ABB AC 800M

RLM 01 - Redundancy Link Module Section 3 Fieldbus Topologies
92 3BDS009029R5001 B
RLM 01 - Redundancy Link Module
The Redundancy Link Module RLM 01 converts two reciprocally redundant
PROFIBUS DP/FMS lines into simple, non-redundant A/B lines and vice versa. The
module works bidirectionally. It transmits and receives in parallel over both lines.
The first incoming plausible data are routed to the output.
RLM01 features:
• Use on PROFIBUS-DP/FMS lines
•
Conversion of a non-red. PROFIBUS line into two redundant lines and vice versa
• Automatic line selection
• Transmission rate 9.6 kbit/s – 12 Mbit/s
• Monitoring of the communication
• Repeater functionality
• Redundant power supply connection
• Status and error display via LED
• Alarm contact
Figure 35. RLM 01 - Redundancy Link Module
The RLM 01 can also be set to support line redundancy for a master with non-
redundant PROFIBUS output.
RLM01 does not support master redundancy where one master only runs line A
and the other one only line B. The bus communication is asynchronous, even if
both masters are balanced with respect to each other on the program level.