Transcell Technology PC35, PC70, PC 150 Service Manual

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Page 1

North American Service Manual

MODEL PC SERIES

Version 2 March 25, 1997

Revision B1.1 April 4, 2000

Prepared by

TRANSCELL TECHNOLOGY, INC.

Page 2

TABLE OF CONTENTS

Page

Chapter 1: Introduction............................................................................................................... 1-1

Chapter 2: Legal for Trade Sealing ............................................................................................ 2-1

2.1 Overview.................................................................................................................. 2-1

2.1.1 Sealing the Scale......................................................................................... 2-1

Chapter 3: General Troubleshooting Flowchart .......................................................................... 3-1

Chapter 4: Illustrated Parts List.................................................................................................. 4-1

4.1 PC-30 & PC-70......................................................................................................... 4-1

4.2 PC-150..................................................................................................................... 4-3

Chapter 5: Assembly / Disassembly........................................................................................... 5-1

5.1 PC-30 & PC-70......................................................................................................... 5-1

5.2 PC-150..................................................................................................................... 5-2

Chapter 6: Internal Wiring Diagram ............................................................................................ 6-1

Chapter 7: Theory of Operation.................................................................................................. 7-1

7.1 Theory of Operation Overview.................................................................................. 7-1

7.1.1 Main Board Assembly .................................................................................. 7-1

7.1.2 Display/Key Board Assembly........................................................................ 7-1

Appendix A: Technical Specifications........................................................................................... A-1

Appendix B: Serial Data Formats Information............................................................................... B-1

B.1 Serial Data Formats.................................................................................................. B-1

B.1.1 Serial Data Formats Overview ..................................................................... B-1

B.1.2 Consolidated Controls Demand Format........................................................ B-1

B.1.2.1 Recognized Host Commands......................................................... B-1

B.1.3 Consolidated Controls Continuous Format.................................................... B-2

B.1.4 Toledo 8213 Demand Format....................................................................... B-3

B.1.4.1 Recognized Host Commands......................................................... B-3

B.1.5 NCI 3800 / Triner Demand Format............................................................... B-4

B.1.5.1 Recognized Host Commands......................................................... B-4

B.1.6 Transcell Technology Demand Format......................................................... B-5

B.1.6.1 Recognized Host Commands......................................................... B-5

B.1.7 Transcell Technology Continuous Format..................................................... B-6

B.1.8 Detecto Demand / Continuous Format.......................................................... B-7

B.1.8.1 Recognized Host Commands......................................................... B-7

Page 3

B.1.9 Fairbanks 70-2453-4 Demand Format.......................................................... B-8

B.1.9.1 Recognized Host Commands......................................................... B-8

Appendix C: Circuit Diagrams ....................................................................................................... C-1

LIST OF FIGURES

1-1 PC Series Front Panel........................................................................................................ 1-1

2-1 Location of Calibration Switch............................................................................................ 2-1

2-2 Detail of Calibration Switch ................................................................................................ 2-1

5-1 Opening up the PC-30 and PC-70 Base Unit...................................................................... 5-1

5-2 Opening up the PC-150 Base Unit...................................................................................... 5-3

6-1 PC Series Chassis Wiring Diagram.................................................................................... 6-1

B-1 Consolidated Controls “Demand” Weigh Data Record........................................................ B-1

B-2 Consolidated Controls “Continuous” Weigh Data / Status Record....................................... B-2

B-3 Toledo 8213 “Demand” Weigh Data Record....................................................................... B-3

B-4 Toledo 8213 “Demand” Status Record ............................................................................... B-3

B-5 NCI 3800 / Triner “Demand” Weigh Data Record ............................................................... B-4

B-6 NCI 3800 / Triner “Demand” Status Record........................................................................ B-4

B-7 NCI 3800 / Triner “Demand” Invalid Command Record ...................................................... B-4

B-8 Transcell Technology “Demand” Weigh Data Record......................................................... B-5

B-9 Transcell Technology “Demand” Status Record.................................................................. B-5

B-10 Transcell Technology “Continuous” Weigh Data / Status Record........................................ B-6

B-11 Detecto Weigh Data / Status Record.................................................................................. B-7

B-12 Fairbanks “Demand” Weigh Data / Status Record.............................................................. B-8

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CHAPTER 1: INTRODUCTION

Service and maintenance personnel who desire more technical information than is presented in the PC Series User’s Guide should use this manual. Any component level troubleshooting or board replacement should be done by factory authorized personnel only.

