What is the main role of a PLC (Programmable Logic Controller) in industrial SCADA and IIoT environments?
PLCs are ruggedized digital computers designed for industrial automation to monitor inputs, run logic programs, and control output actuators.
Which IETF protocol provides secure transport layer security over UDP for CoAP communications in IoT?
DTLS (Datagram Transport Layer Security) provides security equivalent to TLS specifically tailored for UDP datagram protocols like CoAP.
In IEEE 802.15.4 frame structure, what is the purpose of the Frame Check Sequence (FCS) field?
The 2-byte Frame Check Sequence (FCS) at the end of an 802.15.4 MAC frame uses 16-bit Cyclic Redundancy Check (CRC) to detect transmission errors.
What standard data format is commonly used in MQTT payloads and RESTful CoAP APIs for light-weight data exchange?
Both JSON and CBOR (binary version of JSON optimized for CoAP) are standard payloads in IoT message communications. Thus 'More than one of the above' is correct.
Which device discovery protocol is built into BACNet networks to allow devices to automatically advertise their presence and capabilities?
BACNet uses 'Who-Is' unconfirmed request broadcasts to discover devices, which respond with 'I-Am' messages containing device IDs.