Product Description:

The FC2002-0000 is a PCI fieldbus master card manufactured by Beckhoff within the FC Lightbus Cards series. Installed inside an automation PC, it forms the interface between the host CPU and one or two fiber-optic Lightbus rings, enabling deterministic exchange of input and output data with distributed devices on the line.

The card connects to the Lightbus network through a 4 x fiber-optic bus interface, and it hosts two independent Lightbus channels that each move telegrams at 2.5 Mbit/s. At this speed, a complete 32-bit process data word is transferred in 25 µs, which suits motion or high-speed packaging tasks. The host computer communicates across a 32-bit PCI backplane; matching the 32-bit process data width allows direct memory images of the field data. Each channel contains 4 kB per channel of dual-ported RAM that buffers cyclic data, while a ring-level memory of 512 kB per ring stores the global process map. Three diagnostics LEDs on every channel indicate operating state, link activity, and error conditions, providing at-a-glance troubleshooting without external tools. Because the board uses the Lightbus protocol exclusively, no additional fieldbus co-processor is required.

For application mapping, every channel is divided into 8 logical subdivisions, and a hardware interrupt scheme with 2 IRQs lets the driver react to ring events without polling. Up to 255 per channel remote stations can be addressed, yielding a theoretical maximum of 65280 per channel discrete I/O points before the bus saturates. System power is drawn from the backplane at 5 V, and there is no NOVRAM on the board, so all configuration parameters are loaded from the PC during startup. The absence of on-board non-volatile memory simplifies firmware maintenance while the Lightbus-specific electrical isolation on both channels keeps the fiber-optic rings independent of chassis ground.