load cell connection ( 5pin Air plug) ................................................ 13
Chapter 6 Maintenance and precautions ...................................................... 14

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Chapter 1 Introduction
US-731S weighing indicator comes standard with weighing functions
to total the weight, change from lb or kg, and our animal weighing
mode. The US-731S will include our RS232 port for connecting to the
computer or printer. The low power model will cut off the power when
the battery is too low in order to protect the indicator. US-731S can
power up to four 350 ohm load cells to be used with a variety of
different scales. Finally, the US-731S indicator includes our sleep
function to help save power on the battery when the indicator is not in
use.

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Chapter 2 Specifications
Parameter Settings:
1 Model: US-731S
2 Accuracy: Grade III, n=3000
3 Display: 6 button bright led, one inch digita
4 A/D conversion parameters: sigma delta, 24bit, 10 times / sec
5 Input span: -16mV ~ 18mV
6 Keyboard: 6 thin film button
7 Supply: DC12V, 1A
8 Battery: 7.4V/4AH lithium battery
9 Battery working time: 40 hours (continuous use)
10 Communication interface: RS232 output
11 Working / storage temperature: 0 ~ 40℃ / -25℃ ~ 55℃
12 Weight: Can be used in lb or kg

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Chapter 3 Function diagram
(figure 3-1-1 ) Function diagram of front view
Power on/off
Zero
Tare
Function
Clear
Enter

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(figure 3-1-2 ) Function diagram of back view
Battery cover
Load cell
COM
RS232/485
Power

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Chapter 4 Operation
4.1 keys
key
function
Second function
Set function
Long press enter function
increase,move
right
Short press
increase
Clear
quit
quit
Enter
Tare
increase
increase
Zero
Power on/off
4.2 Battery using
The battery supply the indicator , and can work continuously for about 50
hours.
When low power, the light indicating low power will turn on, it is time
to charge, if not, the indicator will be powered off in 30 minutes. This time
you must charge it, or it can not work.
When charging, no need to power on the indicator.
When working using battery, please charge it when the low power indicating
light on, or the indicator will power off after warning once low power to protect
the battery. If need to work continually, must charge it.
First time to use ,please charge it to be full.
The light is red when charging, turn green when the battery is full, no

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need to charge continually to use.
If not use the indicator for a long time, please charge it every three
months.
If the battery is found to be full of dissatisfaction or can only be used
for a short time even if full of power after being used for a long time, please
replace the new battery according to the specification of the battery.
4.3 Basic operation
4.3.1 Power on/off
Press the power on/off key to power on.
The indicator will self-checking after power on, and enter the state of
weighing.it can zero auto, and the zero light will be lighten.
If the indicator power off auto after flashing display “Lo bat”,please
charge it or plug in the supply to use continually.
Press the power on/off key to power off.
4.3.2 Over capacity warning
Please do not put the weight more than the max capacity on the scale, when
display“--O L--” and beep, please take down the weight immediately to
avoid the load cell damaged.
4.3.3 Zero Scale
When display non zero but no goods on the scale platform, press the key
zero to zero the scale.
This function is not valid when the display weight is outside of the zero
range.（default 2%）。
4.3.4 Tare Scale
Put on the weight, when stable light is lighten, press the key “T” to
tare the scale, the net light is lighten, put on the weight continually,
display net weight.
Press the key “C” to Clear the tare weight.

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4.4 Parameters set
In weighing state , long press F key to turn to function setting
state, press T key to page up or page down, press to confirm,
here start to set parameter, displaying first function P0. PWR
Press T key to page up to select other function, and press
to confirm the selected function. Here set the value using the T key,
press to confirm the value, press C key to quit. Such as: when
display “P0. PWR”,press , here display“SLEEP”,press
to confirm，and press T to select， press C to quit, the indicator
turns to weighing state.

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Function menu
P0.PWR
（power）
SLEEP
SLP ON
SLP OFF
BEEP
BP OFF
（OFF Alarm）default
BP OK
（OK Alarm）
BP NG
（Not OK Alarm）
BP LO
（Low Alarm）
BP HI
（High Alarm）
P1.UNIT
UT KG
UT G
UT LB
P2.CHK（check）
HI(
High
)
LOW
（Low）
P3.UART(commu
nication)
B 9600(
baud rate
)
FORM 1
FORM 2
FORM 3
P4.SDLY(commu
nication delay)
SD05(
delay time
)
P5.TEECH(weighi
ng parameters )
password
P1 REF
A2N 0(zero trace range)
0-AUTO(auto zero range)
0-RANG(push button zero range)
FILTER
P2.CAL
SIG RA(
single
)
DUA IN(
double
)
DECI(
decimal
)
INC (increment)
CAP(
capacity
)
CAL(
calibration
)
P3.PRO
TRI()
COUNT(
ADC code
)
RESET(Load Factory Default Values)

