An IoT interface for industrial analog sensor with IEEE 21451 protocol

An Internet of Things (IOT) interface is introduced in this paper with the goal of filling the compatibility gap between currently available industrial analog sensors (legacy sensors) and network protocols. It is intended to be compatible with conventional analog sensor outputs with current loop, voltage and pulse outputs. Connection to the Internet is via Ethernet. To this end, IEEE 21451 family of standards is employed as a reference to come up with an interoperable interface. This family of standards provide an infrastructure which allows auto configuration (plug and play) and interoperability without the need for operator intervention. Transducer electronic data sheets (TEDS) play a key role in this process and they supply the system with the operating characteristics that are needed to use the transducer modules. The TEDS-only version of this family of standards (IEEE 21451-4) has received significant attention and is being used in this paper. The developed interface consists of transducer interface module (TIM) and network capable application processor (NCAP). Any type of industrial analog sensor can be connected to this interface and the interface will convert the input signal from analog to digital, format it in engineering units and then ref-format it in Internet format. The primary format of IEEE 21451-4 is XMPP which emphasizes on interoperability and security of messages in a network with machine to machine (M2M) communications that can be sensors, actuators and other type of devices.