The PC Series has three ranges of weight capacities. The PC-30 is a 30 lb (15 kg) scale, the PC-70 is a 70 lb (30 kg) and the PC-150 is a 150 lb (70 kg) scale.

GROSS

NET TARE ZERO

CLASS

Transcell Technology inc.

FIGURE 1-1: PC Series Front Panel

CAPACITY: 70 x 0.05 lb, 30 x 0,02 kg

III

Temp. Range: 0 to 40° C

ZERO

NET

GROSS

= 1500

max

TARE PRINT

lb kg

STABLE

MODEL

PC-70

1-1

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CHAPTER 2: LEGAL FOR TRADE SEALING

2.1 OVERVIEW

The scale can be prepared for commercial use by sealing access to the calibration switch, to meet the requirements for a legal-for-trade scale.

2.1.1 SEALING THE SCALE

Once calibration has been successfully completed, then the scale can be sealed as follows:

1. Referring to Figure 2-1, locate the calibration switch on the back of the scale.

2. Replace the calibration switch cover by securing with the two drilled head screws.

3. Thread a wire security seal through the openings in both drilled head screws. This prevents access to the calibration switch. Refer to Figure 2-2 for more detail.

Calibration Switch

Figure 2-1: Location of Calibration Switch

Drilled Head Screws

Figure 2-2: Detail of Calibration Switch Cover Plate with Drilled Head Screws

2-1

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3-1

CHAPTER 3: GENERAL TROUBLSHOOTING FLOWCHART

START

Does

Scale Turn On

YES

Try The Following In Order Of Appearance:

1. Replace AC Adapter.

2. Check the Display Cable.

3. Troubleshoot or Replace Main PCB.

Try The Following In Order Of Appearance:

3. Replace Load Cell.

4. Replace Main PCB.

2. Check Load Cell Wiring.

Does

Scale Weigh

YES

Try The Following In Order Of Appearance:

Do the

Keys Work

YES

1. Check Display Cable.

Try The Following In Order Of Appearance:

1. Check for proper AC Adapter Voltage .Is the

Scale Stable

YES

2. Check environment.

Try The Following In Order Of Appearance:

1. Check for platform obstruction (i.e. ovld stop).Is the

Scale Linear

YES

2. Replace load cell if zero offset count too high.

CALL

TRANSCELL

STOP

1.Try re-calibrating scale.

2. Troubleshoot or Replace Display PCB.

3. Troubleshoot or Replace Main PCB.

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CHAPTER 4: ILLUSTRATED PARTS LIST

4.1 PC-30 AND PC-70

4-1

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ITEM QTY PART NO. DESCRIPTION

1 1 380190008 Stainless Steel Platform 2 1 211040020 Load Cell – FAD-20 (PC-30) 2 1 211040045 Load Cell – FAD-45 (PC-70) 3 1 380190036 Bottom Spacer - Aluminum 4 1 380190037 Top Spacer - Aluminum 5 4 380190013 Adjustable Foot – 1 250116237 AC Adapter – 12 VDC, 500 mA

ITEM QTY PART NO. DESCRIPTION

1 1 215193811 Main Board Assy – 1 215366100 Display/Key Board Assy

4-2

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4.2 PC-150

4-3

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ITEM QTY PART NO. DESCRIPTION

1 1 380190008 Stainless Steel Platform 3 1 380360001 Top Spacer - Aluminum 5 1 211040100 Load Cell – FAD-100 6 1 380360007 Bottom Spacer - Aluminum 7 4 380190013 Adjustable Foot – 1 250116237 AC Adapter – 12 VDC, 500 mA

4-4

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CHAPTER 5: ASSEMBLY / DISASSEMBLY

