1. Introduction
In today's industrial environment, legacy operator interfaces (HMIs) are becoming a critical bottleneck. Proprietary systems developed decades ago limit the integration with modern network protocols such as OPC UA or MQTT, which are necessary for the implementation of Industry 4.0 principles. Outdated hardware increases the risks of unplanned downtime due to a shortage of spare parts and the inability to update software. According to energy efficiency requirements and safety standards such as EN 60204-1, modernization of the control system is a necessary step to maintain the competitiveness of the enterprise.
2. Evaluation of outdated systems
Before making a decision on replacement, it is necessary to assess the technical condition of the existing equipment.
| Evaluation criteria | Risk indicator | Impact on production |
|---|---|---|
| Availability of spare parts | Low (discontinued) | High risk of prolonged downtime |
| PLC compatibility | Limited (legacy protocols) | Inability to expand automation |
| Cyber security | There is no support for updates | Risk of external interference |
| Energy consumption | High (legacy displays) | Increased operating costs |
3. Modern alternatives
The transition to open standards allows unifying the management architecture. As an example of modernization, consider the use of Danfoss panels 9051678.
| Characteristics | Outdated system | Danfoss 9051678 |
|---|---|---|
| Protocols | Proprietary | Support PROFINET, Ethernet/IP, Modbus TCP |
| Display | Resistive, low resolution | Projection-capacitive, high definition |
| Reliability (MTBF) | 25,000 hours | > 50,000 hours |
| Compliance | Outdated standards | CE, UL, meets strict safety standards |
4. Calculation of return (ROI)
Consider the case of upgrading a production line with 5 HMI panels.
- Cost of modernization (equipment + engineering works): 15,000 EUR.
- Average downtime due to legacy HMI failure: 4 hours per month.
- The cost of an hour of downtime: EUR 2,500.
- Annual losses from downtime: 4 * 12 * 2,500 = 120,000 EUR.
- Expected downtime reduction after replacement: 90%.
- Annual savings: 108,000 EUR.
- Payback period: less than 2 months.
Energy savings and reduced maintenance costs provide an additional positive economic effect.
5. Implementation roadmap
To minimize the impact on the production process, a step-by-step approach is used:
- Planning and auditing: Compilation of a complete list of signals and integration points.
- Preparation: Setting up Danfoss 9051678 in laboratory conditions.
- Logging: Implementation on one, non-critical section of the line.
- Full migration: Installation and commissioning during planned PPR (planned preventive maintenance).
6. Technical challenges
The main difficulty lies in transferring logic from proprietary software to open standards. To solve this problem, we use intermediate data gateways and automatic tag conversion tools. It is important to ensure full compatibility with existing PLCs, which is achieved by using standard communication drivers.
7. Example (Case Study)
At a polymer processing plant, replacing 10 legacy HMIs with Danfoss 9051678 reduced operator response time to critical emergency messages by 40% and eliminated 100% of downtime due to legacy display failures. MTBF increased from 18,000 to 55,000 hours.
8. Commissioning and testing
After installation is carried out:
- Testing communication with the PLC (validation of tags).
- Checking emergency signals (error simulation).
- Security testing (checking user access levels).
- The final protocol of acceptance in accordance with the requirements of internal quality standards.
Summary
HMI modernization is not just replacing hardware, it is a strategic step to ensure stability and compliance with modern security standards. UNITEC-D GmbH provides both the supply of the components themselves and full technical support for the migration process. Check out the available retrofit solutions in our UNITEC-D E-Catalog.
References
- EN 60204-1: Machine safety. Electrical equipment of machines.
- ISO 9241: Ergonomics of human-system interaction.
- EU Directive 2009/125/EC (Ecodesign).
