Rice Lake SCT-20 User manual

SCT-20 Series
Signal Conditioning Transmitter/Indicator
Technical Manual
PN 131128 Rev HMarch 2, 2022

© Rice Lake Weighing Systems. All rights reserved.
Rice Lake Weighing Systems® is a registered trademark of
Rice Lake Weighing Systems.
All other brand or product names within this publication are trademarks or
registered trademarks of their respective companies.
All information contained within this publication is, to the best of our knowledge, complete and
accurate at the time of publication. Rice Lake Weighing Systems reserves the right to make
changes to the technology, features, specifications and design of the equipment without notice.
The most current version of this publication, software, firmware and all other product
updates can be found on our website:
www.ricelake.com

Contents
© Rice Lake Weighing Systems ● All Rights Reserved i
Contents
Technical training seminars are available through Rice Lake Weighing Systems.
Course descriptions and dates can be viewed at www.ricelake.com/training
or obtained by calling 715-234-9171 and asking for the training department.
1.0 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Equipment Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 Installation Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.4 Weighing Instrument Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.4.1 Load Cell Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.5 Load Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.5.1 Load Cell Input Test (Quick Access) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.5.2 Load Cell Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.6 Connectivity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.7 Features of the SCT Weight Transmitter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.8 Electrical Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.9 LED Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.10 Key Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.11 Instrument Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.0 Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.1 Scale Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.1.1 Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.1.2 Theoretical Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.1.3 Maximum Capacity (NASS ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.1.4 Zero Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.1.5 Zero Value Manual Entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.1.6 Weight (Span) Calibration (With Test Weights) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.1.7 Setting Units of Measure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.1.8 Display Coefficient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.2 Filter On The Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.3 Zero Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.4 Serial Communication Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.4.1 RS-485 Serial Communication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.5 SCT-20 DeviceNet™ Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.6 Analog Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.6.1 Soldered Jumper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.6.2 Analog Output Type Scale Corrections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.7 PROFIBUS Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.8 SCT-20 EtherNet/IP™ Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.9 SCT-20 Ethernet TCP/IP Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.10 Outputs And Inputs Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.11 Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
2.12 Setpoints Programming. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2.13 Reserved For The Installer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2.13.1 Menu Locking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2.13.2 Menu Unlocking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2.13.3 Temporary Menu Unlocking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2.13.4 Default Scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
2.13.5 Program Selection - Reverse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
2.13.6 Program Selection - Not Legal: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
2.13.7 Keypad Or Display Locking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

SCT-20 Series
ii Visit our website www.RiceLake.com
Rice Lake continually offers web-based video training on a growing selection
of product-related topics at no cost. Visit www.ricelake.com/webinars
3.0 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.1 Semi-automatic Tare (Net/Gross) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.2 Preset Tare (Subtractive Tare Device) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.3 Semi-automatic Zero (Weight Zero-setting For Small Variations). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.4 Peak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.5 Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
3.6 SCT-20 DeviceNet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.7 PROFIBUS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
3.8 SCT-20 EtherNet/IP™. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.8.1 Instrument Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.8.2 Single Port EtherNet/IP Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.8.3 Dual Port EtherNet/IP Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.9 SCT-20 Ethernet TCP/IP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.10 Modbus/TCP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3.10.1 Set IP Address Via Telnet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3.10.2 Set IP Address with Lantronix Software. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
3.11 Modbus-RTU Protocol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
3.12 ASCII Bidirectional Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
3.13 Fast Continuous Transmission Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
3.14 Continuous Transmission Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
3.15 Interface to Remote Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
3.16 Communication Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
4.0 Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
5.0 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
5.1 FCC Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Introduction
© Rice Lake Weighing Systems ● All Rights Reserved 1
1.0 Introduction
Manuals and additional resources are available from Rice Lake Weighing Systems at www.ricelake.com/manuals
Warranty information can be found on the website at www.ricelake.com/warranties
1.1 Safety
Safety Signal Definitions:
Indicates an imminently hazardous situation that, if not avoided, will result in death or serious injury. Includes
hazards that are exposed when guards are removed.
Indicates a potentially hazardous situation that, if not avoided, could result in serious injury or death. Includes
hazards that are exposed when guards are removed.
Indicates a potentially hazardous situation that, if not avoided, could result in minor or moderate injury.
Indicates information about procedures that, if not observed, could result in damage to equipment or corruption
to and loss of data.
General Safety
Do not operate or work on this equipment unless this manual has been read and all instructions are understood.
Failure to follow the instructions or heed the warnings could result in injury or death. Contact any Rice Lake
Weighing Systems dealer for replacement manuals.
Failure to heed could result in serious injury or death.
There are no user serviceable parts. Refer to qualified service personnel for service.
The unit has no power switch, to completely remove D/C power from the unit, disconnect the D/C power cable from the main
socket.
For pluggable equipment the socket outlet must be installed near the equipment and be easily accessible.
Always disconnect from main power before performing any work on the device.
Do not allow minors (children) or inexperienced persons to operate this unit.
Do not operate without all shields and guards in place.
Do not use for purposes other then weighing applications.
Do not place fingers into slots or possible pinch points.
Do not use this product if any of the components are cracked.
Do not make alterations or modifications to the unit.
Do not remove or obscure warning labels.
Do not use near water.
DANGER
WARNING
CAUTION
IMPORTANT
WARNING