5.1 PC-30 and PC-70 Tools Required: 5 mm Allen Wrench

Phillips Head Screwdriver

1. Remove the scale platter (1) and set aside.

2. Using the 5 mm Allen wrench, remove the [2] load cell mounting bolts (2).

3. Lift off the sub-platform assembly (3), and set aside.

4. Remove the [4] mounting screws (5) for the splash plate (4) and set aside.

5. Lift off the splash plate and set aside.

Figure 5-1: Opening up the PC-30 and PC-70 Base Unit

5-1

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5.2 PC-150 Tools Required: 5 mm Allen Wrench

Phillips Head Screwdriver

1. Remove the scale platter (1) and set aside.

2. Using the 5 mm Allen wrench, remove the [2] load cell mounting bolts (2).

3. Lift off the sub-platform assembly and aluminum spacer (3), and set aside.

4. Remove the [4] mounting screws (5) for the splash plate (4) and set aside.

5. Lift off the splash plate and set aside.

5-2

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Figure 5-2: Opening up the PC-150 Base Unit

5-3

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CHAPTER 6: INTERNAL WIRING DIAGRAM

6-1

RED GRN BLK WHT

5 2

Load Cell

DC Power Jack

Female DSUB9

JP2

– +

Main / ADC Board Assy

GND SCALE RXD SCALE TXD

RED

BLK RED

Setup Switch

On/Off Switch

1 2

LED

RED

GRN

BLK

WHT

1 2 3 4

E+ S+

E– S–

2 1

Ferrite Bead Core

1 2 3 4

Female 14-PIN CENTRONICS

TO REMOTE

DISPLAY/ KEY

UNIT (PC-30 &

1 2 3 4 5 6 7 8 9 10

10 9 8 7 6 5 4

3 2 1

PC-70 ONLY)

Display/Key Board Assy (PC-150 only)

Figure 6-1: PC Series Chassis Wiring Diagram

Page 15

CHAPTER 7: THEORY OF OPERATION

7.1 THEORY OF OPERATION OVERVIEW

Refer to Appendix C for reference designators.

7.1.1 MAIN / ADC BOARD ASSEMBLY

Power to the scale is supplied by a 12 VDC, 500 mA adapter. Regulator U1 supplies +5 VDC to the digital components. Regulator U8 supplies + 10 VDC to the analog components including load cell excitation. Switching regulator V5 inverts the + 10 VDC to – 10 VDC to act as the negative supply rail. Regulators V4 and V6 further regulate to ± 8 VDC for the A/D converter IC, U9.

Op-amp U11 forms a high impedance bridge amplifier for the load cell with a fixed gain of 100. Op-amp U10:B forms a low pass filter to prevent unwanted noise from entering the circuit. The other half of U10 (U10:A) provides a buffered reference voltage for op-amp U11. The A/D converter, U1, is a dual slope type converter. Timing is controlled by the microcontroller.

Microcontroller U2 executes several functions including A/D fetch, digital signal conditioning, key scan, serial communication, and display output. EEPROM U5 contains calibration data as well as the setup parameters. IC U7 is the EPROM, which contains program memory. The network around U4 boosts the MCU’s UART signal to RS-232 level for serial communication with a host device.

7.1.2 DISPLAY/KEY BOARD ASSEMBLY

This circuit contains footprints for 5 keys, display driver (U4) and the LED Display (U1-U3).

7-1

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APPENDIX A: TECHNICAL SPECIFICATIONS

ANALOG SPECIFICATIONS

Full Scale Input Signal 16 mV, including dead load Internal Resolution Approximately 150,000 counts Displayed Resolution Up to 3,500 graduations max Measurement Rate 10 Meas/sec, nominal System Linearity Within 0.02% of FS Calibration Method Software Calibration, with long term storage in EEPROM Excitation Voltage +10 VDC RFI Protection Signal lines protected by LC Low Pass Filters

Excitation & Power lines protected by EMI Chokes

DIGITAL SPECIFICATIONS

Microcontroller Intel 80C32

Program Memory: EEPROM:

