With the introduction of the new EL6861 EtherCAT Terminal, Beckhoff now supports BACnet MS/TP (Master Slave/Token Passing) in addition to BACnet/IP for building automation. This serial interface can be used to directly control and monitor BACnet-compatible field devices, such as pumps, drives, frequency converters or similar, as sub-bus systems without the need for additional gateways or routers. Up to 64 devices with RS485 low power transceivers can be connected to this I/O terminal. In addition, several terminals can be operated in parallel to scale the number of supported MS/TP channels.
Using the 1-channel BACnet MS/TP interface, hardware and engineering costs can be significantly reduced since configuration is performed centrally in the TwinCAT System Manager from Beckhoff and external devices such as routers or gateways are no longer required. Combined with the BACnet MS/TP driver integrated within TwinCAT automation software, the EL6861 terminal implements BACnet in compliance with Revision 12 of the protocol. The terminal can also be used locally without routing to the BACnet/IP network.
The RS485 interface guarantees high interference immunity through electrically isolated signal transmission. The EL6861 provides 1 x 5 V DC at 20 mA (electrically isolated, short-circuit-proof) from the EtherCAT E-bus supply for use with bias resistors (network bias).