CIRCUIT ASSEMBLY FOR DATA SIGNALS TRANSFER BETWEEN CONTROLLING DEVICES MUTUALLY CONNECTED OVER RING NET SYSTEM

A method and apparatus for transmitting data between a number of control devices which are connected to each other by at least one clock-controlled loop, which is operated directionally dependent, are disclosed which cause a transmit authorization signal to be sent via the loop from control device to control device which places each control device, upon receipt thereof, in a transmit authorization status. A control device receiving the transmit authorization signal emits data signals to be transmitted via the loop, with a receiver address identifying a selected other control device intended to receive the data signals, before forwarding the transmit authorization signal to another control device. The control device which transmitted the data signal is then switched to an acknowledgement signal reception status. If the intended other control device receives the data signals correctly, it sends an acknowledgement signal to the transmitting control device. The transmitting control device is maintained in the acknowledgement signal reception status for a time no longer than arrival of a further transmit authorization signal. If the transmitting control device receives the acknowledgement signal within this time, it is then switched to a status enabling renewed emission of further data signals. If no acknowledgement signal is received within this time, the transmitting control device is switched to an error status for either reporting the error or initiating steps to correct the error.