Abstract:
The invention relates to a switching node (100) and to a method for operating a switching node (100) in a data network. Said method comprises the following steps: receipt of a data message (118) at a first port (102) of the switching node (100); verification (112) of whether the data message (118) is a broadcast data message. If said message is not a broadcast data message, the source address of the data message (118) is passed to a dynamic address table (110) and if said message is a data broadcast data message, the data message (118) is forwarded via the additional ports (104, 106, 108) of the switching node (100).
Abstract:
The invention relates to a method for transmitting real time data messages in a cyclic communications system, each transmission cycle having a first partial cycle (IRT-Z.) for the real time communication and a second partial cycle (NRT-Z.) for the non-real time communication. Said method comprises the following steps: determination (118) of a cycle number; processing of a transmission sequence of real time data messages in the first partial cycle, whereby the transmission sequence is composed of one or more partial sequences (1, 2, 3, 4, 5) and the composition depends on the cycle number.
Abstract:
The invention relates to a method for the starting up of at least one first field instrument (104), wherein the method comprises the step of signaling a first demand for electrical power output (146) of the first field instrument over a first port (120) to a supply unit (102). According to this method, the first field instrument is previously connected to the supply unit over the first port by means of a first communication connection (144). In addition, the reception of the power output is effected according to the first demand for power output by the first field instrument over the first communication connection and the first port, by which the first field instrument is activated. In an additional step, a power usage unit (124) of the first field instrument is assigned to the first port, wherein the power usage unit is provided as consumer load for the power output. In addition, the allocation of a power supply unit (126) of the first field instrument is effected to a second port (122), with the power supply unit provided for the supply of an additional second power output (152) over the second port. In a different aspect, the invention relates to a field instrument and a supply unit. The invention is particularly suited for the supply of field instruments over an Ethernet connection (power over Ethernet), wherein several inline switched Ethernet field instruments according to the invention can be supplied with electrical power by one upstream supply unit such as a PoE switch.
Abstract:
The invention relates to a method and a user (100) of a data network (102) comprising: a command unit (116) for accessing the data network (102), means for operating several applications (104, 106, 108,...), whereby said applications can access a data bus (110) of the user (100), means for writing at least one command structure (118) in an address range of a memory of the user (100) by means of a first of the applications via the data bus (110), means for writing an indicator (124) for the address range in the input register (126) of the command unit (116) by means of the first application via the data bus (110), means for enabling the command unit (116) to access the address range via the data bus (110) and to process the command structure (118) and means for writing the indicator (124) in an output register (136, 130) that is assigned to the first application, once the user (100) has processed the command structure (118).
Abstract:
The invention relates to a method for the arbitration between users (Tn1, Tn2,...) of access to a data bus, whereby the users are coupled by at least one arbitration ring (12; 38, 40, 42, 44, 46, 48). The method comprises the following steps: a) request for access of a first user; b) verification of whether a first signal that indicates the release of the arbitration ring is present at an input (16) of the first user; c) emission (18) of a second signal by the first user, if the first signal is present; d) verification of whether the first signal is still present at the input of the first user at the end of a predetermined time period; e) access by the first user, if the signal was still present at the end of the predetermined time period.
Abstract:
The invention relates to a method for receiving data messages in communications systems comprising redundant network paths. The received data of the peripheral image is routed to a node along at least two different network paths. This permits a consistent peripheral image to be stored in a memory (13) of the node, if data transmission along one network path is impaired.
Abstract:
The invention relates to a method for transmitting real time-critical data using data messages in a data network. The data messages have an identification, useful data and a transfer status. According to the inventive method, data messages comprising errors are replaced by replacement messages that have the same structure as the data messages. The replacement message has the same identification as the data message to be replaced and is thus forwarded via the switching node, which would have been used to route the error-free data message. The replacement message can contain details of the type of transmission error.