32K x 8, external to µC 64 x 16, external to µC

SERIAL COMMUNICATIONS

RS-232 Full Duplex, Selectable Baud, Data Bits and Parity

OPERATOR INTERFACE

Display 6-Digit, 0.56” 7-segment LED Display Keyboard 5-key Tactile Keypad

POWER

AC Adapter 12 VDC, 500mA

ENVIRONMENTAL

Operating Temperature Storage Temperature

41°F (0°C) to 95°F (40° C)

-4°F (-20°C) to 167°F (+75°C) Operating RH 20% to 95%, non-condensing Storage RH 20% to 98%

PHYSICAL DIMENSIONS:

DC POWER

ON/OFF SWITCH

JACK

CALIBRATION

SWITCH COVER

13.0 in [330.2 mm]

RS-232

PORT

ID TAG

REMOTE DISPLAY CONNECTOR (WP-30 & 70 ONLY)

13.0 in [330.2 mm]

4.4 in [112 mm]

PC-150 Only

10.2 in [258.0 mm]

PC-30/70

A-1

Page 17

APPENDIX B: SERIAL DATA FORMATS INFORMATION

B.1 SERIAL DATA FORMATS

B.1.1 SERIAL DATA FORMATS OVERVIEW

The COM1 serial port is a full duplex RS-232 port designed for connection to a serial printer, computer, or remote display. Consult the PC Series Operation Manual for information on pinouts and cable diagrams.

Through the User Menu, you may choose one of the available SDF’s (Serial Data Formats). These serial data formats emulate certain makes of scales and make up the Application Layer. From a Data Link Layer perspective, there are two types: Demand and Continuous. Some SDF’s can be used with both types but most can be used with only one type.

For Demand types, the scale acts as the client and requires a host (usually a PC). The host issues a command (typically a single ASCII character) and the scale responds with a weigh data record, a status record or no record depending on the specific SDF chosen.

NOTE: Use Demand types for interfacing to a serial printer. In this case, data output can be initiated by pressing the PRINT key on the front panel of the scale. (Host is not required).

For Continuous types, host control is not required – but not restricted either. In this type, the scale automatically transmits a weigh data / status record out of the serial port at the end of each display update. Continuous types are used to interface to computers, scoreboards, and other remote devices requiring constant data updating. Host commands, although not required, are accepted and acted upon.

B.1.2 CONSOLIDATED CONTROLS DEMAND FORMAT

Figure B-1 shows the weigh data record sent to the host when the scale receives a Print (“P”) command. The same weigh data record is sent out of the serial port if the PRINT key is pressed on the scale’s front panel. If the weigh data is invalid, the scale does not respond. See section below for more information.

<STX> <POL> xxxxx.xx <LB/KG> <GR/NT> <CR> <LF>

Start Transmission

Polarity: <SP> = Positive "–" = Negative

Weight Data

SpaceSpace

Units: lb = pound kg = kilogram

FIGURE B-1. Consolidated Controls “Demand” Weigh Data Record

B.1.2.1 RECOGNIZED HOST COMMANDS

These commands are issued from the host to the scale and are single ASCII characters.

“P” - This command is sent to the scale to print the indicated display. The scale will

not respond if the scale is in motion, positive overload or negative overload.

Gross/Net: GR = Gross NT = Net

Carriage Return

Line Feed

Page B-1

Page 18

“Z” - This command is sent to the scale to zero the scale. The scale will disregard

this command if the scale is in motion, positive overload or negative overload. The scale will also disregard this command if it is not in gross mode or within the zero reset range. Even if successful, the host receives no response from the scale. The host must issue a “P” command to determine if the command was processed by the scale.

“T” - This command is sent to the scale to tare the scale. The scale will disregard

this command if the scale is in motion, positive overload or negative overload. The scale will also disregard this command if it displaying a negative gross value. Even if successful, the host receives no response from the scale. The host must issue a “P” command to determine if the command was processed by the scale.

“G” - This command is sent to the scale to revert to gross mode. The scale will

disregard this command if the scale is in motion, positive overload or negative overload. The scale will also disregard this command if it is not in net mode. Even if successful, the host receives no response from the scale. The host must issue a “P” command to determine if the command was processed by the scale.

