RS485 interface certified according to EN 50131-1

The context of the solution

High-security facilities such as power plants, data centers, government buildings or military facilities require uncompromising reliability. Here, the operator typically deals with the construction of a modern IP network for video surveillance systems, but must also ensure error-free data transmission for security systems (PZTS) such as Honeywell Galaxy or Asset. Traditionally, these systems communicate via RS485 bus, which in large premises usually means that hundreds of metres of separate metallic cabling must be laid.

Solution description

By using LAN-RING industrial L2 switches, we eliminated the need for parallel wiring in this scenario. Our solution allows Galaxy and Asset system protocols to be transmitted directly over the same optical fiber used for normal data and video traffic.

Data from the RS485 bus is "wrapped" inside the switch and transmitted along with the IP traffic. The integrated RS485 ports on LAN-RING switches are fully optimized for the specific timing and communication of these particular security systems.

• VLAN separation.

• Prioritization (QoS).

Typical LAN-RING wiring diagram

Main benefits for critical infrastructure

1. Cost and risk reduction: No need to build and maintain separate metallic routes for RS485. All communication runs over durable fiber optics that are immune to electromagnetic interference and surges.

2. Certified safety: the entire solution meets the stringent requirements of EN 50131-1 levels 3 and 4. This compliance is confirmed every three years by an independent testing laboratory, a necessary standard for critical infrastructure facilities.

3. In-depth diagnostics: Unlike traditional "wired" buses, this solution enables detailed monitoring of the status of each data link in real time, reducing maintenance response time.

Conclusion

By using LAN-RING switches with RS485 ports, high-security facilities gain a highly efficient infrastructure. The Galaxy and Asset systems are fully integrated into a modern IP environment without sacrificing security or certification, making this solution a leader in the industrial communications industry.

Certification

To ensure full compliance with the requirements for systems in critical infrastructure facilities, devices have been selected to meet the most stringent security standards. The following models are fully certified to EN 50131-1 (Levels 3 and 4), guaranteeing their reliability in integration with Galaxy and Asset systems.

In the table below you will find an overview of the certified elements that enable secure data transmission:

• Industrial LAN-RING switches with integrated RS485 ports.

• Serial to fiber optic (miniLAN) converters that provide RS485 to LAN conversion.

• Optical converters (TDW and RDW) for extensive fibre optic backbones within the site.

Functional limitations

• It is recommended to connect a maximum of 30 switches in the optical rings.
• When connected to a LAN-RING system, all C080 readers on one bus must be connected at one point (to one switch).
• The switches have 2 independent RS485 ports. For Galaxy/Asset buses only one port can be used at a time. This is due to the high requirements of these systems for low latency. If you need to convert 2 or more buses to LAN at one location, use the miniLAN-4B2 modules.

Recommended configuration

• VLAN - A separate VLAN must be allocated for the RS485 bus.
• QoS - RS485 bus data must be assigned a high priority

• Installation in tamper-evident enclosures
• Backup power supply
• Monitoring of all data connections via SNMPv3