Abstract: In some aspects, the HVAC field device described herein includes: a housing; an HVAC functional device; a non-volatile memory unit including: a first set of computer-executable instructions in a first memory partition configured to execute an operating system; and a second set of computer-executable instructions in a second memory partition configured to execute an application module, wherein the application module is configured to control operation of the HVAC functional device; a volatile memory unit; and at least one processor configured to: execute the operating system in a first memory region of the volatile memory unit and execute the application module in a second memory region of the volatile memory unit, wherein the application module is prevented from accessing the first memory region of the volatile memory unit.

Abstract: A method of detecting an operating condition of a controllable flow regulator in a fluid flow channel of an HVAC system, comprising transmitting a sonic signal, from a sonic transmitter, directly or indirectly to the flow regulator, the sonic signal being distinguished from background noise by being at least one of: (i) modulated according to a modulation schema, (ii) an ultrasonic signal, (iii) a frequency selected to be away from background noise, receiving a signal from a sonic receiver for detecting the transmitted signal after interacting with the flow regulator; and determining, in an electronic signal processor, the operating condition of the flow regulator on the basis of the signal received.

Abstract: A method of detecting an operating condition of a controllable flow regulator in a fluid flow channel of an HVAC system, comprising transmitting a sonic signal, from a sonic transmitter, directly or indirectly to the flow regulator, the sonic signal being distinguished from background noise by being at least one of: (i) modulated according to a modulation schema, (ii) an ultrasonic signal, (iii) a frequency selected to be away from background noise, receiving a signal from a sonic receiver for detecting the transmitted signal after interacting with the flow regulator; and determining, in an electronic signal processor, the operating condition of the flow regulator on the basis of the signal received.