SCT-20 Series
2 Visit our website www.RiceLake.com
1.2 Equipment Recommendations
Failure to follow the installation recommendations is considered a misuse of the equipment.
To Avoid Equipment Damage
•Keep away from heat sources and direct sunlight.
•Protect the instrument from rain.
•Do not wash, dip in water or spill liquid on the instrument.
•Do not use solvents to clean the instrument.
• Do not install in areas subject to explosion hazard.
1.3 Installation Guidelines
If the unit gets too hot, it can stop communicating.
When the SCT-20 is installed inside of the electrical panel, it is recommended that the units be installed vertically to a horizontal
DIN rail. This minimizes heat buildup from multiple units being stacked and also enables optimal ventilation through the unit. If
possible, it is recommended that the unit be installed towards the bottom of a panel to avoid the warmest parts of the panel. If
panel size is small, some air circulation may be required.
1.4 Weighing Instrument Installation
The terminals to be connected to ground, as indicated on the SCT Weight Transmitter wiring guide, must have the same
potential as the scale structure ground. If unable to ensure this condition, connect a ground wire between the SCT Weight
Transmitter and the scale structure.
The load cell cable must be run separately to the SCT Weight Transmitter input and not share a conduit with other cables. A
shielded connection must be continuous without a splice.
Use RC filters (quencharcs) on the instrument-driven solenoid valve and remote control switch coils. To avoid electrical noise in
the SCT Weight Transmitter panel, use special filters or sheet metal partitions to isolate. The panel installer must provide
electrical protection for the instruments (fuses, door lock switch, etc.). It is recommended to leave the equipment powered on at
all times to prevent the formation of condensation.
Maximum Cable Lengths:
• RS-485: 1000 meters with AWG24, shielded and twisted cables
• RS-232: 15 meters for baud rates up to 19200
1.4.1 Load Cell Installation
The load cells must be placed on rigid, stable structures within 0.5% of plumb and level. It is important to use the mounting
modules for load cells to compensate for misalignment of the support surfaces.
Use waterproof sheaths and joints in order to protect the load cell cables.
Mechanical Restraints
When pipes are present, the use of hoses and flexible couplings and rubber skirted joints is recommended. In the event of rigid
conduit and pipes, place the pipe support or anchor bracket as far as possible from the weighed structure (at a distance at least
40 times the diameter of the pipe).
Welding
Avoid welding with the load cells already installed. If this cannot be avoided, place the welder ground clamp close to the
required welding point to prevent sending current through the load cell body.
Windy Conditions - Shocks - Vibrations
The use of weigh modules is strongly recommended for all load cells to compensate for misalignment of the support surfaces.
The system designer must ensure that the scale is protected against lateral shifting and tipping relating to shocks and vibration,
windy conditions, seismic conditions and the stability of the support structure.
IMPORTANT
IMPORTANT

