Laumas TLM8 weighing transmitter

Laumas W series weight display (via dedicated protocol)

PC or PLC (as Modbus slave)

Remote monitor, printer, inclinometer (via RS485)

Special feature: RS485 and RS232 can be directly connected without the need for a level converter, simplifying integration with older serial devices.

7.2 Fieldbus Integration

When selecting models with bus suffixes, TLM8 can serve as a slave/adapter/device for the following networks:

PROFIBUS DP: Standard industrial fieldbus widely used in PLC systems such as Siemens.

EtherCAT: High speed real-time Ethernet, suitable for motion control and high-speed weighing.

EtherNet/IP and PROFINET IO: used respectively for industrial Ethernet environments of brands such as Rockwell and Siemens.

CC Link: Mitsubishi Electric led fieldbus, commonly seen in Asia.

CANopen/DeviceNet: Suitable for in vehicle or distributed I/O systems.

Modbus/TCP: a universal Ethernet protocol that can communicate directly with SCADA.

Ethernet TCP/IP: Supports WEB APP integration software, which can be remotely monitored, configured, and diagnosed through a browser without the need to install a client.

7.3 Data content transmitted through the bus

Through fieldbus or RS485 (Modbus RTU), TLM8 can provide:

The raw millivolt signal value of each channel (unfiltered calculated value) - for PLC to perform weight calculation (zero point, tare weight, linearization) on its own.

The percentage of load distribution for each channel (% of total).

Total weight, weight of each channel (calibrated internally).

Relay output status and digital input status.

Diagnostic results (abnormal sensor indicators).

The status of the ingredient program (feeding in progress, completed, out of tolerance, etc.).

This flexible data granularity makes TLM8 not only an independent weighing instrument, but also an intelligent weighing sensor front-end that can implement complex algorithms in high-end PLCs or PCs.

Suggestions for Installation and Configuration Practice

8.1 Installation precautions

Power supply: TLM8 requires a stable 24V DC power supply. It is recommended to install an isolated power supply or filter to avoid coupling with interference sources such as frequency converters.

Sensor wiring: Use qualified 6-wire (with sense) or 4-wire weighing cables, with the shielding layer grounded at a single point on the instrument end. Each channel is independently wired to avoid mutual interference.

Relay output: When controlling AC contactors, RC absorption circuits or varistors must be connected in parallel at both ends of the coil to prevent reverse electromotive force from damaging the contacts.

Digital input: When external passive contacts or NPN/PNP signals are connected, please note that TLM8 is PNP type (high level effective), with the common terminal connected to 0V.

8.2 Configuring with Instrument Manager software

Recommend using the free Instrument Manager software provided by Laumas for initial setup:

Connect the USB-RS485 converter of the PC to the RS485 port of TLM8.

Scan the device and select the corresponding model.

Set the sensor parameters for each channel (sensitivity mV/V, range, etc.).

Perform digital balancing: Enter the mechanical position and weight of each channel in sequence according to the software wizard.

Configure analog output, relay settings, bus communication parameters (station address, baud rate, etc.).

8.3 Typical problem troubleshooting during on-site debugging

Possible causes and solutions for the phenomenon

A certain channel displays "abnormal" or no weight change. If the sensor is disconnected, has poor contact, or is damaged, enter the "Load Unit Input Test" menu to check if the mV signal of the channel is normal; Check the wiring terminals

Unstable total weight, large mechanical vibration, low filtering coefficient, and poor grounding increase the depth of digital filtering; Check the shielding grounding; Enable 'Stable Weight Condition' in the software

Bus communication failure with inconsistent baud rate, checksum, and station address; The terminal resistance has not been confirmed to be consistent with the parameters of TLM8 and the main station; Add 120 Ω terminal resistors at the beginning and end of RS485

Frequent ingredient deviation and inaccurate drop setting, as well as automatic drop learning function enabled for changes in material fluidity; Adjust the fast/slow add switching point

After calibration, the weighing non-linear sensor itself is non-linear or unevenly loaded during installation, and 8-point linearization calibration is used; Check the installation level of the sensor and rebalance it if necessary

Examples of application scenarios

Large tank weighing (3-8 support points)

Connect each sensor using TLM8 and output the total weight to PLC (PROFIBUS or EtherNet/IP) after digital balancing. At the same time, use the load distribution map to monitor whether each support point is empty.

Multi component batching system

Each TLM8 controls 1-2 sensors at a batching station, independently completing batch feeding using the built-in single product batching program. The PLC is only responsible for starting and collecting completion signals, greatly simplifying the program.