An industrial control I/O module for interfacing with industrial control equipment, such as sensors and actuators, can be configured to dynamically provide differing resistances in each channel as may be required for reliably achieving particular modes of operation in the channel. Providing differing resistances in such channels flexibly allows different modes in the channel to provide universal I/O capability. Modes of operation could include, for example, digital output, digital input, analog output, analog input and the like, in the same channel, but at different times. In one aspect, a processor or voltage divider can be used to control an amplifier, with feedback, driving a transistor in a channel to dynamically adjust resistance in the channel by selectively biasing the transistor to achieve a resistance in the channel suitable for the selected mode.

An input module may include a first resistor and a second resistor coupled in series with the first resistor. The input module may also include a switch that may electrically isolate the second resistor based on a voltage output by an additional input module electrically coupled to the input module via a terminal base.

At least two redundant analog input units for a measurement current have analog inputs which are connected in parallel and upon which voltage measuring devices directly lie to convert respectively applied voltages into a digital measurement value, wherein in order to detect errors, in particular in order to detect wire breakage, each analog input unit compares its generated measurement value with a threshold and outputs an error message if a measurement value is detected that falls below the threshold, where if the analog input of the analog input unit is in the low-resistance state, then the at least one other analog input unit is additionally caused to assume a current-measuring function and switch the analog input of the analog input unit to a low-resistance state.

At least two redundant analog input units for a measurement current have analog inputs which are connected in parallel and upon which voltage measuring devices directly lie to convert respectively applied voltages into a digital measurement value, wherein in order to detect errors, in particular in order to detect wire breakage, each analog input unit compares its generated measurement value with a threshold and outputs an error message if a measurement value is detected that falls below the threshold, where if the analog input of the analog input unit is in the low-resistance state, then the at least one other analog input unit is additionally caused to assume a current-measuring function and switch the analog input of the analog input unit to a low-resistance state.

An input module may include a first resistor and a second resistor coupled in series with the first resistor. The input module may also include a switch that may electrically isolate the second resistor based on a voltage output by an additional input module electrically coupled to the input module via a terminal base.

An industrial control I/O module for interfacing with industrial control equipment, such as sensors and actuators, can be configured to dynamically provide differing resistances in each channel as may be required for reliably achieving particular modes of operation in the channel. Providing differing resistances in such channels flexibly allows different modes in the channel to provide universal I/O capability. Modes of operation could include, for example, digital output, digital input, analog output, analog input and the like, in the same channel, but at different times. In one aspect, a processor or voltage divider can be used to control an amplifier, with feedback, driving a transistor in a channel to dynamically adjust resistance in the channel by selectively biasing the transistor to achieve a resistance in the channel suitable for the selected mode.

A method and input circuit unit having a first input circuit and a redundant second input circuit, wherein each input circuit includes an input for feeding a measurement current that can be obtained from a signaling device and that can be switched over and operated in such an input circuit unit, where the measurement current causes a voltage drop across a measurement resistor that can be evaluated as a measured value, where a parallel connection of the first and second input circuits causes division of the measurement current among the first and second input circuits, and where at least one input circuit include a device for compensating the decreased voltage drop across the measurement resistor resulting from the division of the measurement current.

An industrial control I/O module for interfacing with industrial control equipment, such as sensors and actuators, can be configured to dynamically provide differing resistances in each channel as may be required for reliably achieving particular modes of operation in the channel. Providing differing resistances in such channels flexibly allows different modes in the channel to provide universal I/O capability. Modes of operation could include, for example, digital output, digital input, analog output, analog input and the like, in the same channel, but at different times. In one aspect, a processor or voltage divider can be used to control an amplifier, with feedback, driving a transistor in a channel to dynamically adjust resistance in the channel by selectively biasing the transistor to achieve a resistance in the channel suitable for the selected mode.

An industrial control I/O module for interfacing with industrial control equipment, such as sensors and actuators, can be configured to dynamically provide differing resistances in each channel as may be required for reliably achieving particular modes of operation in the channel. Providing differing resistances in such channels flexibly allows different modes in the channel to provide universal I/O capability. Modes of operation could include, for example, digital output, digital input, analog output, analog input and the like, in the same channel, but at different times. In one aspect, a processor or voltage divider can be used to control an amplifier, with feedback, driving a transistor in a channel to dynamically adjust resistance in the channel by selectively biasing the transistor to achieve a resistance in the channel suitable for the selected mode.

A bus coupler for coupling field devices to a superordinate bus system includes an impedance converter arranged in a series circuit with a terminating resistor between a signal input and a field device output to enable a comprehensive diagnosis option separately for each transmission line and the connected field device, wherein the terminating resistor assumes the function of a line terminating resistor and a current limitation, and where a controllable reference voltage source enables the maximum output current to be defined and the output shut off.