Introduction
© Rice Lake Weighing Systems ● All Rights Reserved 3
Weighed Structure Grounding
Using a 10 gauge solid or braided wire or braided grounding strap, connect the load cell upper support plate with the lower
support plate, then connect all the lower plates to a single earth ground. Once installed, accumulated electrostatic charges are
discharged to the ground without going through or damaging the load cells. Failure to implement a proper grounding system
may not affect the operation of the weighing system; however, this does not rule out the possibility that the cells and connected
SCT Weight Transmitter may become damaged in the future. Do not ground using metal parts contained in the weighed
structure.
Figure 1-1. Installation Recommendations
1.5 Load Cells
1.5.1 Load Cell Input Test (Quick Access)
1. From the weight display, press for three seconds. is displayed.
2. Press . The response signal of the load cell is displayed, expressed in mV with four decimals.
3. Press three times to exit test mode.
1.5.2 Load Cell Testing
Load Cell Resistance Measurement (Use A Digital Multimeter)
• Disconnect the load cells from the instrument and check that there is no moisture in the load cell junction box caused by
condensation or water infiltration. If so, drain the system or replace it if necessary.
• The value between the positive signal wire and the negative signal wire must be equal or similar to the one indicated in
the load cell data sheet (output resistance).
• The value between the positive excitation wire and the negative excitation wire must be equal or similar to the one
indicated in the load cell data sheet (input resistance).
• The insulation value between the shield and any other load cell wire and between any other load cell wire and the body
of the load cell must be higher than 20 Mohm (megohms).
Load Cell Voltage Measurement (Use A Digital Multimeter)
• Remove the weight of the scale from the load cell to be tested.
• Make sure that the excitation wire of the load cell connected to the instrument is 5 Vdc +/- 3 percent.
• Measure the millivolt signal between the positive and the negative signal wires by directly connecting them to the multi-
meter. Make sure it reads between 0 and 0.5 mV.
• Apply load to the load cell and make sure that there is a signal increment.
If one of the above conditions is not met, please contact Rice Lake Weighing Systems Customer Support for
assistance.
Ground plate used to
continue ground
Structure used to
continue ground
IMPORTANT

SCT-20 Series
4 Visit our website www.RiceLake.com
1.6 Connectivity
Figure 1-2. Connectivity
1.7 Features of the SCT Weight Transmitter
• Weight indicator and transmitter for Omega/DIN rail mounting suitable for back panel; space saving vertical shape.
• Six-digit semi alphanumeric display (18 mm h), 7 segment.
• Four-key keyboard. Dimensions: 25 x 115 x 120 mm.
• Displays the gross weight; with an external contact capable of remote zeroing and gross/net switching.
• Peak weight function.
• Analog Output Option - Transmits the gross or net weight via opto-isolated analog output 16 bit, current 0-20 mA,
4-20 mA or voltage 0-10V, 0-5V (±0V / ±5V by closing a soldered in jumper).
The DeviceNet™ Option has a DeviceNet DP V0 Source port that allows the device to exchange the main system parameters
with a DeviceNet primary.
The PROFIBUS Option has a PROFIBUS-DP V0 Source port that allows the device to exchange the main system parameters
with a PROFIBUS primary.
The PROFINET-IO Dual Port Option allows exchange of the weight and the main parameters with a Profinet-IO controller.
The Ethernet Option has an EtherNet/IP™ device port that allows the device to exchange the main system parameters with an
EtherNet/IP scanner.
The Modbus/TCP Option has a Modbus/TCP device port that allows the device to exchange the main system parameters with
a Modbus/TCP primary.
The SCT Weight Transmitter transmits the gross or net weight via RS-485 serial port, by means of protocols:
• Modbus RTU
• ASCII bidirectional protocol
• Continuous transmission
Analog Output
(Current and Voltage)
Other Options
DeviceNet
PROFIBUS
PROFINET
Ethernet
PLC
Junction Box
MAX 8 Load Cells
In Parallel
3 Relay Outputs
PLC or Field Signals 2 Digital Inputs
(Opto-isolated,
Externally supplied)
Serial Port
RS-485
RS-232
Modbus RTU
DC Power
Supplier
(12-24 Volt)

