Cardinal 748 User manual

748
WEIGHT INDICATING INSTRUMENT
TECHNICAL/OPERATION MANUAL
P.O. Box 151
Webb City, MO 64870
PHONE: [phone]
FAX: [phone] Printed in USA
8539-M041-O1 Rev H
11/98
Cardinal
Cardinal Scale Manufacturing Co.

1
SPECIFICATIONS
Power Requirements......115 VAC 60 Hz @ 0.07A (optional 230 VAC 50/60 Hz @ 0.03A) powering
12-18 VDC, 300-800 mA, wall plug-in UL/CSA listed power supply.
Enclosure Size ...............Desk Top: 11.3"W x 6.5"H x 3"D
NEMA 4X: 13.5"W x 8.6"H x 4.6"D
Operating Environment ..Temperature: 14˚ to 104˚ F or -10˚ to +40˚ C.
Humidity: 90% non-condensing (maximum).
Display............................Standard: 6-digit, 1" high, 7-segment LCD with 30 element bar graph
display. Optional: 6-digit, 0.8" high, 7-segment LED with 30 element bar
graph display.
Sensitivity .......................0.45 uV/division (0-3.3 mV/V input), class III.
Signal Input Range.........1.0 mV min. to 50 mV max. (including dead load boost).
Transducer Excitation.....8.0 volts VDC (12 VDC optional).
Number of Load Cells ....14 each, 350 OHM cells maximum.
Load Cell Cable Length..150 feet maximum. Consult factory for other requirements.
30 feet maximum without sense lines.
Resolution ......................1 part in 20,000 displayed. 1 part in 100,000 internal.
Capacities ......................1,000 to 10,000 divisions commercial. Up to 20,000 divisions
non-commercial.
Tare Capacity ................. 5 digits maximum.
Division Value.................1 to 9 x 10, 1, 0.1, 0.01, 0.001 and 0.0001.
Sample Rate ..................1 to 12 samples per second selectable.
Auto Zero Range............ 0.5 or 1 through 9 divisions.
Weighing Units ............... Pounds only, kilograms only, pounds/kilograms, tons only, or metric tons
only.
Keyboard........................ Membrane type with 27 color-coded keys.
Standard Features:
• Year 2000 compliant Time and Date with selectable date format (mm/dd/yy or dd/mm/yy).
• Six (6) digits of numeric identification.
• Up to eight (8) independent preset weight comparators with logic-level outputs and status
display.
• Keyboard or push button tare function.
• Gross, tare, net conversion.
• Programmable bar graph operation displays weight or preset weight comparator status.
• Test key performs display test and internal tests.
• Truck storage for 200 trucks, 24 bit, 16,777,216 maximum accumulator capacity.
• RS232/20mA printer port with selectable baud rate for printers.
• Bi-directional RS232/20mA interface with selectable baud rate can be used to control indicator
remotely.
• Auto shut-off feature turns indicator off after period of non-use.
• Automatic sleep mode turns display off when scale is not in use and automatically resumes
operation with the application of weight.
• Dual ranging feature with selectable parameters.
• Programmable print format.
• Consecutive number printing.
Optional Features:
• Relay output for connection of peripherals to be controlled by preset weight comparators.
• Optional I/O board includes:
Analog output with 0-10 VDC and 4-20 MA output.
BCD output with status lines.
Eight (8) optically-isolated programmable inputs.

2
INSTALLATION
AUTO-ON
AUTO-ON jumper J7, when connected, will
cause the indicator to power on automatically
whenever power is applied to the power input
connector.If power is lost momentarily and
then reapplied, the indicator will turn on
without pressing the ON key. See figure no.11
for location.
DOMESTIC/INTERNATIONAL JUMPER (J12
DOM/INT)
Remove the jumper to comly with OIML
requirements.The 748 will perform the
following functions: 1. A “lamp test” will be
performed on power-up.
2. The date format will be day/month/year.
3. The printout of keyboard tare will be
designated as “PT.”
LOAD CELL CONNECTIONSWITH OVER
30 FEET OF CABLE
For installations with over 30 feet of cable
between the indicator and the load cells,
sense wires should be used.The sense wires
must be connected between the +SENS, -SENS terminals on the indicator and the +EXCITATION, -
EXCITATION wires of the load cells or the +SENS, -SENS terminals of the load cell trim board or
the section seal trim board. For the indicator to use the sense wires, the +SENS jumper J1 and the -
SENS jumper J3 must be open (see figure no. 11).
The Model 748 Weight Indicating Instrument is available in either stainless steel desktop enclosure
or a NEMA 4X stainless steel wall-mount enclosure.Determine which enclosure version you have
and refer to the appropriate section for installation and interconnection.
DESKTOP ENCLOSURE
The 748 desktop enclosure may be mounted on a desktop or other smooth, flat, horizontal surface
or may be mounted on a wall.Refer to figure no. 1 for a layout of wall-mounting bolts.Regardless of
the manner in which the instrument is installed, the location should be free from temperature
extremes and water. It should be a location where the display is easily viewed and the keyboard is
within easy reach of the operator. If wall mounted, make certain the structure and mounting bolts
are of sufficient strength to retain the 748.
NO!
KEEP THE AREA AROUND THE SCALE
CLEAR
TO PROVIDE ADEQUATE AIR CIRCULATION
PROVIDE ADEQUATE
PROTECTION TO
MINIMIZE LIGHTNING
DAMAGE
NO!
?
PROVIDE GOOD, SAFE GROUND
AND CLEAN AC POWER
DON'T EXPOSE
TO DIRECT SUNLIGHT
NO!
-110˚
32˚-
DON'T EXPOSE TO
TEMPERATURE EXTREMES
NO!
DON'T PLACE IN FRONT OF
HEATING/COOLING VENTS
CAUTION! When in parallel runs, locate
Load Cell cables a minimum of 24" away
from all AC wiring.
figure no. 1 - wall
mounting bolt layout
8.000"
Clearance for
#10 size screw .203"
.375"

