Method and apparatus to identify connected device types on an I/O channel based on current characteristics

A system for identifying a type of a device connected to (Input/Output) I/O channels of an I/O module in an industrial process control and automation system, the system comprising:

• at least one processor;
• and
• a non-transitory computer-usable medium embodying computer program code, wherein the computer-usable medium communicates with the at least one processor, the computer program code comprising instructions executable by the at least one processor and configured for:
• electrically applying a current for a predefined time duration to at least one I/O channel among the I/O channels of the I/O module of the industrial process control and automation system, wherein each I/O channel among the I/O channels is characterized by different inputs, outputs, voltages, currents, and configurations corresponding to the at least one I/O channel;
• electrically initiating a current readback from the at least one I/O channel at a regular interval of time within the predefined time duration;
• electrically operating the current readback based on a loop current maintained between the at least one I/O channel and the device connected to the at least one I/O channel;
• electrically determining values of the current readback for each of a time interval during the predefined time duration;
• storing the values of the current readback in a memory associated with the I/O module;
• electrically determining a pattern as a function of the values of the current readback and a sample of the time interval for the device connected to the at least one I/O channel, the device comprising at least one of:
• a sensor and an actuator of the industrial process control and automation system;
• electrically identifying the type of the device connected to the at least one I/O channel based on the determined pattern of a current sink of the device connected to the at least one I/O channel in the industrial process control and automation system, wherein the determined pattern comprises a waveform of the current sink including a current drop and a current release of the device connected to the at least one I/O channel, wherein the identified type of the device comprises a smart device when a range of the current readback associated with the device falls in at least one range during a test sequence within the predefined time duration, the test sequence including:
• a first test for a first range between 23 mA to 35 mA in the at least one range,
• a second test for a second range between 23 mA to 25 mA in the at least one range, and
• a third test for a third range between 1 mA to 2 mA in the at least one range;
• adding the determined pattern of the identified type of the device in a device bit pattern stored in a persistent storage, wherein the device bit pattern, included in the persistent storage, comprises a plurality of patterns of the current sink of the device connected to the at least one I/O channel in the industrial process control and automation system, for future use to identify the type of the device during run time;
• and
• electrically switching off the current applied to the at least one I/O channel associated with the I/O module of the industrial process control and automation system after the addition of the determined pattern of the identified type of the device in the device bit pattern.

An apparatus, comprising:

• an I/O (Input/Output) module having at least one processing device, at least one I/O channel, and a memory associated with the I/O module of an industrial process control and automation system, wherein the at least one processing device is configured to:
• electrically apply a current for a predefined time duration to the at least one I/O channel among the I/O channels associated with the I/O module of the industrial process control and automation system, wherein each I/O channel among the I/O channels is characterized by different inputs, outputs, voltages, currents, and configurations corresponding to the at least one I/O channel;
• electrically initiate a current readback from the at least one I/O channel at a regular interval of time within the predefined time duration;
• electrically operate the current readback based on a loop current maintained between the at least one I/O channel and a device connected to the at least one I/O channel;
• electrically determine values of the current readback for each of a time interval during the predefined time duration;
• store the values of the current readback in the memory associated with the I/O module;
• electrically determine a pattern as a function of the values of the current readback and a sample of the time interval for the device connected to the at least one I/O channel, the device comprising at least one of:
• a sensor and an actuator of the industrial process control and automation system;
• electrically identify a type of the device connected to the at least one I/O channel based on the determined pattern of a current sink of the device connected to the at least one I/O channel in the industrial process control and automation system, wherein the determined pattern comprises a waveform of the current sink including a current drop and a current release of the device connected to the at least one I/O channel, wherein the identified type of the device comprises a smart device when a range of the current readback associated with the device falls in at least one range during a test sequence within the predefined time duration, the test sequence including:
• a first test for a first range between 23 mA to 35 mA in the at least one range,
• a second test for a second range between 23 mA to 25 mA in the at least one range, and
• a third test for a third range between 1 mA to 2 mA in the at least one range;
• add the determined pattern of the identified type of the device in a device bit pattern stored in a persistent storage, wherein the device bit pattern, included in the persistent storage, comprises a plurality of patterns of the current sink of the device connected to the at least one I/O channel in the industrial process control and automation system, for future use to identify the type of the device during run time;
• and
• electrically switch off the current applied to the at least one I/O channel associated with the I/O module of the industrial process control and automation system after the addition of the determined pattern of the identified type of the device in the device bit pattern.