Introduction
© Rice Lake Weighing Systems ● All Rights Reserved 5
1.8 Electrical Connections
Basic Information
• It is recommended that the negative side of the power supply be grounded.
• It is possible to power up to eight 350 ohm load cells or sixteen 700 ohm load cells.
• For 4-wire load cells, make a jumper between EX- and REF- and between EX+ and REF+.
• Connect terminal 0 VDC to the RS-485 common when interfacing to A/C powered equipment so that there is an opto-
isolated RS-485 connection.
• In the event of an RS-485 network with several devices, it is recommended to activate the 120 ohm termination
resistance on the two devices located at the ends of the network. See Section 2.4.1 on page 18.
Figure 1-3. Wiring Diagram
Three outputs: configurable setpoints or remote output management via protocol.
Two inputs: default of SEMI-AUTOMATIC ZERO input 1; NET/GROSS input 2. See Section 2.10 on page 24.
+ EXCITATION
- EXCITATION
4-wire load cell
connection
SHIELD
+ SIGNAL
- SIGNAL
1
2
3
4
5
6
RS485
Relay
Outputs
115Vac / 150mA
12-24Vdc
- SIGNAL
+ EXCITATION
SHIELD
- EXCITATION
- SENSE
+ SENSE
Inputs
5-24Vdc
+ SIGNAL
+-
Current output: max load 300 ohm
Voltage output: min. load 10 kohm
6-wire load cell
connection
Analog Output shown
See below for
DeviceNet, PROFIBUS,
Ethernet/IP or Modbus/TCP
RS485 Termination
POWER
EX
-
REF
-
1
EX
+
2
REF
+
3
SIG
+
6
IN1
7
IN2
8
IN COM
9
mA
10
V
11
mA-V COM
12
4
SIG
-
5
OUT1 OUT2 OUT3
OUT COM
+ RS485
- RS485
+ 12-24
0 VDC
13 14 15 18 19 20 16 17
SCT
20-AN
DeviceNet
CAN V-
10 11
12 13 14
CAN L CAN H CAN V+
CAN SHLD
CAN Termination
EX
-
REF
-
1
EX
+
2
REF
+
3
SIG
+
6
IN1
7
IN2
8
IN COM
9 4
SIG
-
5
PROFIBUS-DP
EX
-
REF
-
1
EX
+
2
REF
+
3
SIG
+
6
IN1
7
IN2
8
IN COM
9 4
SIG
-
5
Profibus Termination
Ethernet/IP
EX
-
REF
-
1
EX
+
2
REF
+
3
SIG
+
6
IN1
7
IN2
8
IN COM
9 4
SIG
-
5
EtherNet/IP
RJ-45
Profibus DP
Socket DB-9
Modbus/TCP
EX
-
REF
-
1
EX
+
2
REF
+
3
SIG
+
6
IN1
7
IN2
8
IN COM
9 4
SIG
-
5
Modbus/TCP
RJ-45
PROFINET-IO
EX
-
REF
-
1
EX
+
2
REF
+
3
SIG
+
6
IN1
7
IN2
8
IN COM
9 4
SIG
-
5
Profibus Termination
PROFINET-IO

SCT-20 Series
6 Visit our website www.RiceLake.com
1.9 LED Functions
Figure 1-4. Display
LED Main Function Secondary Function *
NET Net weight LED None
Zero LED (deviation from zero not more than +/- 0.25 divisions) LED lit: output 3 closed
Stability LED LED lit: output 2 closed
kg Unit of measure: kg LED lit: output 1 closed
g Unit of measure: g LED lit: input 2 closed
L Unit of measure: lb LED lit: input 1 closed
To activate the secondary LED function, press and hold , then press .
Table 1-1. LED Functions
LED Function
DeviceNet Model LED Function
DeviceNet Status
Blinks quickly: DeviceNet OK
Blinks slowly (about 0.5s): Initialization
LED lighted: source not initialized
LED off: DeviceNet KO
PROFIBUS Model LED Function
PROFIBUS Status Blinks quickly: PROFIBUS OK
Blinks slowly (about 0.5s): PROFIBUS error
PROFINET-IO Model LED Function
PROFINET Status Blinks quickly: PROFINET-IO OK
Blinks slowly (about 0.5s): PROFINET-IO error
EtherNet/IP Model LED Function
EtherNet/IP Status Blinks quickly: Ethernet OK
Blinks slowly (about 0.5s): EtherNet/IP KO
RJ45 Connector
Left side [Link LED]
Off: no link
Amber: 10 Mbps
Green: 100 Mbps
RJ45 Connector
Right side [Activity LED]
Off: no activity
Amber: half duplex
Green: full duplex
Modbus/TCP Model LED Function
Modbus/TCP Status Blinks quickly: Modbus/TCP OK
RJ45 Connector
Left side [Link LED]
Off: no link
Amber: 10 Mbps
Green: 100 Mbps
RJ45 Connector
Right side [Activity LED]
Off: no activity
Amber: half duplex
Green: full duplex
Table 1-2. Options LED Function
0

Introduction
© Rice Lake Weighing Systems ● All Rights Reserved 7
1.10 Key Functions
Figure 1-5. SCT Weight Transmitter Display and Keys
The LEDs are activated in sequence to indicate that a setting and not a weight is being viewed.
After pressing the first digit flashes and can be edited.
For numeric entries, press to select desired digit, then press to increment the digit.
KEY Short press in weigh mode
Long press
(3 sec) in weigh
mode Function within Setup Menus
Escape
—Zero Setting Escape from a parameter or return to previous menu or operation mode.
Scroll/ Backspace
Captures Tare
Gross  Net
Removes Tare
Net  Gross
Move to the previous parameter in a level or scroll to the next digit in a
parameter value.
Next/ Data Entry Save to alibi memory (if present) mV load cell test Move to the next parameter in a level or increment a value in a parameter.
Enter Setting setpoints and hysteresis —Move to next level of configuration or select and edit a parameter.
and Enter configuration for setting general parameters (press and hold then press to enter setup menu).
and Setting preset tare (press and hold then press to enter setup menu.
Table 1-3. Key Definitions
Note