3
All of the terminations to
the desktop enclosure
version of the 748 are
made on the rear panel
via “D”style connectors.
See figure no. 2 to see
the identification of each
of these connectors.
LOAD CELL CONNECTION
CAUTION! Disconnect any external load cell power supply before connecting load cells to
the instrument. Failure to do so will result in permanent damage to the instrument.
The load cell cable is terminated via a 9-pin connector on the rear panel. Figure no. 3 shows the pin
identification for the connector. Make certain that the pins are correctly identified before soldering a
wire to them.NOTE!! If you use sense leads in your load cell installation (as in motor truck scales),
jumpers J1 and J3, located on the PC board, should be disconnected or placed on one pin only. If
you do not use sense leads, jumpers J1 and J3 must be installed to connect the sense leads to the
excitation (refer to figure no.11). Make certain that the connector retaining screws are used to hold
the connector securely to the rear panel.
REMOTE INPUT
PWC OUTPUT LOAD CELL
BCD OUTPUT ANALOG OUTPUT
PRINTER OUTPUT SERIAL I/O
18 VCD
0.8 A
figure no. 2 - connector identification
PIN 5 PIN 1
PIN 9 PIN 6
MATING CONNECTOR
CONNECTOR ................DE-9P
CONNECTOR SHELL....DE-24657
SCREW LOCK ...............DE-20419 figure no. 3 - load cell
connection
Load Cell
Standard Printer Output Connector
20mA Current Loop Pin Definitions
(indicator has active end)
20mA 10 RX
GND 11
Internal
Circuitry Printer Conn. Peripheral Device Passive End
PIN NUMBER FUNCTION
1.................+ EXCITATION
9.................+ SENSE
7.................+SIGNAL
2.................- SIGNAL
4.................- SENSE
6.................- EXCITATION
5.................SHIELD
Standard "Printer Connector RS-232C Pin Definitions:
TXD 2
*CTS 5
SIG GND 7
Part No. Vendor Part No.
6610-2047 DB-25P CONNECTOR
6610-2218 BACK SHELL
Mating Connector
PIN 13
PIN 14
PIN 25
PIN 1
PRINTER OUTPUT CONNECTION
If a printer is used, it may be connected to the printer output connector located on the rear panel.
Figure no. 4 shows the connections for both RS232 compatible data and 20 mA current loop
interfaces for the printer output.
figure no. 4 - printer output connection
NOTE! *RS232 CTS handshake input is enabled during calibration or setup review.

4
PIN 13
PIN 14
PIN 25
PIN 1
PRESETWEIGHT COMPARATOR LOGIC LEVEL OUTPUT
To automatically switch AC powered external devices at up to eight preset weight values, connect
the RB4 or RB8 external relay junction box to the PWC OUTPUT connector.When the displayed
weight is equal to or greater than the preset weight (see KEYPAD FUNCTIONS: PRESET key), the
PWC output changes from 5 volts dc to 0 volts dc or from 0 volts dc to 5 volts dc (see PRESET
WEIGHT COMPARATORS, Undr1= in the CALIBRATION section) and will drive solid state relay
resistive loads of 200 ohms or greater. PIN NUMBER FUNCTION
10 ............ PWC #1 OUT
2 ............. PWC #2 OUT
1 ............. PWC #3 OUT
9 ............. PWC #4 OUT
11 ............ PWC #5 OUT
13 ............ PWC #6 OUT
5 ............. PWC #7 OUT
4 ............. PWC #8 OUT
12 ............ COMMON
PIN NUMBER... FUNCTION
7 ............. GROUND
19 ............ GROUND
2 ............. Tx D
3 ............. Rx D
11 ............ Tx D RETURN
13 ............ Rx D RETURN
10 ............ Tx D SRC
12 ............ Rx D SRC
23 ............ Tx D ACTIVE
25 ............ Rx D ACTIVE
24 ............ GROUND
9 ............. +5 VDC
6 ............. +5 VDC
PIN 8 PIN 1
PIN 9
PIN 15
PWC Output
figure no. 5 - preset weight comparator output
BI-DIRECTIONAL SERIAL INTERFACE (Serial I/O)
An RS23220mA compatible bi-directional serial interface
connector is located on the back of the instrument and may
be used for various functions.It will accept serial commands*
allowing the 748 to be controlled remotely. Figure no. 6
illustrates the pin layout for this connector.
* See SERIAL INPUT COMMANDS section for details.
figure no. 6 - bi-directional interface
Serial I/O
INTERCONNECT CABLE - Example A
CONNECTION DIAGRAM
for 20 mA
CURRENT LOOP OPERATION
Peripheral Device has
PASSIVE END
of Current Loop
(standard enclosure only).
+Y
TX SOURCE 10 RX RETURN
TWISTED PAIR
TX RETURN 11 RX ACTIVE
TX ACTIVE 23
- - - - - - - - - 24
RX SOURCE 12 TX RETURN
TWISTED PAIR
RX RETURN 13 TX ACTIVE
RX ACTIVE 25
- - - - - - - - - 24 CHASSIS GND
INTERNAL
CIRCUITRY PERIPHERAL
DEVICE;
PASSIVE END
SERIAL
CONNECTOR;
ACTIVE END
Refer to
applicable
information for
required
connections.
RX RETURN 13 TX SOURCE
TWISTED PAIR
RX ACTIVE 25 TX RETURN
TX RETURN 11 RX SOURCE
TWISTED PAIR
TX ACTIVE 23 RX RETURN
CHASSIS GND
INTERNAL
CIRCUITRY PERIPHERAL
DEVICE;
ACTIVE END
SERIAL
CONNECTOR;
PASSIVE END
Refer to
applicable
information for
required
connections.
INTERCONNECT CABLE - Example B
CONNECTION DIAGRAM
for 20 mA
CURRENT LOOP OPERATION
Peripheral Device has
ACTIVE END
of Current Loop
(standard enclosure only).

