Indicators with bus interfaces (OIML)

Indicators with bus interfaces for industrial weighing systems

Indicators with bus interfaces combine weight display with the digital signal processing and communication capabilities of modern weighing systems. The devices acquire signals from connected load cells, process the measurement values and clearly display weight, status and process information via LED or LCD displays. At the same time, weighing data can be transmitted via serial interfaces or industrial bus systems to PLCs, PCs, printers or higher-level control systems.

This makes weighing indicators particularly suitable for industrial applications where weight values need not only to be displayed but also directly processed for control, monitoring or dosing tasks. Depending on the model, RS232 and RS485 as well as bus interfaces such as Profibus DP, DeviceNet, CANopen, Profinet IO, EtherNet/IP, Ethernet TCP/IP or Modbus/TCP are available.

For different installation and environmental conditions, Althen offers compact panel-mount indicators as well as robust desktop, wall-mounted and stand-alone units. Versions with protected plastic or stainless-steel housings are also suitable for use in wet, dusty or hygienically demanding production environments.

Flexible solutions for weighing, control and connectivity

Althen indicators with bus interfaces combine precise weight measurement with user-friendly operation and flexible communication. Depending on the application, different display sizes, housing versions, protection ratings, inputs and outputs, and communication interfaces are available.

In addition to displaying weight, the devices can – depending on the model – perform additional functions such as limit monitoring, relay control, calibration, linearization or dosing. OIML-approved versions are also available for applications subject to legal requirements for weighing technology.

What to consider when selecting an indicator with bus interface

1. Define the weighing task and required functions
The first step is to determine which task the indicator needs to perform. A simple weight display has different requirements from applications involving dosing, filling, discharge, recipe management or automated process control.

2. Select the appropriate bus interface
The indicator should connect to the existing automation system without unnecessary integration effort. Depending on the model, interfaces such as RS232, RS485, Modbus RTU, Profibus DP, CANopen, DeviceNet, Profinet IO, EtherNet/IP, Ethernet TCP/IP or Modbus/TCP are available.

3. Consider the number and type of load cells
Check how many load cells will be connected to the indicator and which electrical characteristics they have. The supply voltage and input sensitivity must also match the weighing system.

4. Check OIML requirements
For legal-for-trade or legally regulated weighing applications, the appropriate approval is essential. Depending on the device, OIML-compliant versions are available. The specific approval should always be verified for the selected model and intended application.

5. Select the display and operation to suit the application
LED displays provide excellent readability of weight values, while graphical LCD displays can show additional information and more complex user interfaces. Digit height, backlighting, keypad design and signalling LEDs should also be considered during selection.

6. Consider the protection rating and housing
For installation in a protected control cabinet, a panel-mount indicator is often sufficient. Wet, dusty or regularly cleaned environments require robust housings with a higher IP protection rating. Stainless-steel versions are also available for hygienically demanding applications.

7. Define inputs and outputs for process control
Logic inputs and relay outputs can be used, for example, to control limit values, valves, signal lights or other process components. In automated weighing and dosing processes, the required number and functionality of these inputs and outputs should be considered at an early stage.

8. Consider calibration and commissioning
Many devices allow theoretical calibration directly via the operating keys. Depending on the model, real calibration with multi-point linearization is also possible. This makes it easier to adapt the weighing system to the specific application.

Our technical expert team will be happy to support you in selecting the right weighing indicator, interfaces and functions for your weighing system. Go to the contact form

Typical applications of indicators with bus interfaces

Digital weighing indicators with bus interfaces are used wherever weight data must be displayed reliably and simultaneously transmitted to industrial control and automation systems.

Typical applications include:

• Industrial weighing systems and platform scales
• Tank, vessel and silo weighing
• Dosing, filling and discharge processes
• Filling and packaging systems
• Process monitoring and plant control
• Production and material flow control
• Food and packaging industry
• Hygienic weighing and dosing applications
• Mechanical and plant engineering
• Automated production systems

Thanks to different designs, protection ratings and communication interfaces, the weighing indicators can be flexibly adapted to the specific measurement and automation task.