SCT-20 Series
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1.11 Instrument Commissioning
1. Plug power cord into an outlet to power on the indicator. The display shows in sequence:
• followed by the software code ()
• followed by the software version ()
• followed by the hardware code ()
• The serial number ()
2. Check that the display shows the weight and that there is an increase in weight when loading the load cells. If there is
not, check and verify the connections and correct positioning of the load cells.
3. Confirm that the SCT Weight Transmitter has been theoretically calibrated, the load cell’s rated data is already entered
and that the plant system identification tag is present on the instrument and on the cover.
If the instrument has not been calibrated, follow the calibration instructions in Section 2.1.1 on page 10 before
proceeding to next step.
4. Reset to zero. See Section 2.1.4 on page 12.
5. Check the calibration with test weights and correct the indicated weight if necessary. See Section 2.1.6 on page 13.
6. Set the desired output type and the full scale value.
• Analog Output Model (Section 2.6 on page 19)
• DeviceNet Model (Section 2.5 on page 19)
• Ethernet Model (Section 2.8 on page 21)
• PROFIBUS Model (Section 2.7 on page 20)
• Modbus/TCP (Section 3.10 on page 43)
7. If using serial communication, set the related parameters. See Section 2.4 on page 16.
8. If setpoints are used, set the required weight values and the relevant parameters. See Section 2.10 on page 24 and
Section 2.12 on page 26.
Note

Configuration
© Rice Lake Weighing Systems ● All Rights Reserved 9
2.0 Configuration
2.1 Scale Menu
Figure 2-1. Scale Menu Structure
Parameter Options Description
 








Calibration (Section 2.1.1 on page 10)
 

Filter on the weight (Section 2.2 on page 15)
 


Zero Parameters (Section 2.3 on page 16)
 






Serial Communications settings (Section 2.4 on page 16)
 

DeviceNet options for outputs and inputs configuration (Section 2.10
on page 24)
Table 2-1. Configuration Parameters
W(6W2XW,Q

+
+
+
,Q
2XW
18&(/
Enter #
DeviceNet
Models
3W$U(6(W3
Profibus
Models
68$3
<(6
Q2
Ethernet
Models
*$W8$<
&
E
$
G
68EQ(7
&
E
$
G
3$GGU
&
E
$
G
6(U,$/
E$8G
G(8Q(W
Enter #
$GGU
6(W
$X72
7U$&
3$U$










),/W(U&$/,E
Analog
Models
$1$/2*
3U2), (W+Q(W
$GGU
Enter #
See Figure 2-2
on page 10.
See Figure 2-3
on page 16.
See Figure 2-5
on page 19.
See Figure 2-9
on page 24.

SCT-20 Series
10 Visit our website www.RiceLake.com
2.1.1 Calibration
Figure 2-2. Calibration Menu Structure
 





Analog options for outputs and inputs configuration
(Section 2.10 on page 24)
  PROFIBUS settings (Section 2.7 on page 20)
 



SCT-20 EtherNet/IP settings (Section 2.8 on page 21)
 




Outputs and Inputs configuration (Section 2.10 on page 24)
 


Test (Section 2.11 on page 25)
Parameter Options Description
FS-tEO  System Full Scale – determined by multiplying one load cell capacity by the number of load cells used.
Example of system full scale value calculation:
4 cells of 1000 kg ---->
FULL SCALE = 1000 X 4 = 4000
NOTE: The instrument is supplied with a theoretical full scale value  corresponding to 10000. To restore
factory values, set 0 as full scale.
Table 2-2. Calibration Menu Parameters
Parameter Options Description
Table 2-1. Configuration Parameters (Continued)
G,8,6 8(,*+W )6W(2
Enter #
6(Q6/E
Enter #
1$66
Enter #
=(U2
Enter # Enter #
,13
Enter #



















),/W(U 3$U$ 6(U,$/ W(6W2XW,Q$1$/2*
 6(W3
&$/,E
3W$U(
XQ,W &2())
/,WU(
E$U
$W1
3,(&(
Q(8WRQ
OE
2W+(U
+,/2*
+,/21
Q(81
*
W
Enter #

