Abstract: A system is described for transmitting data in a serial bidirectional bus with a control device (1) comprising a send and receiving unit (34) for data fields (7, 8 and 9) combined into a data frame (6), and with bus subscribers (2, 3 and 4) which comprise an evaluation circuit (10) for reading in and reading out data fields (7, 8, 9, 14, 15 or 16) in data frames (6, 11), with at least the bus subscriber (4) at the bus end opposite of the control device (1) comprising a send device (12) for a data frame (11). In order to provide simple constructional conditions it is proposed that at least the bus subscriber (4) at the end of the bus comprises a control stage (13) which is activated by a received data frame (6) and triggers the send device (12) depending on the receipt of a data frame (6) within the terms of the transmission of a data frame (11) for at least the data fields (14, 15 and 16) of the bus subscribers (2, 3 and 4).

Abstract: In order to utilize the bandwidth available in the non-safe network for sending safe data in the best possible manner, it is provided for the safe data on the transmitter side to be combined by a network protocol-dependent transmitter optimization device in a network message or divided among several network messages and transmitted via the non-safe network. On the receiver side the safe data are extracted or combined again from the network protocol-specific data packets by a network protocol-dependent receiver optimization device.

Abstract: A method is proposed for braking a synchronous machine 1, with the armature windings (u, v, w) of the synchronous machine 1 being short-circuited, optionally by interposing at least one braking resistor. In order to keep the braking moment constant over virtually the entire speed range it is proposed that the short-circuit current is regulated by a pulse-width modulation depending on the difference between the setpoint value of the short-circuit current corresponding to the setpoint value of the braking moment and the actual value of the short-circuit current.

Abstract: A control panel is shown with at least one switch (12) whose actuating button (6) is situated in an opening (3) of a front panel (4), and with a housing (1) arranged in the region of the opening (3) of the front panel (4) and enclosing the switch (12), which housing forms between an inner and an outer circumferential wall (2, 5) an annular gap (8) for receiving at least one lighting means (11), which annular gap is open towards the front panel (3) and is covered in a light-transmitting manner. In order to provide advantageous constructional conditions it is proposed that that the housing (1) is inserted with its outer circumferential wall (2) in a flush manner into the opening (3) of the front panel (4) and encloses the actuating button (6) with its inner circumferential wall (5), and that the light-transmitting cover of the annular gap (8) between inner and outer circumferential wall (2, 5) consists of a foil (9) extending over the front panel (4).

Abstract: A method is proposed for braking a synchronous machine 1, with the armature windings (u, v, w) of the synchronous machine 1 being short-circuited, optionally by interposing at least one braking resistor. In order to keep the braking moment constant over virtually the entire speed range it is proposed that the short-circuit current is regulated by a pulse-width modulation depending on the difference between the setpoint value of the short-circuit current corresponding to the setpoint value of the braking moment and the actual value of the short-circuit current.

Abstract: A control panel is shown with at least one switch (12) whose actuating button (6) is situated in an opening (3) of a front panel (4), and with a housing (1) arranged in the region of the opening (3) of the front panel (4) and enclosing the switch (12), which housing forms between an inner and an outer circumferential wall (2, 5) an annular gap (8) for receiving at least one lighting means (11), which annular gap is open towards the front panel (3) and is covered in a light-transmitting manner. In order to provide advantageous constructional conditions it is proposed that that the housing (1) is inserted with its outer circumferential wall (2) in a flush manner into the opening (3) of the front panel (4) and encloses the actuating button (6) with its inner circumferential wall (5), and that the light-transmitting cover of the annular gap (8) between inner and outer circumferential wall (2, 5) consists of a foil (9) extending over the front panel (4).

Abstract: A system is described for transmitting data in a serial bidirectional bus with a control device (1) comprising a send and receiving unit (34) for data fields (7, 8 and 9) combined into a data frame (6), and with bus subscribers (2, 3 and 4) which comprise an evaluation circuit (10) for reading in and reading out data fields (7, 8, 9, 14, 15 or 16) in data frames (6, 11), with at least the bus subscriber (4) at the bus end opposite of the control device (1) comprising a send device (12) for a data frame (11). In order to provide simple constructional conditions it is proposed that at least the bus subscriber (4) at the end of the bus comprises a control stage (13) which is activated by a received data frame (6) and triggers the send device (12) depending on the receipt of a data frame (6) within the terms of the transmission of a data frame (11) for at least the data fields (14, 15 and 16) of the bus subscribers (2, 3 and 4).

Abstract: A switchboard or a display board for an electric monitoring and control system is comprised of at least two modular elements, the modular elements having visible sides of the same regular contour or of a multiple of said regular contour, the visible sides of the modular elements abutting each other to form a continuous pattern constituting a visible side of the switchboard or display board. Each modular element comprises a surface element forming the visible side and side walls projecting backwards from the surface element, the surface element having edge portions projecting outwards of the side wall and forming a peripheral region, the edge portions having outer edges with mating tongue and groove profiles whereby abutting surface elements of the modular elements may be plugged together while leaving gaps between adjacent ones of the side walls below the projecting edge portions, and the side walls being formed with undercut locking grooves.

Abstract: In an electrical system consisting of individual subassemblies, particularly in a control system composed of modules, the individual subassemblies (1, 2) comprise housings, which are adapted to be arranged in a row and for making electric line connections are provided with plug terminals for counterplug terminals on a subassembly carrier. The housings (1, 2) are secured to the subassembly carrier (4) by detachable retaining elements (27, 30, 34), particularly by swivel holders Which permit the housings to be swung up, and by snap holders (27, 28) for locking the housings when they have been swung into the row.