5
NEMA 4X ENCLOSURES
For desk mounting of the 748 in the NEMA 4X enclosure, it is necessary to order separately a
“DESK-MOUNT” kit. Refer to Assembly Instruction for Desk-Mount Kit (8539-M097-O1) for mounting
instructions.
The Model 748 in a NEMA 4X enclosure is normally mounted on the wall or some other vertical
surface.The enclosure is attached to the wall with four (4) bolts.Refer to Figure No.7 for the hole
layout for the NEMA 4X enclosure.
First make certain that the location chosen is free from sudden changes in temperature and that the
mounting surface is strong enough to support the enclosure while being close enough to provide the
operator easy access to the keyboard. Carefully layout the mounting hole locations then drill and
install the anchor bolts.Attach the enclosure to the wall and securely tighten the retaining bolts.
Continue by opening the front cover on the instrument enclosure. Loosen all four (4) retaining
screws and rotate each of the clips to the side. DO NOT remove these screws. Fully open the front
cover of the instrument exposing the internal printed circuit board.
LOAD CELL CONNECTION
CAUTION! Disconnect any external load cell power supply before connecting load cells to
the instrument. Failure to do so will result in permanent damage to the instrument.
Loosen the cable gland connector for the load cell.This gland connector is located on the bottom of
the enclosure on the right-hand side. Refer to figure no.10 for an illustration of the connector layout.
Slip the single cable from the load cell or load cell junction box through the gland connector and into
the enclosure.Remove 2" of the outer insulation jacket then remove 1/4" of insulation from each of
the four (4) wires and shield without sense leads or six (6) wires and shield with sense leads (refer
to figure no. 8). Connect each of the wires to terminal block P1 as shown in figure no. 11.To
terminate a wire, first press down on the release bar for the terminal, insert the wire into the terminal
opening then allow the release bar to return to
its original position, locking the wire in place.
Repeat the procedure until all of the wires are in
place. NOTE! If the sense leads are NOT used,
you must install plug-in jumpers at J1 and J3
adjacent to the terminal block.These jumpers
attach the sense leads to the excitation leads.If
sense leads ARE used (as in motor truck
scales), these plug-in jumpers should be
positioned on one plug-in pin only or removed
and stored for later use.
Terminal
2" 1/4"
figure no. 8 - terminal
block connections
14.0"
6.0"
4.6"
8.6"
13.5"
0.312"
Dia
figure no. 7 - NEMA 4X enclosure
mounting hole layout

6
PRINTER CABLE INSTALLATION
Loosen the gland connector adjacent to the load cell cable gland connector (see figure no. 10) and
slip the printer cable through it and into the enclosure.Remove 2" of the outer insulating jacket from
the cable, then remove 1/4" of insulation from each of the wires (refer to figure no.8).These wires are
to be connected to terminal block P9 at the bottom edge of the printed circuit board.Refer to figure no.
10 for the location of the terminal block.
Note that the printer output can be either RS232 compatible or 20mA current loop.To terminate the
wires, first press down the release bar on the terminal. Slip the wire into the terminal opening and
release the bar to lock the wire in place.
BI-DIRECTIONAL SERIAL INTERFACE (Serial I/O)
The bi-directional serial interface for the NEMA 4X version of the 748 Weight Indicator is located on
the printed circuit board. Note that because of the number of signals involved, there is no terminal
block for the bi-directional serial interface.Rather, a 25-pin “D” connector has been provided for the
interface. All terminations to this interface must be made to a mating connector (Cardinal part no.
6610-2047) plugged into the serial interface. Figure no.11 identifies the location of this connector.
Refer to the bi-directional serial interface section of the DESKTOP ENCLOSURE INSTALLATION
section for identification of the connector pins.
PRESETWEIGHT COMPARATOR
The 748 Preset Weight Comparator comes standard with Logic Level Outputs that can control solid
state external devices. An optional relay assembly must be used to power AC powered devices. If your
748 is equipped with the optional feature, PWC relay assembly, be sure to follow the connection
instructions under that section to prevent damage to your indicator.
PWC LOGIC LEVEL OUTPUT
To automatically switch external devices at up to eight preset weight values, connect solid state relays
to the PWC OUTPUT connector P11 as shown in figure no.9.When the displayed weight is equal to
or greater than the preset weight (see KEYPAD FUNCTIONS: PRESET key), the PWC output
changes from 0 volts dc to 5 volts dc and will drive solid state relay resistive loads of 200 ohms or
greater.
To connect the control cable to the comparator outputs, first loosen the gland connector located on the
bottom of the enclosure on your right side. Refer to figure no. 10 for the location of the connector. Slip
the cable through this connector and into the enclosure. Remove 2" of the cable insulating jacket then
1/4" of insulation from each of the wires.Refer to figure no. 8, then make the proper terminations on
terminal block P11.To terminate a wire, first press the release bar for the terminal, insert the wire into
the terminal opening, then allow the bar to return to its original position locking the wire in place.
PWC RELAY ASSEMBLY
To automatically control power to up to eight AC powered devices at programmed weight values,
unplug the four-position screw terminal from the relay board and wire as shown in figure no. 9.
Two identical PWC relay boards are configurable for PWC’s 1-4 or 5-8 by removable plug-in jumpers.
The relay board(s) are mounted to the NEMA 4X enclosure bottom or back (between the battery cover
and the side of the enclosure) or in an external junction box for use the the desktop enclosure.
NEMA 4X Internal PWC Relay Assembly Desktop External Relay Junction Box
-R4: 4 Relay Assembly RB4: 4 Relay Assembly
-R8: 8 Relay Assembly RB8: 8 Relay Assembly
OUTPUT (closed)........ 28-240VAC @ 3A maximum for each plug-in relay.
CONTROL INPUT....... 5VDC @ 12mA from the 748 NEMA 4X main pc board assembly P11 or the
desktop PWC OUTPUT connector.
CONNECTION ............Removable plug-in screw terminals for up to 14 AWG wire.
The individual relays can be configured to be on (closed) or off (open) at weights under the preset
weight and switch at the preset weight from on-to-off or off-to-on by setting the under weight condition
to on or off during setup and calibration or setup review.
EXAMPLE: Undr1=on.. . PWC1 relay is on (closed) for weights under the preset weight and off
(open) for weights equal to or over the preset weight.

