Siemens 6ES5777-0BC00 – Bus Terminal for SINEC L2 Network Connections

The Siemens 6ES5777-0BC00 terminates both ends of a SINEC L2 fieldbus segment. This bus terminal measures 95 mm in height and 22 mm in width. It has a depth of 55 mm, so it fits on DIN rails easily. The unit weighs 0.08 kg, making installation quick and effortless.

Termination Function and Network Integration

This bus terminal provides active termination for impedance matching on L2 networks. The Siemens 6ES5777-0BC00 installs at the physical start and end of each bus segment. It prevents signal reflections that cause communication errors on long cables. The terminal includes a switch for enabling or disabling termination as needed. An integrated LED shows when the termination circuit is active.

Internal Circuitry and Component Layout

The terminal contains one small circuit board inside its plastic housing. The Siemens 6ES5777-0BC00 uses precision resistors to match the cable’s characteristic impedance. It includes a 220 ohm termination resistor and biasing network for signal stability. The module stores no capacitance or energy storage components at all. It requires no external power supply for any termination function.

Connection Interface and Installation Details

You will find two 9-pin D-sub connectors on this bus terminal for daisy-chaining. The Siemens 6ES5777-0BC00 connects inline between the cable and the last device. Screw terminals on the side accept the incoming and outgoing cable shields. The unit mounts on standard 35 mm DIN rails inside control cabinets. A grounding screw provides a direct connection to protective earth.

Environmental Specifications and Mechanical Design

The Siemens 6ES5777-0BC00 operates reliably from 0°C to 60°C ambient temperature. It tolerates humidity levels up to 95 percent without any condensation issues. The terminal has an IP20 rating for indoor installation in protected areas. A transparent cover allows easy viewing of the status LED at all times. The compact housing saves valuable space inside crowded control cabinets.

Below is a complete summary of its technical specifications.

The Siemens 6ES5777-0BC00 replaces older terminating plugs in SINEC L2 networks. You must install this terminal at both ends of each bus segment. This device prevents data corruption caused by signal reflections on long cables. Consequently, it ensures reliable communication for distributed S5 I/O systems.