“N” - This command is sent to the scale to revert to net. The scale will disregard

this command if the scale is in motion, positive overload or negative overload. The scale will also disregard this command if it is not in gross mode or a tare has yet to be established. Even if successful, the host receives no response from the scale. The host must issue a “P” command to determine if the command was processed by the scale.

“C” - This command is sent to the scale to toggle among the configured units. Even

if successful, the host receives no response from the scale. The host must issue a “P” command to determine if the command was processed by the scale.

B.1.3 CONSOLIDATED CONTROLS CONTINUOUS FORMAT

Figure B-2 shows the weigh data / status record automatically transmitted by the scale at the end of each display update. The same host commands listed in Section B.1.2.1 are accepted and acted upon by the scale.

<STX> <POL> xxxxx.xx <L/K> <G/N> <STAT> <CR> <LF>

Start Transmission

Polarity: <SP> = Positive "–" = Negative

Weight Data

Units: L = pound K = kilogram

Gross/Net: G = Gross N = Net

Status: <SP> = Valid M = Motion O = Over/under range

Carriage Return

Line Feed

FIGURE B-2. Consolidated Controls “Continuous” Weigh Data / Status Record

Page B-2

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B.1.4 TOLEDO 8213 DEMAND FORMAT

Figure B-3 shows the weigh data record sent to the host when the scale receives a Print (“W”) command. The same weigh data record is sent out of the serial port if the PRINT key is pressed on the scale’s front panel. If the weigh data is invalid, the scale responds with a status record instead – as shown in Figure B-4. See section below for more information.

NOTE: Since this SDF (Serial Data Format) does not support units of measure. It is recommended that lb/kg conversion be disabled.

Start Transmission

Weight Data

FIGURE B-3. Toledo 8213 “Demand” Weigh Data Record

Start Transmission

Invalid Weight

Status Byte: ( "1" = "True") See Table

Carriage Return

FIGURE B-4. Toledo 8213 “Demand” Status Record

B.1.4.1 RECOGNIZED HOST COMMANDS

These commands are issued from the host to the scale and are single ASCII characters.

Carriage Return

STATUS BYTE TABLE

Bit Function

B7 Parity bit B6

Always "1" Always "1"B5 Center of zero

Outside zero capture range

Under zero

B2 B1B0Out of range

Motion

“W” - This command is sent to the scale to print the indicated display. The scale

will respond with the status record if the weight is less than zero or the scale is in motion, positive overload or negative overload. Otherwise, the scale responds with the weigh data record.

“H” – Same as the “W” command except that the scale outputs an extra character

at the beginning and end of the weigh data record.

“Z” - This command is sent to the scale to zero the scale. The scale will disregard

this command if the scale is in motion, positive overload or negative overload. The scale will also disregard this command if it is not in gross mode or within the zero reset range. Whether the command was successful or not, the scale sends a status record to the host.

Page B-3

Page 20

“A” - This command is sent to the scale to request an acknowledgement. This

acknowledgement consists of two characters: <STX> and <CR>.

B.1.5 NCI 3800 / TRINER DEMAND FORMAT

Figure B-5 shows the weigh data record sent to the host when the scale receives a Print (“W”<CR>) command. The same weigh data record is sent out of the serial port if the PRINT key is pressed on the scale’s front panel. The status record is shown in Figure B-6. If an invalid host command is received, the scale responds with the invalid command record shown in Figure B-7. See section below for more information.

Line Feed

Weight Data

(1) Insert <SP> for Triner. (2) Insert <SP> for NCI. (3) Use lower case for NCI. (4) Insert <LF> for NCI.

