Terminal bus extension

Terminal bus extension

The Bus Couplers and Bus Terminal Controllers link the bus systems to the modular, extendable electronic terminal blocks. One unit consists of one Bus Coupler, any number of terminals between 1 and 64, and a bus end terminal. The “Economy plus“ and “Compact“ series support all Bus Terminals of the Beckhoff system. It is also possible to operate up to 255 Bus Terminals on this Bus Coupler series with the K-bus extension.

The Bus Terminal extension allows Bus Terminals to be located in up to 31 blocks in the control cabinet or in the application. With a distance of up to 5 m between the Bus Terminal blocks, the Bus Terminal system can be used over a wider area and helps save costs.

The Bus Coupler recognises the terminals to which it is connected, and performs the assignment of the inputs and outputs to the bytes of the process image automatically. The blocks with terminal bus extensions are treated as one unit by the Bus Coupler. The extension is transparent for the fieldbus and higher-level systems.

The system of Bus Coupler and Bus Terminal can be extended by replacing the KL9010 end terminal with the KL9020 extension. The KL9020 makes the K-bus signals available in an RJ45 socket for transmission onwards via a shielded Industrial Ethernet cable.

The KL9050 coupler terminal starts a further remote Bus Terminal block and provides the logical connection to the Bus Coupler via the Ethernet cable. 24 V DC, electrically isolated, for the field level can be input at this coupler terminal. The internal K-bus shares the same potential as the K-bus of the coupler. The KL9050 can be used via a second socket for the extension to the next Bus Terminal block. This Bus Terminal block starts in the same way as the one with a KL9050 coupler terminal. This coupling works at up to 31 stations.

The maximum distance between two Bus Terminal blocks is 5 m and allows a total extension of 155 m. The system uses shielded Industrial Ethernet cables with two RJ45 plugs for the transmission. The cable is supplied ready-made in different lengths or can be made-to-measure for applications with conventional Ethernet tools.

Data transfer is based on the interference-free and RS485 industry standard in a double-shielded cable.