Configuration
© Rice Lake Weighing Systems ● All Rights Reserved 11
To calibrate the instrument, the theoretical calibration (Section 2.1.2 on page 12) must be completed first. After
theoretical calibration is set, the scale can be set with actual weights (Section 2.1.6 on page 13).
 0.50000-
7.00000

Sensitivity – a load cell rated parameter expressed in mV/V; set the average sensitivity value indicated on the load cells
Example of 4-cell system with sensitivity
2.00100, 2.00150, 2.00200, 2.00250;
enter 2.00175,
calculated as (2.00100 + 2.00150 + 2.00200 + 2.00250) / 4.
 1
2
5
10
20
50
100
0.0001
0.0002
0.0005
0.001
0.002
0.005
0.01
0.02
0.05
0.1
0.2
0.5
Division (resolution) – is the weight increment (display division size) that the scale counts by.
Settings: 0.0001 and 100 with x1 x2 x5 x10 increments.
 
max full scale
Maximum Capacity (Live Load/Product) – that can be displayed; when the weight exceeds this value by 9 divisions, dashes
display, indicating overload; setting this value to 0 disables the over capacity function.
 0 Zero – used to capture the deadload of the scale system; with the scale empty, the displayed value can be zeroed off; this
menu can also be accessed directly from the weighing mode to compensate for zero changes or variations;
Press to display the accumulated deadload weight that has been zeroed off.
 

Estimated Dead Load Value – of the scale when a scale contains product that cannot be removed; the value entered is the
dead load; this value is replaced if the zero function is performed
  Weight (Span) Calibration – after the theoretical calibration is complete and zero is set, the calibration can be adjusted with
actual test weights by changing the displayed value in this parameter
NOTE: If changes are made to the theoretical Full Scale ( ), the Sensitivity () or Divisions (
) parameters, the Weight (Span) Calibration is canceled and the theoretical calibration is initiated and
applied.
NOTE: If the theoretical full scale ( ) and the capacity full scale ( ) are equal in Weight (Span)
Calibration ( ), then the calibration currently in use is theoretical. If they are different, the calibration in
use is the Weight (Span) Calibration based on calibration weights.
NOTE: If changes are made to the theoretical full scale ( ), the capacity full scale ( ) or divisions
( ) parameters, all the system’s parameters containing a weight value will be set to default values
(setpoints, hysteresis, etc.).
 











Unit of Measure – determines the unit of measure to be displayed and printed.
See Section 2.1.7 on page 14 for unit descriptions.
  Multiplier Value – if entered, displays an alternative unit of measure if digital input is set for COEFF and is in a closed state
Parameter Options Description
Table 2-2. Calibration Menu Parameters (Continued)
Note

SCT-20 Series
12 Visit our website www.RiceLake.com
2.1.2 Theoretical Calibration
This function allows load cell rated values to be set. To perform the theoretical calibration set ,  and  in
sequence. See Figure 2-2 on page 10.
1. Press and hold , then press .  is displayed.
2. Press .  is displayed. Press .
3. Press or until total load cell capacity (system full scale) is displayed. Press .
4. Press or until  is displayed. Press .
5. Press or until desired load cell mV/V is displayed. Press .
6. Press or until  is displayed. Press .
7. Press or until desired display division size is displayed. Press .
8. Press twice to exit setup menu.
By modifying the theoretical full scale, the sensitivity or divisions, the Weight (Span) Calibration is canceled and only
the theoretical calibration is considered valid.
If the theoretical full scale and the recalculated full scale in Weight (Span) calibration (Section 2.1.6 on page 13) are
equal, this means that the calibration currently in use is theoretical calibration; if they are different, the calibration in
use is the Weight (Span) Calibration based on test weights.
By modifying the theoretical full scale, the sensitivity or divisions and all the system’s parameters containing a
weight value will be set to default values (setpoints, hysteresis, etc.).
2.1.3 Maximum Capacity ( )
Maximum capacity is the highest weight of live load/product that can be displayed. When the weight exceeds this value by 9
divisions, the following is displayed: ------. To disable this function, set to 0.
1. Press and hold , then press .  is displayed.
2. Press ,  is displayed.
3. Press or until  is displayed. Press .
4. Press or until desired capacity is displayed. Press .
5. Press twice to exit setup menu.
2.1.4 Zero Setting
Use Zero Setting to zero the scale after use or to compensate for variations due to environmental factors.
Perform this procedure after having set the theoretical calibration. See Section 2.1.2 on page 12.
This menu may also be accessed directly from the weight display. Press and hold for three seconds.
1. Press and hold , then press .  is displayed.
2. Press .  is displayed.
3. Press or until  is displayed. Press . The weight value to be set to zero is displayed and all of the
LEDs are flashing.
4. Press , the weight is set to zero and the value is stored to the permanent memory.
5. Press twice to exit set-up menu.
Press to display the accumulated deadload that has been zeroed off by the instrument, displaying the sum of all
of the previous zero settings.
Note
Note
Note