<LB/KG>

Units (3): LB = pound KG = kilogram

<CR> (4)

Carriage Return

High Status Byte: See Table

Low Status Byte: See Table

FIGURE B-5. NCI 3800 / Triner “Demand” Weigh Data Record

Line Feed

High Status Byte: Same as "W"

<LSB>

<CR>

Carriage Return

Low Status Byte: See as "W"

<ETX>

End of Transmission

<LSB>

<ETX>

End of Transmission

Line Feed

High Status Byte Table

("1" = "True")

Bit Function

B3 B2 B1B0Not at zero

Low Status Byte Table

("1" = "True")

Bit Function

Not Used

B3 B2

Not Used

B1B0Over capacity

Under capacity

Carriage Return

Not Used Not Used

Motion

FIGURE B-6. NCI 3800 / Triner “Demand” Status

Record

B.1.5.1 RECOGNIZED HOST COMMANDS

These commands are issued from the host to the scale and consist of two ASCII characters.

“W”<CR> - This command is sent to the scale to print the indicated display. The

FIGURE B-7. NCI 3800 / Triner “Demand”

Invalid Command Record

host should check the status bytes to determine if the scale is in motion, positive overload or negative overload.

Page B-4

Page 21

“Z”<CR> - This command is sent to the scale to zero the scale. The scale will

disregard this command if the scale is in motion, positive overload or negative overload. The scale will also disregard this command if it is not in gross mode or within the zero reset range. Even if successful, the host receives no response from the scale. The host must issue an “S”<CR> command to determine if the command was processed by the scale.

“S”<CR> - This command is sent to the scale to request the status record.

B.1.6 TRANSCELL TECHNOLOGY DEMAND FORMAT

Figure B-8 shows the weigh data record sent to the host when the scale receives a Print (“P”) command. The same weigh data record is sent out of the serial port if the PRINT key is pressed on the scale’s front panel. If the weigh data is invalid, the scale sends the status record shown in Figure B-9. See section below for more information.

Start Transmission

Polarity: + = Positive – = Negative

Weight digits*

SpaceSpace

Units: lb = pound kg = kilogram

Carriage Return

Gross/Net: GR = Gross NT = Net

* with leading zero suppression

FIGURE B-8. Transcell Technology “Demand” Weigh Data Record

<STX>

Question

Mark

Start Transmission

Status Character 1: See Continuous Mode

<S2>

End Transmission

Status Character 2: See Continuous Mode

FIGURE B-9. Transcell Technology “Demand” Status Record

<ETX>

End Transmission

Line Feed

B.1.6.1 RECOGNIZED HOST COMMANDS

These commands are issued from the host to the scale and are single ASCII characters.

“P” - This command is sent to the scale to print the indicated display. The scale will

respond with the status record instead if the scale is in motion, positive overload or negative overload.

Page B-5

Page 22

“Z” - This command is sent to the scale to zero the scale. The scale will disregard

“T” - This command is sent to the scale to tare the scale. The scale will disregard

“G” - This command is sent to the scale to revert to gross mode. The scale will

“N” - This command is sent to the scale to revert to net. The scale will disregard

“C” - This command is sent to the scale to toggle among the configured units. Even

if successful, the host receives no response from the scale. The host must issue a “P” command to determine if the command was processed by the scale.

B.1.7 TRANSCELL TECHNOLOGY CONTINUOUS FORMAT

Figure B-10 shows the weigh data / status record automatically transmitted by the scale at the end of each display update. The same host commands listed in Section B.1.6.1 are accepted and acted upon by the scale.

<+/–> XXXX.XXX <UNITS> <S1> <ETX>

<STX>

Line Feed

Start Transmission

<LF>

Polarity: + = Positive – = Negative

Weight Data

<G/N>

Gross/Net: G = Gross N = Net

Units: LB = pounds KG = kilograms

<LF>

Line Feed

<S2>

End

Transmission

Status Character 2: 0 = valid 1 = Motion 2 = Zero 3 = Motion and Zero 4 = Not Ready

Status Character 1: 0 = valid 1 = Under 2 = Over

FIGURE B-10. Transcell Technology “Continuous” Weigh Data / Status Record

Page B-6

Page 23

B.1.8 DETECTO DEMAND / CONTINUOUS FORMAT

The Detecto SDF (Serial Data Format) can work both as a Demand type and a Continuous type, depending on the commands received from the host. Upon power up, the scale defaults to Demand type. The scale disregards the type setting programmed for Mode of Serial Transmission.

