Transmitting module for a transmitting/receiving device of a subscriber station of a serial bus system and method for transmitting a message with differential signals in a serial bus system

A transmitting/receiving device for a subscriber station of a serial bus system, comprising:

• a transmitting module configured to transmit a digital transmit signal as an analog differential signal to a bus of the bus system to transmit a message to at least one other subscriber station of the bus system, the transmitting module including:
• transmission stages with parallel circuits including switchable resistors, and
• a control part configured for step-by-step control of switching of the switchable resistors;
• wherein at least two of the switchable resistors are arranged so as to be switchable together in a resistor block,
• wherein at least two resistor blocks are provided which have at least one of the switchable resistors, and
• wherein the control part is configured to generate bus states predetermined by the digital transmit signal over time on the bus by step-by-step changing a number of actively switched resistor blocks over time;
• and
• a receiving module configured to receive signals from the bus and to generate a digital reception signal from the analog differential signal.

A subscriber station for a serial bus system, comprising:

• a transmitting/receiving device, including:
• a transmitting module configured to transmit a digital transmit signal as an analog differential signal to a bus of the bus system to transmit a message to at least one other subscriber station of the bus system, the transmitting module including:
• transmission stages with parallel circuits including switchable resistors, and
• a control part configured for step-by-step control of switching of the switchable resistors;
• wherein at least two of the switchable resistors are arranged so as to be switchable together in a resistor block,
• wherein at least two resistor blocks are provided which have at least one of the switchable resistors, and
• wherein the control part is configured to generate bus states predetermined by the digital transmit signal over time on the bus by step-by-step changing a number of actively switched resistor blocks over time, and
• a receiving module configured to receive signals from the bus and to generate a digital reception signal from the analog differential signal, and
• a communication control device configured to control communication in the bus system and to generate a first transmit signal;
• wherein the subscriber station is configured for communication in a bus system in which an exclusive, collision-free access of a subscriber station to a bus of the bus system is guaranteed at least temporarily.

A method for transmitting a message with differential signals in a serial bus system, wherein the method is carried out using a transmitting module which has transmission stages with parallel circuits including of switchable resistors and is configured to transmit a digital transmit signal as an analog differential signal to a bus of the bus system to transmit a message to at least one other subscriber station of the bus system, the method comprising:

• controlling, step-by-step, switching of the switchable resistors with using a control part of the transmitting module,
• wherein at least two of the switchable resistors are arranged so as to be switchable together in a resistor block,
• wherein at least two resistor blocks are provided which have at least one of the switchable resistors, and
• wherein the control part generates bus states predetermined by the digital transmit signal over time on the bus by step-by-step changing a number of actively switched resistor blocks over time.