ProfiHub B4FO2+ optický MM coupler PROFIBUS

ProfiHub B4FO2+ - Fiber Optic to Multi Segment Coupler

The B4FO2+ supports multiple fiber optic topologies; point-to-point, bus and star. The protocol transparency without configuration, allows direct integration in existing PROFIBUS networks to benefit from the advantages optical data infrastructures offer. The ProfiHub B4FO2+ is equipped with 4 galvanic isolated RS 485 channels utilizing a maximum of 31 devices per channel. The mechanical design consists of a compact, flat and stable metal housing which can be mounted on a DIN-rail. It contains an alarm relay, redundant power supply, diagnostic LEDs and it supports the redundancy feature.

The ProfiHub B4FO2+ is suitable for use when creating PROFIBUS DP optical networks because it allows you to create point-to-point, star or tree topologies. If you are going to build an optical network on PROFIBUS or reconstruct an existing optical network, then you probably need classic OLMs anyway. Consider using a ProfiHub product to achieve multiple network topology variations, increase robustness in the metallic segment behind the optics, and also automatically get a measurement point for each metallic segment.

Main advantages

• Create up to 2 galvanically separated metallic segments behind the fiber.
• You can create a point-to-point, star or tree topology.
• Allows redundant power supply with alarm relay contact in case of secondary power failure.
• Installation does not require a change in the PB Master station's HW configuration.
• The CANON measurement port on each metallic segment allows you to connect a PB tester and measure each segment separately.
• LEDs inform about the communication status (OK, ERROR) on each channel.
• You can set a specific PB speed (protection against unwanted network speed reduction in the PB Master station, the ProfiHub will not allow any speed other than the set speed).
  
  
  

Perfect galvanic separation of all PROFIBUS segments

The advanced electronics of the ProfiHub multirepeater allows (unlike competing repeaters) unlimited cascading in succession (i.e. a maximum of 9 repeaters in a cascade does not apply).

The ProfiHub has 100% short circuit protection, i.e. if you short the A/B wires in segment 1 with respect to each other, this short circuit will not pass to the other segments. This behavior is logically expected from a repeater, but unfortunately does not apply to many other repeaters on the market.

In addition, the data on the network is constantly monitored for the presence of skew, which ProfiHub digitally smoothes out. We know from our customers that they prefer ProfiHub multirepeaters precisely because of the better galvanic separation of all segments, which has minimized outages on PROFIBUS networks. 

Prefer less PROFIBUS stations per segment

In our experience, we recommend that customers do not have up to 31 PROFIBUS stations per segment, because 31 stations means 31 potential causes of problems that can cause signal reflections in the PROFIBUS cable. This reflection increases with the length of the segment and eventually becomes so large that it usually shuts down the farthest station.

We therefore recommend our customers to deploy e.g. a maximum of 5-10 PROFIBUS stations in one segment. In practice, this means that you bring the signal from the MASTER station into the ProfiHub multirepeater (you can then continue further) and connect a maximum of 5-10 stations per segment. These can be stations always in one rack, stations in one direction from the rack, all inverters / IO peripherals / HMI panels etc. It doesn't really matter because ProfiHub acts as a hub, so it connects everything to everything. It's virtually irrelevant what stations you connect to each channel (segment).

This strategy of dividing the network into smaller segments with fewer stations not only significantly increases the robustness of the PROFIBUS network, but in the event of a problem with the PROFIBUS network, it also reduces the time it takes to find the cause of the error, since the cause and effect can usually only be found in one segment.