FC3102-1258 by Beckhoff

The FC3102-1258 is a dual-channel PROFIBUS communication card produced by Beckhoff within the FC Lightbus Cards series. Installed in a PCI slot of an industrial PC, the board links the control platform to remote I/O stations over the PROFIBUS fieldbus. By supporting master or slave operation on each channel, it allows the host controller to coordinate peripheral devices or participate as a subordinate node in larger distributed automation networks.

Physical integration starts with two D-Sub sockets that route both channels to the plant wiring through an RS485 transceiver stage. The board draws its logic supply directly from the backplane at 5 V, and the typical load on that rail is 1000 mA. These values help designers determine power requirements inside compact controllers. Communication with the PC takes place over a plug-and-play PCI interface; enumeration and resource assignment therefore occur automatically without manual jumper settings. Data moves across a 32-bit bus width, so process images can be transferred in double-word increments, reducing CPU cycles compared with narrower interfaces. Galvanic isolation separates field wiring from the computer ground to limit noise injection and protect electronics during fault conditions.

Each channel can accept up to 244 bytes of cyclic data from a single slave and map that traffic into a maximum process image of 3 kbytes inside the host memory. The onboard DPRAM allocates 4 kbytes per channel, ensuring sufficient buffering for telegram sequencing when network load peaks. A single link can supervise 125 addressed slaves, providing capacity for modular valve terminals, drives, and remote I/O nodes on one trunk. Two status LEDs per channel provide local diagnostics. Mixed master-and-slave operation permits network arrangements in which the Beckhoff PC controls downstream devices and forwards data upstream to higher-level controllers.