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4.5 Calibration
When the indicator is self-checking state, press
,
display
PIN, press C, ,T one by one, display UNLOAD, here make sure the
scale platform is clean, and the stable light is lighten, press
to confirm, here display the value of testing weight, press F to
change current flashing position, press T to increase value, change
the value to target testing weight, and then press to confirm,
here display LOAD, put on the testing weight, when the stable light
is lighten, press to confirm. Calibration completely, the
indicator displays the testing weight.
4.6 Error code
Error code
Description
resolution
- -O L- -
Over capacity
Take down the weight from scale platform
If there is still a problem please contact the
dealer or agent.
Err 4
Outside zero
range
Auto zero function is open or pushing button
zero, the weight is outside the zero range.
Take down the weight and try again.
Press T to tare scale to display zero.
Err 6
A/D Convert
outside
A/D converter value is outside the normal
range.
If over capacity, please take down the weight.
The load cell or circuit board may be damaged.

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Chapter 5 Communication Interface
5.1 RS232 serial port communication
Interface definition
DB9 male head interface output RS232 signal
Pin3 is TXD
，
Pin5 is GND
，
as follows shown.
Connecting to the computer
AW1 indicator DB9
male
Computer DB9
male
Description
Pin 3
（
TXD
）
Pin 2
（
RXD
）
Data Line
：
indicator send ,computer
receive
Pin 5
（
GND
）
Pin 5
（
GND
）
Ground
Pin 2
（
NC
）
Pin 3
（
TXD
）
No need to connect
Communication format
Each frame data is 9 bytes, the specific format as the table shown.
Bytes position
Definition
1
= start
2
Weight data(Display weight with decimal point
）
low char
：
Weight data
：
：
Weight data
：
8
Weight data high char
9
0 or - symbol
Such as: display weight is 3.000, then send data is
：
＝
000.3000
＝
000.3000
＝
000.3000
＝
000.3000
Such as: display weight is -1.00, then send data is
：
＝
00.1000
－＝
00.1000
－＝
00.1000
－＝
00.1000
－

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5.2 Load cell connection ( 5pin Air plug)
EXC+
SEN+
SEN-
EX C-
SIG+
S I G-
SHIELD
5
5
3
2
4
4
1
LOAD CELL

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Chapter 6 Maintenance and precautions
1 In order to ensure the indicator display clear and using for a long time, it should not be
placed in direct sunlight to use, should be placed relatively flat.
2 Should not be placed in the dust and severe vibration to use, to avoid the wet environment,
should be far away from strong corrosive objects and flammable and explosive materials.
▲！
Do not use in flammable gas or flammable vapor; should not be used in pressure vessel
canned system.
▲！
In areas with frequent lightning, reliable lightning protection must be installed to ensure the
safety of operating personnel.
To prevent the indicator and the corres po nd ing equipment damaged f rom l ig ht ni ng .
▲！
Signal source and indicator are static electricity sensitive equipment, taking effective
measures to prevent static electricity is necessary, The operation of electric welding or other strong
electric field is strictly prohibited on the measuring device; in the thunderstorm season, must
implement the reliable lightning protection measures to protect the signal source and indicator, to
ensure the safety of the operator's personal safety and weighing equipment and related equipment
safe operation.
3 The indicator and the battery do not have the waterproof ability, so pour water is forbidden.
4 It is strictly prohibited to use strong solvents (such as benzene, nitro oil) washing machine
shell.
5 A liquid or other conductive particle is not allowed to be injected into the indicator or the
wireless terminal box to prevent instrument damage and shock.
6 Before connecting the indicator and the external equipment, must cut off the power supply
of indicator and the corresponding equipment.
7 External interfaces shall be strictly used with the methods in the manual, and shall not be
changed without authorization. If there a problem, should immediately cut off the power, and
send it to professional maintenance person to prevent greater damage.
8 Advice to customers: should test and acceptance the indicator before using. We are only
responsible for the quality of the indicator itself, not responsible for the weighing system
problems.
9 The battery is easy to consume, does not belong to the scope of three packs.
▲！
In order to prolong the life of battery, it is necessary to charge the battery fully before using.

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If the indicator is not used for a long time, the battery must be charged every 3 months, 8-10 hours
once.
▲！
Should be careful when handling or installation, avoid strong vibration, shock or impact, to
prevent the battery short circuit to damage itself.
10 The indicator and wireless junction box have one year warranty, under normal conditions,
the problem not caused by human is the scope of the warranty, please send the product and
the warranty card (accord with number) to the special maintenance point or supplier. the
indicator and wireless junction box are done maintenance for lifelong. The indicator is not
allowed to open, otherwise no warranty.