7
Printer
Cable
Power
Supply
Cord Optional
I/O Board
Connector
Load Cell
Input
Terminals
Load Cell
Cable
PWC Output
Cable
Calibration
Switch
Serial
I/O Cable
PWC Relay
Board
K4K3K2K1
L1 L1 3/7 4/8L1 L1 1/5 2/6
PWC1 PWC2 PWC3 PWC4 PWC5 PWC6 PWC7 PWC8
P1
1
PWC PWC
L2 L1
LOAD
3.0A MAX
LOAD
3.0A MAX
LOAD
3.0A MAX
LOAD
3.0A MAX
8539-C062-0A
(28-240 VAC)
Fuse
3-12 Amp
User Supplied
P11
(Main Board)
Terminal
Number
3
4
2
1
5
8
9
7
6
1 Brown
2 Red
3 Orange
4 Yellow
5 Green x
6 Blue
7 Violet
8 Green
9 White
10 Gray
PWC Number
3
4
2
1
OPEN
5
8
GROUND
7
6
P1
(Relay Board)
figure no. 10 -
748 NEMA 4X
enclosure layout
figure no. 9 -
PWC relay board
NEMA 4X MAIN BOARD (P11)TO RELAY BOARD (WIRE) CONNECTION
Connect the PWC cable wires to the printed circuit board connector P11.
NOTE! All relays are the normally open type that will open when power to the indicator is
lost.

8
figure no. 11 - PC board layout
NOTE! After all terminations have been made, remove the excess cable from the
instrument enclosure and securely tighten each of the cable gland connectors. Do not
over-tighten these connectors but make certain they are snug.DO NOT USE TOOLS!
Tighten with fingers!
DATA FORMAT SPECIFICATIONS
SERIAL DATA FORMAT
The serial data formats are defined during the setup and review functions. At these times, the
number of start, data and stop bits along with the baud rate is selected for the serial interface. Baud
rates of 1200, 2400, 4800, 9600 and 19.2K baud are supported.
RECORD FORMAT
The information transmitted from the printer output port depends on the operation mode of the 748
at the time the PRINT key is pressed as well as the print format entered. Refer to the CALIBRATION
section of this manual for additional information on the programming of the printer output format.
Two general formats transmitted are shown in the illustration on.
GROSS WEIGHT MODE: NET WEIGHT MODE:
*^CR ID^nnnnnn *^CR ID^nnnnnn
*^CR hh:mm *^CR hh:mm
*^CR mm/dd/yyyy** *^CR mm/dd/yyyy**
*^CR xxxxxx^LB^G
*^CR xxxxxx^LB^T ^(Man Wt)
*^CR xxxxxx^LB^N
*Determined by tab settings
**Domestic - dd/mm/yyyy = international
where:nnnnnn = six (6) digits of numeric identification with leading zeros suppressed
hh = hours (refer to Setup for information on 12 or 24 hour time format selection)
mm = minutes (two (2) digits)
ss = seconds (two (2) digits)
MM = month (two (2) digits) (refer to Setup for information on date format
selection)
dd = day (two (2) digits)
P1
LOAD CELL
-Excitation
-Sense
-Signal
Shield
+Excitation
+Sense
+Signal
J3
J1
J5
P11
J12 DOM/INT Preset Weight
Comparator
Logic Level Output
P9 Printer
Output
Ground20Ma
RS232
Bi-Directional
Serial Interface
P7
P5
Connector for
Option PC Board
Display Outline
P3
Power Input
Connector
PWC 2
PWC 3
PWC 4
PWC 5
PWC 1 Common
PWC 8
PWC 7
PWC 6
Sense/Excitations
Jumpers J1 and J3
Auto-On
Jumper
Calibration
Switch
J5 VEXC SELECT
NORMAL CLOSED= 8V
OPTIONAL OPEN= 12v*
*(Must use 18 VDC power supply)
OPR CAL
CTS

