The interlocking computer generates reversing commands for the point machines in the outdoor installation. The BÄR OC PM uses these commands to control the connected points and permanently monitors their position (end position left, end position right or undefined intermediate position). The connection to the points is monitored by an EFM earth fault detection system.
The data connection to the interlocking computer is made via a redundant, secure Ethernet bus connection FSE-FSX. Interruptions in the connection of each of the two bus connections to the interlocking computer are detected by the BÄR OC PM. In the event of a single interruption, the full function of the card is retained. If both bus connections are interrupted, no defined end position can be reported to the central computer.
Point-specific information such as network configurations and safety parameters are programmed in a backplane configuration plug. When the interface card is plugged in or the system is started up, the data is read from the configuration.
A single BÄR OC PM includes up to six interface cards (IPM). It can, therefore, individually control and monitor up to six points. The IPM backplane is mounted on the rear of the 19” card rack. It serves as the interface for the connections of analogue feeds to and from the turnout interface cards. On the left side of the backplane there is the feed with the input fuses from the power supply, whereby each turnout drive is assigned its own fuse. On the left side of the fuses are the outgoing connectors of the turnout cables to the cable termination rack. The configuration data of the turnouts are located on the backplane. For this reason, the backplane must not be switched.
The circuits of the points are galvanically isolated from the other interlocking circuits. If earth faults occur in the outdoor installation due to external influences, such as flooding, insulation defects or damage, these are detected by the earth fault detection and reported to the interlocking computer. In case of a single earth fault, the full interlocking function is maintained.