Industrial Touchscreen and Large Display Integration Guide
Integrating an industrial touchscreen with a large display is a common requirement in modern manufacturing and process control environments. The goal is to have a local operator interface for control and parameter setting, while a larger screen provides a plant-wide overview of the same data. This setup enhances visibility, supports collaborative decision-making, and improves operational efficiency. Below we explore practical architectures, hardware options, software considerations, and real-world implementation tips.
Typical Use Case
A touchscreen HMI communicates with a PLC or other controller to collect data, display process variables, and allow parameter adjustments. A large monitor (e.g., 55″ or larger) mirrors the HMI screen or shows a dedicated SCADA overview, enabling supervisors and operators across the floor to monitor the process without crowding around the local panel.
System Architecture Options
There are several ways to achieve synchronized visualization between a touchscreen and a large display. The choice depends on the existing infrastructure, budget, and required functionality.
| Method | Description | Pros | Cons |
|---|---|---|---|
| Video Mirroring (HDMI/VGA Splitter) | The HMI’s display output is duplicated using a splitter or built-in secondary video port. The large display shows an exact copy of the HMI screen. | Simple, low cost, no additional software needed. | No independent control; both screens show identical content. Touch functionality only on the HMI. |
| VNC/Remote Desktop | The HMI runs a VNC server; a small PC or smart display connects as a client to view and optionally control the HMI remotely. | Allows remote access, can be wireless, supports multiple viewers. | Requires network setup, potential latency, security considerations. |
| SCADA with Web Server | A SCADA system collects data from the PLC and serves web-based screens. The touchscreen runs a thin client or browser, and the large display connects to the same web server. | Scalable, independent screen layouts, centralized data logging. | Higher cost, requires SCADA software and PC hardware. |
| Dual-Port HMI with Independent Displays | Some advanced HMIs support two video outputs with different content. One screen for operator control, another for public view. | Flexible, no extra PC needed, optimized for industrial use. | Limited to specific HMI models, higher unit cost. |
Hardware Selection
Choosing the right components is critical for reliability and performance. Consider environmental factors like temperature, dust, and vibration.
- Industrial Touchscreen HMI: Look for models with multiple communication ports (Ethernet, RS-232/485, USB) and support for protocols like Modbus TCP/RTU, EtherNet/IP, or PROFINET. Panel-mount units with IP65/IP66 front bezels are common. Examples include units with 7″ to 15″ displays, 800×480 to 1920×1080 resolution, and 24 VDC power.
- Large Display: Commercial-grade large format displays (LFDs) or industrial monitors designed for 24/7 operation. Brightness of at least 500 cd/m² is recommended for well-lit areas. Sizes range from 43″ to 75″. Ensure it has HDMI, DVI, or DisplayPort inputs. For harsh environments, consider IP-rated enclosures.
- Communication Hardware: If using VNC or web-based solutions, a reliable industrial Ethernet switch and cabling (Cat6 or fiber) are essential. For long distances, fiber optic converters may be needed.
Software and Configuration
The software side involves HMI development and possibly SCADA configuration. Most HMI programming software allows you to design screens with real-time data objects, alarms, and trends.
For video mirroring, no special software is needed—just configure the HMI’s display output. For VNC, enable the VNC server in the HMI settings and set a password. On the large display side, a small embedded PC or a smart TV with VNC viewer app can be used. Ensure the network is secure, especially if remote access is enabled.
When using a SCADA system, you can create separate displays optimized for different users. The touchscreen might show detailed control panels, while the large display shows a high-level dashboard with KPIs, alarms, and production status. SCADA packages often include web publishing features, making it easy to display screens on any browser-enabled device.
Pro Tip: Resolution and Aspect Ratio
Design your HMI screens to match the resolution of the large display if mirroring. If the large display has a different aspect ratio (e.g., 16:9 vs 4:3), you may get black bars or stretching. Some HMIs allow you to set a custom resolution to match the external monitor.
Real-World Example: Packaging Line Monitoring
A food packaging plant uses a 10″ touchscreen HMI at the machine level to control fill levels and conveyor speed. The HMI communicates with a PLC via Modbus TCP. A 55″ display mounted on the wall above the line shows the same HMI screen via an HDMI splitter. Operators can see machine status from a distance, and supervisors can quickly spot downtime events. The setup cost was minimal, using the HMI’s built-in HDMI output and a standard commercial display.
In another scenario, a water treatment facility uses a SCADA system with a web server. Local touchscreens run a web browser in kiosk mode, while a large video wall in the control room displays a custom dashboard with multiple views. This allows different departments to monitor relevant parameters simultaneously.
Key Considerations for Reliable Operation
- Network Security: If using VNC or web access, isolate the automation network from the corporate network using firewalls or VLANs. Use strong passwords and consider VPN for remote access.
- Environmental Hardening: Large displays in industrial areas may need protective enclosures against dust, moisture, and temperature extremes. Ensure adequate cooling if enclosed.
- Power Protection: Use UPS for both HMI and large display to prevent data loss and screen damage during power fluctuations.
- Maintenance Access: Design the system so that the large display can be easily serviced without interrupting the HMI operation. Consider using quick-disconnect mounts.
Future Trends
The integration of industrial touchscreens with large displays is evolving with technologies like HTML5-based HMIs, edge computing, and augmented reality. Modern HMIs can push data to cloud dashboards, allowing remote monitoring on any device. Wireless screen mirroring (e.g., Miracast) is also becoming more reliable for industrial use, reducing cabling.
By carefully selecting the architecture and components, you can build a robust visualization system that improves situational awareness and productivity on the factory floor.