9
yyyy = year four (4) digits)
ID = ASCII letters “I” and “D” to identify data as identification
LB = ASCII letters “L” and “B” to identify weighing units as pounds.May also be
KG for kilograms, OZ for ounces
xxxxxx = six (6) numeric digits of weight with decimal point if required and leading
zeros suppressed
G = ASCII letter “G”for gross weight
T = ASCII letter “T”for tare weight
N = ASCII letter “N” for net weight
CR = carriage return (followed by LF if Automatic Line Feeds was set toYES
during setup)
^ = space (hex 20)
LF = line feed
CONTINUOUS DATA OUTPUT
If, during setup and calibration, the answer to the prompt Sb400? is NO, the weight data will be
transmitted in the following format:
CRPzzzzzzDs^uu^m^^ETX
If the prompt Sb400? is answeredYES, the weight data will be transmitted in the following formats:
Pxxxxxx^UU^M^SS^CR (no decimal point in weight display)
PxxxxxxD^UU^M^SS^CR (decimal point in weight display)
where: CR - carriage return (hex 0D)
D - decimal point (embedded where necessary)
ETX - end of text (hex 03)
m - mode, lower case (g=gross, n=net)
M - mode, upper case (G=gross, N=net)
P - polarity (space if positive, - if negative)
s - status, lower case (m=motion, e=entry - input in progress, c=over
capacity)
SS - status, upper case (CZ=center-of-zero, MO=motion, BZ=gross weight
below zero, ee=entry - input in progress, OC=over capacity)
uu - units, lower case (lb, kg, tn, etc.)
UU - units, upper case (LG, KG, TN, etc.)
xxxxxx - weight with leading spaces
zzzzzz - weight with leading zeros
^ - space
WEIGHT ON DEMAND
If the bi-directional serial has not been setup for continuous output, the 748 will respond to a weight
request (ENQ).
The host device (computer) sends:
ENQ - (hex 05)
The 748 will respond:
Sxxxxxx^UU^M^CC^CR - if no decimal point in weight display.
SxxxxxxD6UU6M6CC^CR - if decimal point in weight display.
S - sign (space if weight is positive or a “--” if weight is negative)
xxxxxx - six digits of weight with leading zeros suppression
D - decimal point embedded in weight (if decimal point selected during
calibration)
UU - weighing units (lb or kg)
M - weighing mode (“G” if displaying gross weight, “N” if displaying net
weight)

10
motion - space if there is no motion or an “M”if there is motion
CC - weight status (“OC” if weight exceeds scale capacity, “BZ” of the weight
is below zero, “MO’ if there is motion)
CR - carriage return (0Dhex)
SERIAL INPUT COMMANDS
The second serial port on the 748 is a bi-directional port and can both receive and transmit serial
data. It is possible to control the operation of the 748 by transmitting serial commands to the
instrument via this serial port.This is accomplished by transmitting a command string which is then
acted upon as if it were received from the instrument’s keyboard.The basic format for this serial
command is: STX KeyCommand [SubCommand] [WeightValue] CKsum ETX
where: STX - Start of Text (hex 02) MUST precede ALL serial commands.
KeyCommand - One of a table of predefined command functions. Note: All
commands are subject to rejection just as commands from the
keyboard.
SubCommand - Optional command parameter.
Weight Value - Optional weight value required by some Key Commands. Note:
The weight value must meet the displayed division, capacity, and
decimal point precision of the indicator.
CKsum - XOR checksum of command (
excluding STX and ETX) Note: For
instructions on how to calculate the checksum value, refer to the
CHECKSUM CALCLATION section of this manual.
ETX - End of Text (hex 03) MUST terminate ALL serial commands.
The KeyCommand functions are:
KeyCommand - 0
Equivalent Keyboard Key - GROSS
Function - Switch 748 to Gross Weight Mode
Serial Command Format - STX0CKsumETX
Hex Format to Transmit - 02H 30H 33H 30H 03H
Equivalent Computer or Terminal Keys to press- Ctrl B 0 3 0 Crtl C
KeyCommand - 1
Equivalent Keyboard Key - NET
Function - Switch 748 to Net Weight Mode
Serial Command Format - STX1CKsumETX
Hex Format to Transmit - 2H 31H 33H 31H 3H
Equivalent Computer or Terminal Keys to press- Ctrl B 1 3 1 Ctrl C
Key Command - 2
Equivalent Keyboard Key - lb/kg
Function - Toggle the 748 beyween Lb and Kg modes
Serial Command Format - STX2CKsumETX
Hex Format to Transmit - 2H 32H 33H 32H 3H
Equivalent Computer or Terminal Keys to press- Ctrl B 2 3 2 Ctrl C
KeyCommand - 3
Equivalent Keyboard Key - ON/ZERO
Function - Zero the weight displaly
Serial Command Format - STX3CKsumETX
Hex Format to Transmit - 2H 33H 33H 33H 3H
Equivalent Computer or Terminal Keys to press- Ctrl B 3 3 3 Crtl C
KeyCommand - 4
Equivalent Keyboard Key - PRINT
Function - Initiate a print sequence at the printer serial port
Serial Command Format - STX4CKsumETX

11
Hex Format to Transmit - 2H 34H 33H 34H 3H
Equivalent Computer or Terminal Keys to press - Ctrl B 4 3 4 Ctrl C
KeyCommand - 5
Equivalent Keyboard Key - TARE
Function - Enter a Tare weight value
Serial Command Format - STX5xxxxxxCKsumETX
(xxxxxx = the tare weight value)
Hex Format to Transmit - 2H 35H xH xH xH xH xH xH1zzH23H
Equivalent Computer or Terminal Keys to press - Ctrl B 5 xxxxxx zz3Ctrl C
KeyCommand - 6
Equivalent Keyboard Key - BAR
Function - Enter the Bar Graph Starting (60) and Stop (61)
weight values
Serial Command Format - STX60xxxxxxCKsumETX
(xxxxxx = the Bar Graph Starting Weight)
STX61yyyyyyCKsumETX
(yyyyyy = the Bar Graph Stop Weight)
Hex Format to Transmit - 2H 36H 30H xH xH xH xH xH xH1zzH23H
(Start weight command)
2H 36H 31H yH yH yH yH yH yH2zzH23H
(Stop weight command)
Equivalent Computer or Terminal Keys to press - Ctrl B 6 0 xxxxxx zz3Ctrl C
(Start Weight command)
Ctrl B 6 1 yyyyyy zz3Ctrl C
(Stop Weight command)
NOTE: This command will not change from the PWC to Bar Graph mode in the display. It must be
manually selected.
KeyCommand - 7
Equivalent Keyboard Key - PRESET
Function - Enter the Preset or Trim weight value for one or all
eight of the preset weight comparators
Serial Command Format - STX7nxxxxxxCKsumETX
n = the preset or trim weight comparator number
(see below).
(xxxxxx = the weight value for the corresponding
preset number)
Hex Format to Transmit - 2H 37H nH xH xH xH xH xH xH1zzH23H
Equivalent Computer or Terminal Keys to press - Ctrl B 7 n xxxxxx zz3Ctrl C
Preset andTrim values for “n.”
Note values for“n” are in HEX.
1 set preset 1 7 set preset 4 D set preset 7
2 set trim 1 8 set trim 4 E set trim 7
3 set preset 2 9 set preset 5 F set preset 8
4 set trim 2 A set trim 5 G set trim 8
5 set preset 3 B set preset 6
6 set trim 3 C set trim 6
NOTE: This command will not change from the Bar Graph to PWC mode in the display. It must be
manually selected.
KeyCommand - 8
Equivalent Keyboard Key - none
Function - Initiates an inquiry (ENQ) of the bi-directional I/O
port.This command will cause the displayed
weight to transmit out the serial I/O port.