Configuration
© Rice Lake Weighing Systems ● All Rights Reserved 13
2.1.5 Zero Value Manual Entry
Perform this procedure only if it is not possible to zero off the scale structure, for example because it contains
product that can not be unloaded.
Enter the estimated structured dead load value that would be zeroed.
1. Press and hold , then press .  is displayed.
2. Press ,  is displayed.
3. Press or until  is displayed. Press .
4. Press or until desired dead load value is displayed. Press .
5. Press twice to exit set-up menu.
2.1.6 Weight (Span) Calibration (With Test Weights)
After performing the theoretical calibration (Section 2.1.2 on page 12) and the Zero setting (Section 2.1.4 on page 12), this
function allows calibration to be done using test weights of known value. If adjustment is required, change the displayed value
to display the test weight value.
1. Load the test weight onto the scale, use as high of a percentage of the maximum quantity to be weighed as possible.
2. Press and hold , then press .  is displayed.
3. Press .  is displayed.
4. Press or until  is displayed.
5. Press . The value of the weight currently on the system will be flashing on the display. All of the LEDs are off. (If
adjustment is not required, skip to step 8.)
6. Adjust the value on display to match weight loaded on the scale if necessary, by pressing or . The LEDs will
begin scrolling.
7. Press , the new set weight is displayed with all the LEDs flashing.
8. Press ,  will be displayed again.
9. Press twice to exit set-up menu.
Example:
For a system of maximum capacity of 1000 kg and 1 kg division, two test weights are available, one 500 kg and one 300 kg.
Load both weights onto the system and correct the indicated weight to 800. Now remove the 300 kg weight, the system must
show 500; remove the 500 kg weight, too; the system must read zero. If this does not happen, it means that there is a
mechanical problem affecting the system linearity.
Identify and correct any mechanical problems before repeating the procedure.
If theoretical full scale and recalculated full scale in Weight (Span) Calibration are equal, it means that the theoretical
calibration is currently in use; otherwise, the Weight (Span) Calibration based on test weights is in use.
If the correction made changes the previous full scale for more than 20%, all the parameters with settable weight
values are reset to default values.
Linearization Option On Max 5 Points:
It is possible to perform a linearization of the weight by performing the Weight (Span) Calibration (With Test Weights) with up to
a maximum of five points, using five different test weights. The procedure ends by pressing or after entering the fifth value.
At this point it will no longer be possible to change the calibration value; a new Weight (Span) Calibration would need to be
performed. To perform a new calibration, return to the weight display and then re-enter the calibration menu.
By pressing after having confirmed the test weight that has been set, the full scale displays the value of the maximum test
weight entered and references the cell sensitivity set in the theoretical calibration ().
IMPORTANT
IMPORTANT
Note

SCT-20 Series
14 Visit our website www.RiceLake.com
2.1.7 Setting Units of Measure
1. Press and hold , then press .  is displayed.
2. Press ,  is displayed.
3. Press or until  is displayed. Press .
4. Press or until desired unit is displayed. Press .
5. Press twice to exit set-up menu.
If the print function is enabled, the symbol of the selected unit of measure will be printed after the measured value.
2.1.8 Display Coefficient
By setting the coefficient, the display is changed accordingly.
If one of the inputs is set to  mode (Section 2.10 on page 24) when the input is closed the value displayed will be
modified according to the coefficient. When the input is opened the standard weight display will be restored.
1. Press and hold , then press to enter set-up menu,  will be displayed.
2. Press ,  is displayed.
3. Press or until  is displayed. Press .
4. Press or until desired number is displayed. Press .
5. Press twice to exit set-up menu.
Unit Display Description
 Kilograms
 Grams
 Tons*
 Pounds
 Newtons*
 Liters*
 Bars*
 Atmospheres*
 Pieces*
 Newton meters*
 Kilogram meters*
 Other generic units of measure not included on the list*
* Indicates it is possible to set the display coefficient. To use  it is
necessary to enable it, closing the  input. See Section 2.1.8.
Table 2-3. Units of Measure
Display Definition Display Coefficient
 pounds The value set in  will be multiplied by the weight value currently displayed.
 newton The value set in  will be multiplied by the weight value currently displayed.
 litres In  set the specific weight in kg/l, assuming that the system is calibrated in kg.
 bar The value set in  will be multiplied by the weight value currently displayed.
 atmospheres The value set in  will be multiplied by the weight value currently displayed.
 pieces In  set the weight of one piece.
 newton meters The value set in  will be multiplied by the weight value currently displayed.
 kilogram meters The value set in  will be multiplied by the weight value currently displayed.
 other units of measure not included list The value set in  will be multiplied by the weight value currently displayed.
Table 2-4. Display Coefficient
Note