Figure B-11 shows the weigh data / status record sent to the host when the scale receives a Print (“~”) command. The same weigh data record is sent out of the serial port if the PRINT key is pressed on the scale’s front panel. The output records are identical when operating as a Demand type or a Continuous type.

NOTE: Since this SDF (Serial Data Format) does not support units of measure. It is recommended that lb/kg conversion be disabled.

Start Transmission

Polarity: <SP> = Positive – = Negative

Weight digits*

SpaceSpace

XX.X

OZ <SP>

Weight digits*

Space Checksum Byte 1

Status Byte: M = Motion C = Over

FIGURE B-11. Detecto Weigh Data / Status Record

B.1.8.1 RECOGNIZED HOST COMMANDS

These commands are issued from the host to the scale and are single ASCII characters.

“~” - This command is sent to the scale to print the indicated display. The host

should check the status bytes to determine if the scale is in motion, positive overload or negative overload.

“<SO>” - This command is sent to the scale to change the scale to Continuous

type. Even if successful, the host receives no response from the scale.

“<SI>” - This command is sent to the scale to change the scale to Demand type.

Even if successful, the host receives no response from the scale.

Checksum Byte 2

* with leading zero suppression

<ETX>

End

Transmission

NOTE: You can execute the <SO> and <SI> host commands by hitting Ctrl-N for

<SO> and Ctrl-O for <SI> on your computer’s keyboard.

Page B-7

Page 24

B.1.9 FAIRBANKS 70-2453-4 DEMAND FORMAT

Figure B-12 shows the weigh data / status record sent to the host when the scale receives a Print (<CR>) command. The same weigh data record is sent out of the serial port if the PRINT key is pressed on the scale’s front panel.

XXXX.XXX <UNITS> <GR/NT>

Weight digits*

SpaceSpace

Units: lb = pounds kg = kilograms

<SP>

Space Carriage

Two Status Bytes: GR = gross/stable gr = gross/unstable NT = net/stable nt = net/unstable

<SP>

Return

Space

* with leading zero suppression

FIGURE B-12. Fairbanks “Demand” Weigh Data / Status Record

B.1.9.1 RECOGNIZED HOST COMMANDS

These commands are issued from the host to the scale and are single ASCII characters.

“<CR>” - This command is sent to the scale to print the indicated display. The

scale will not respond if the scale is in positive overload. The host should check the status bytes to determine if the scale is in motion.

“Z” - This command is sent to the scale to zero the scale. The scale will disregard

this command if the scale is in motion, positive overload or negative overload. The scale will also disregard this command if it is not in gross mode or within the zero reset range. Even if successful, the host receives no response from the scale. The host must issue a <CR> command to determine if the command was processed by the scale.

<EOT>

End

Transmission

Carriage Return

“T” - This command is sent to the scale to tare the scale. The scale will disregard

this command if the scale is in motion, positive overload or negative overload. The scale will also disregard this command if it displaying a negative gross value. Even if successful, the host receives no response from the scale. The host must issue a <CR> command to determine if the command was processed by the scale.

“G” - This command is sent to the scale to revert to gross mode. The scale will

disregard this command if the scale is in motion, positive overload or negative overload. The scale will also disregard this command if it is not in net mode. Even if successful, the host receives no response from the scale. The host must issue a <CR> command to determine if the command was processed by the scale.

“N” - This command is sent to the scale to revert to net. The scale will disregard

this command if the scale is in motion, positive overload or negative overload. The scale will also disregard this command if it is not in gross mode or a tare has yet to be established. Even if successful, the host receives no response from the scale. The host must issue a <CR> command to determine if the command was processed by the scale.

Page B-8

Page 25

“C” - This command is sent to the scale to toggle among the configured units. Even

if successful, the host receives no response from the scale. The host must issue a <CR> command to determine if the command was processed by the scale.

Page B-9

Page 26

APPENDIX C: CIRCUIT DIAGRAMS

Please see attached schematic diagram sheets.

C-1