12
Serial Command Format - STX8CKsumETX
Hex Format to Transmit - 2H 38H 33H 38H 3H
Equivalent Computer or Terminal Keys to press- Ctrl B 8 3 8 Ctrl C
KeyCommand - 9
Equivalent Keyboard Key - none
Function - Perform Push Button Tare function.This will set the
GROSS weight as the TARE value and switch to
the NET mode.NOTE: The setup parameter,
PbtAr has no effect on this function
Serial Command Format - STX9CKsumETX
Hex Format to Transmit - 2H 39H 33H 39H 3H
Equivalent Computer or Terminal Keys to press- Ctrl B 9 3 9 Ctrl C
1The xH xH xH xH xH xH and yH yH yH yH yH yH are the HEX equivalent of each character in
the weight value. For example, if the weight value is 1234.1, the HEX equivalent is 31H 32H 33H
34H 2EH 31H.
2The zzH is the HEX equivalent of the ChecKsum value.NOTE: For instructions on how to
calculate the checksum value, refer to the CHECKSUM CALCULATION section of this manual.
3Refer to an ASCII character code table of your computer or terminal for the corresponding
key(s) to press for the HEX ChecKsum value.
RESPONSESTO SERIAL COMMAND FUNCTIONS
The 748 will respond to every serial command received.The format will serve to indicate the manner
in which the serial command was processed.The general format for the response to a serial
command is: Response [RejectCode]
where: Response - ACK if the command was processed
NAK if the command was not processed
RejectCode - If NAK was transmitted to show that the command was not
processed, a code number will be transmitted to indicate the
reason for rejection of the command
0 - Unable to process command (i.e.Print command sent while
weight was unstable)
1 - Invalid Cksum (i.e. checksum incorrectly calculated)
2 - Invalid Character Count (i.e. data length wrong, weight value
exceeds scale capacity or wrong division value, etc.)
3 - Invalid Decimal Point position (i.e. decimal point missing or in
wrong location)
4 - Invalid Command (i.e. improper command format or invalid
KeyCommand)
5 - Invalid Sub-Command (i.e. invalid tare weight, preset number,
or preset weight, Bar graph start or stop weight)
CHECKSUM CALCULATION
The checksum (Cksum) for KeyCommands with SubCommands or weight values to be entered (5,
6, and 7) are calculated by XORing each byte of the command,
excluding the STX and ETX
characters.The CKsum is then entered as a two (2) byte ASCII representation of the calculated
HEX value. For example:
TARE command (5): STX5xxxxxxCKsumETX (xxxxxx = tare weight value)
Tare Weight Value = 1234
CKsum = 1F (35h, XOR 31h XOR 32h XOR 33h XOR 34h XOR 2eh)
String to send, 02h 35h 31h 32h 33h 34h 2eh 31h 3fh 03h

13
Single byte KeyCommands (0, 1, 2, 3, 4, 8 and 9) are NOT XORed, instead the transmitted CKsum
is a two (2) byte ASCII representation of the HEX value of the command.For example:
GROSS command (0):STX030ETX
“0” = (30h)
Cksum = 30
String to send, 02h 30h 33h 30h 03h
PRINT command (4): STX434ETX
“4” = 4 (34h)
CKsum = 34
String to send, 02h 34h 33h 34h 03h
CALIBRATION
Your 748 indicator has been thoroughly tested and calibrated before being shipped to you. If you
received the indicator attached to a scale, calibration is not necessary. If the 748 is being connected
to a scale for the first time or recalibration is necessary for other reasons, proceed as indicated.
The calibration toggle switch is located on the main printed circuit board. If you have a NEMA 4X
enclosure you may gain access to this switch simply by opening the door on the enclosure.The
calibration switch is identified in figure no. 11.
If you have a 748 desktop enclosure, it will
be necessary to remove one of the end caps
from the enclosure to gain access to the
calibration switch.To do this, first remove the
instrument from the gimbal mounting by
removing the two (2) large knobs. Make
certain that the smaller locking screw on one
side is first loosened. Next, remove the top
and bottom screws from the right end cap
(see figure no. 12).The switch is located on
the printed circuit board near the center.
Once you have located the calibration switch
proceed with the calibration instructions.A
summary of the calibration process is shown
in graphical form at the end of this section.
SETUP AND CALIBRATION
CAUTION: The membrane keyboard is not to be operated with pointed objects (pencils,
pens, fingernails, etc). Damage to keyboard resulting from this practice will NOT be
covered under warranty.
0 = no 1 = yes
Press . Set the calibration switch on the printed circuit board to the CAL position then press
and release.Pressing the key will advance to the Prt= prompt.
Calibration
Switch
figure no. 12 - calibration
switch location
OFF
PRINT
ON
ZERO