Configuration
© Rice Lake Weighing Systems ● All Rights Reserved 15
All other settings are expressed in weight value. To convert them to the new unit of measurement, perform a
Theoretical Calibration For Other Units Of Measure on page 15 or a Weight (Span) Calibration For Other Units Of
Measure on page 15 to change the system calibration. The parameter  must remain set to 1.0000.
Theoretical Calibration For Other Units Of Measure
Set in the parameter the value divided by the conversion coefficient from kg to the new unit of measure.
Example: The 4 load cells of 1000 kg are placed under a scale for olive oil, which has a specific gravity of 0.916 kg / l. Setting
the
 = (4x1000) / 0916 = 4367, the system works in liters of olive oil. See Section 2.1.7 on page 14.
Weight (Span) Calibration For Other Units Of Measure
Load a known quantity of product litres on the scale (use as high a percentage of the maximum quantity to be weighed as
possible) and enter in the parameter
 , the product loaded value in litres. See Section 2.1.7 on page 14.
2.2 Filter On The Weight
The filtering selection is used to eliminate environment noise, and is typically a compromise between responsiveness and
stability. The lower the number, the more responsive the display will be to weight changes. The filter is used to stabilize a weight
as long as the variations are smaller than the corresponding Response Time. The filter setting is dependent on the type of
application and the required update rate (see Table 2-5 ).
Setting the parameter allows a stable weight display to be obtained. To increase the effect (weight more stable), increase value.
1. Press and hold , then press .  is displayed.
2. Press or until  is displayed.
3. Press . The currently programmed filter value is displayed.
4. Press or until desired filter value is displayed.
5. Press to accept. The current weight will then display with all LEDs scrolling and the displayed stability can be
verified.
• If the stability is not satisfactory, press twice. This returns the indicator to the  option and the filter may
be modified again until an optimum result is achieved.
• If the stability is satisfactory, press . Do not proceed until  is displayed.
• Press once to set the anti-peak filter.
The anti-peak filter can only be set after the instrument is connected to a load cell. When the weight is stable, the
anti-peak filter removes sudden weight fluctuations determined by the configured time (see Table 2-5 ), up to a
maximum duration of one second.
6. Press or to display  or to set this filter on or off
7. Press to accept.  is displayed.
8. Press to exit setup menu.
Filter Value Response Time [ms] Display and Serial Port Refresh Frequency [Hz]
0 12 300
1 150 100
2 260 50
3 425 25
4* 850 12.5
5 1700 12.5
6 2500 12.5
7 4000 10
8 6000 10
9 7000 5
Anti-peak 6 600
* Indicates default value.
Table 2-5. Filter Values
IMPORTANT
Note

SCT-20 Series
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2.3 Zero Parameters
1. Press and hold , then press .  is displayed.
2. Press or until  is displayed. Press .
3. Press or until desired parameter is displayed. See Table 2-6 .
4. Press . The currently programmed value is displayed.
5. Press or until desired value is displayed. Press to accept.
6. Press twice to exit set-up menu.
2.4 Serial Communication Settings
Figure 2-3. Serial Communications Menu Structure
Parameter Options Description
 0-max full scale
 *
Considered decimals: 300
– 30.0 – 3.00 – 0.300
Maximum zero range
Indicates the maximum weight value that can be zeroed off by external contact, keypad or serial
protocol
 0 - max 20% of full scale
 *
Automatically zeros the scale at power-on
If the weight value is lower than the value set in this parameter, the scale will zero itself provided
the weight does not exceed the value in the 0 SET parameter. To disable this function set to 0.
  *
1-5
Zero tracking
Automatically zeros the scale when within the range specified, as long as the weight is within the 0
SET parameter and the scale is at standstill for at least one second.
To disable this function, set to none.
Example: if the parameter
 is set to 5 and  is set to 2, the weight will be
automatically set to zero for variations smaller than or equal to 10 (
 ).
* Indicates default value.
Table 2-6. Zero Parameters
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