ABB RLM02 Redundancy Link Module

Field devices equipped with a single PROFIBUS DP interface can be integrated into a redundant PROFIBUS network using the Redundancy Link Module (RLM02). Acting as an active switch, the RLM02 converts two redundant lines into one PROFIBUS DP line or vice versa. It amplifies the signal form and amplitude of incoming data and monitors the activity and error status of all three lines.

RLM02 at a Glance

• Three PROFIBUS Ports: Supports conversion between one and two PROFIBUS lines.

• Transparent Configuration: No slave address required; transparent to PROFIBUS configuration.

• Transmission Rates: Supports from 9.6 kbit/s up to 12 Mbit/s.

• Client Support: Serves up to 31 PROFIBUS clients; extendable with repeaters (optical-electrical).

• Error Indication: Errors signaled via an LED on the front panel and a signaling contact.

• Diagnostics: Specific diagnostic messages available via the 8-pin terminal strip.

• Certifications: CE, UL, CSA certified; holds Type Approval Certificate “DNV GL” for marine applications.

Key Functions and Features

• Converts one simple, non-redundant PROFIBUS line into two reciprocally redundant lines (A/B) and vice versa.

• Suitable for use on PROFIBUS DP/FMS lines.

• Automatic line selection for seamless operation.

• Communication monitoring and repeater functionality to enhance signal integrity.

• Wire cross-section: 8-pin terminal strip, supports up to 1.5 mm².

• Redundant power supply: 24 VDC (+20 V to +33 V), typical current 120 mA at 24 V.

• Operating temperature range: 0°C to 50°C.

• Status and error display for quick diagnostics.

• Power supply monitoring to ensure system reliability.

• Potential-free signaling contact for external error indication.

• Easy installation on standard DIN mounting rails.