14
CAUTION: When using the dual ranging feature of the 748, do not attempt to use a
division value in the low range that is too small to provide adequate signal strength for
stable operation of the instrument. Most scale installations will allow the smaller division
to be 1/2 of the larger division value when the dual range feature is used.
The inherent sensitivity and capabilities of the 748 will allow you to select combinations that are
beyond the practical limits of today’s load cells for dependable, stable performance.
The appearance of such a situation will be instability in the lower range, while the higher range will
operate as it should.
Press to show the current setting.Press to
disable or to enable.Press to save the displayed
setting.If dual ranging is disabled (0 entered) advance to
the INTERVAL SETTING, otherwise continue: (NOTE: If dual ranging is selected
and decimal point locations for both Intervals are not the same, the truck storage
feature will be inhibited.)
Press to show the current setting.Press
through to enter the new Interval value and press
to save it or to save the current value displayed.
Values are 1 through 9, 10, 20, 30, 40, 50, 60, 70, 80 and 90. (Interval values
other than 1, 2, 5, 10, 20 or 50 cannot be used in commercial applications.)
Press to show the current setting.Press
through to enter the desired decimal point location
and press to save it or to save the current displayed
setting. Must be the same as High Interval to be able to use Truck Storage.
0=XXXXXX 2=XXXX.XX 4=XX.XXXX
1=XXXXX.X 3=XXX.XXX
Press to show the current setting.Press
through to enter the new Low capacity value.Then
press to save it or to save the displayed value.
Press to show the current setting.Press
through to enter the new High interval value and
press to save it or to save the current displayed
setting. Available High interval values are 1 through 9, 10,
20, 30, 40, 50, 60, 70, 80 and 90. Interval values other than 1, 2, 5, 10, 20, or 50
cannot be used in commercial applications.
ENTER 0
1
dUAL r ENTER
Lo int
Lo dP
ENTER 0
9
ENTER
0
4
ENTER
ENTER
0
ENTER
9
ENTER
Lo CAP
0
9
ENTER
ENTER
DUAL RANGING
LOW INTERVAL
LOW DECIMAL POINT
LOW CAPACITY
HIGH INTERVAL
Hi int

15
Press to show the current setting.Press
through to enter the new High capacity value.Then
press to save it or to save the displayed value.
NOTE! High Capacity must be greater than Low Capacity and High Interval
must be greater than Low Interval. ADVANCETO WEIGHING UNITS.
Press to show the current setting.Press
through to enter the new Interval value and press
to save it or to save the current setting. Available interval
settings are 1 through 9, 10, 20, 30, 40, 50, 60, 70, 80 and 90. Interval values
other than 1, 2, 5, 10, 20, or 50 cannot be used in commercial applications.
Press to show the current setting.Press
through to enter the new decimal point location and
press to save it oo save the current setting.
0=XXXXXX 2=XXXX.XX 4=XX.XXXX
1=XXXXX.X 3=XXX.XXX
Press to show the current setting.Press
through to enter the new Capacity value.Then press
to save it or to save the displayed setting.
NOTE! Capacity cannot exceed 999999.
Press to show the current setting.Press through
to enter the new weighing units and press
to save it or to save the current displayed setting.
Press to show the current setting.Press through
to enter the desired decimal point location and press
to save it or to save the current setting. Must be the
same as Low Decimal Point to be able to use Truck Storage.
0=XXXXXX 2=XXXX.XX 4=XX.XXXX
1=XXXXX.X 3=XXX.XXX
Hi dP ENTER 0
HIGH DECIMAL POINT
4
ENTER
int=
Hi CAP
ENTER
0
9
ENTER
0
9
ENTER
ENTER
1=Pounds only 3=Pounds/Kilograms 4=Kilograms/Pounds 5=Tons (tn) only
(powers up and (powers up and
Calibrates Calibrates
2=Kilograms only in Pounds) in Kilograms) 6=Metric Tons (t) only
0
6
ENTER
9
ENTER
CAP=
UnitS= 1ENTER
ENTER
HIGH CAPACITY
INTERVAL SETTING
DECIMAL POINT SETTING
CAPACITY
WEIGHINGUNITS
4
0
ENTER
ENTER
dP=

16
Press to show the current selection - eitherYES or
NO. Press to bypass the calibration process or press
to proceed. Press after making your selection.
If NO is selected, the 748 will advance to the ZEROTRACKING RANGE.
CALIBRATION
CAL?
ENTER
0
1ENTER
This is the first of two calibration weights:NO LOAD or
ZERO and the TEST WEIGHTS or TEST LOAD. Press the
key and the display will show 0for NO LOAD. If the
first calibration weight is to be ZERO or NO LOAD, press the
key again. If the first calibration weight is to be theTEST WEIGHTS, key in the
total value of the calibrated test weights.Place these test weights on the scale
platform and press the key. After a few seconds, the display will show:
This is the second of two calibration weights. If the first
weight (CAL1) was zero, this weight should be equal to
the test weight total. If, however, the first weight was the
test weight total, then this weight should be zero. Press the
key.The display will show 0. If this second
calibration weight is to be zero, make certain the scale platform is empty then
press the key again. If this second calibration weight is to be the test load,
use the numeric keys and enter the total of the calibrated test weights. Place the
weights on the scale platform and press the key. After a few seconds the
display will show:
“C” NUMBERS
STORE DEADLOAD VALUE
Press to show the current value of the C1 number. If
the 748 was calibrated previously and you recorded the
four (4) “C” numbers, you may enter the value for C1.By
entering the “C” numbers previously recorded, you can return to that calibration
setting without having to use test weights.* If you wish to use test weights for
calibration, leave the C1 value unchanged and press the key.
If “C” numbers were entered, remove all weight from the
scale, press then press to display YES. Press
to store the current scale weight as the deadload
weight.
StodL= 1
ENTER
ENTER
ENTER
ENTER
C1=
FIRST CALIBRATION WEIGHT
SECOND CALIBRATION WEIGHT
ENTER
CAL 1=
CAL 2=
ENTER
ENTER
ENTER
ENTER
ENTER

17
ENTER
* If any components have been changed that affect calibration and your scale is used in a
commercial application and must be “Legal forTrade” you cannot use “C” numbers to re-calibrate.
Press to show the current settting.Press or
to enter the new setting and press to save it or
to save the current setting.
no (0) = Bar Graph readout is disabled YES (1) = Bar Graph readout is
enabled.
NOTE! If bAr= is set to NO, the BAR key is also disabled and
Error will display if the key is pressed.
1
0
ENTER
BAR GRAPH ENABLE/DISABLE
bAr=
ZERO TRACKING RANGE
4% ZERO RANGE
Press to show the current setting.Press through
to enter the new automatic zero tracking range.Then
press to save it or to save the current setting.
Allowable values are: 0.0 (disables Zero Tracking), .5 and 1 through 9.
Press to show the current setting.Press or
to enter the new limit for zero range.Then press to
save it or to save the current setting.
no = Full Capacity (No Limit) YES = 4% of Scale Capacity
0
trA=
trL=
0
9
ENTER
ENTER
ENTER
ENTER
1
POWER-UP ZERO FEATURE
FILTERING
Press to show the current setting.Press or
to enter the new setting and press to save it or to
save the current setting.
no = No Re-Zero on Power-Up YES = Automatic Re-Zero on Power-Up
Press to show the current setting.Press
through to enter the new filtering level.Then press
to save it or to save the current filter setting.
0= No Filtering 2= Moderate Filtering
1= Minimal Filtering 3 = Custom Filtering
If you selected 0, 1 or 2, advance to MOTION RANGE.
0
3
ENTER 1
ENTER
PUO=
FLt= 0
ENTER
ENTER

18
FYOU SELECTED LEVEL 3 FILTERINGTHEN:
BREAK RANGE
Press to show the current filter setting.Press
through to enter the new filter value (1 to 16).The
larger the number, the greater the effect.Then press
to save it or to retain the current setting. Filter is the number of weigh samples
that will be averaged before being displayed. If F=6, the weight value placed in
the display will be the average of the last six (6) consecutive weigh samples.
Press to show the current break range setting. Press
through to enter the new break range (1 to 64).
The larger the number the greater the weight change
required to break out of the filtering. Press to save the new value or to save
the current displayed value of break range.
F=
br=
9
ENTER
ENTER
0
09
ENTER
ENTER
Press to show the current setting.Press through
to enter the new value for the motion range.Weight
changes greater than this number of divisions will indicate
motion. Press to save the new setting or to save the current motion range
setting.
UnSt=
1
9
ENTER
ENTER
MOTION RANGE
BLANK ON MOTION
SAMPLE RATE
AUTOMATIC SHUTOFF (Battery Operation Only - see SETUP REVIEW)
Press to show the current setting.Press or
to enter the new setting.Then press to save it
or to save the current setting.
no = Do Not Blank Display On Motion YES = Blank Display On Motion
Press to show the current sample rate. Press
through to enter the new Sample Rate (1 to 12
samples per second).Then press to save it or to save
the current setting.
Press to show the current setting.Press through
to enter the new setting.Then press to save it
or to save the current setting.
0= Disable Automatic Shutoff 1through 9- Number of Minutes of
Inactivity (No Motion)
Before Power Off
0
ENTER
1ENTER
bL=
Sr=
ASH=
ENTER
ENTER
ENTER
9
ENTER 0
0
9

19
SLEEP MODE (Battery Operation Only - see SETUP REVIEW)
PRESETWEIGHT COMPARATORS
Press to show the current setting.Press through
to enter the new setting.Then press to save it
or to save the current setting.Weight applied to scale, or
key pressed, will enable system operation.
0= Disable Sleep Mode 1through 9- Number of Minutes at
Zero (Zero Indicator On)
Before Going to Sleep
Press to show the number of presets. Press
through to enter the new number of preset weight
comparators.Then press to save it or to save the
current setting.
PSEtS=
SLP=
ENTER
0
ENTER
9
ENTER
ENTER
8
0
PWC OUTPUT STATE: UNDER PRESET WEIGHT VALUE
TRUCK STORAGE
PUSH BUTTON TARE
If 1 or more presets were entered, this prompt will appear
for each preset entered - the 1 position will indicate the
PWC number.Press to show the current setting for
the PWC output. on indicates that the PWC output is high (the PWC relay is on)
at weights under or less than the preset weight and will switch to off (the PWC
relay is off) at the preset weight and above. oFF indicates that the PWC output is
low (the PWC relay is off) at weights under the preset weight and will switch to on
(the PWC relay is on) at the preset weight and above.Press the key for off
and the key for on.
Press to show the current setting.Press or
to enter the new setting. Press to save the
new setting or to save the current setting.This question will
not appear if Dual Ranging was selected and the decimal point setting for the
High Interval differs from the decimal point setting for the Low Interval.
no= No Truck Storage YES= Truck Storage
Press to show the current setting.Press or
to enter the new setting.Then press to save it or to
save the current setting.
no = Numeric Tare YES= Push Button Tare Only
0
1
ENTER9
Undrl=
trSto=
PbtAr=
ENTER
ENTER
0
ENTER
0 1ENTER