PICMG CTO Doug Sandy presents PICMG industrial IoT initiatives. The video was first presented at Embedded Tech Trends 2021.

MicroSAM is the first PICMG specification in a series of IIoT-related open standards to reach ratification. It is the only open hardware specification to date that addresses the fast-growing sensor market. MicroSAM enables a fundamentally different IIoT architecture, offering a distributed architecture with true Plug and Play network integration. The specification defines a 32mm x 32mm module hardware platform for traditional sensor vendors wishing to quickly create smart sensors.

MicroSAM fills a need not currently addressed by other industry specifications; namely, a compact module targeted at microcontrollers for each of the Industrial IoT sensor nodes. The processing performance and I/O connectivity are targeted toward the sensor interface. MicroSAM may exist in parallel with other embedded technologies, where MicroSAM devices provide sensor connectivity, and PICMG standards such as COM Express®, CompactPCI® Serial or MicroTCA® provide higher layers of control.

Other specification work includes requirements for common firmware features, common data model, network architecture, and integration with the Distributed Management Task Force’s (DMTF) Redfish management API.

PICMG developed this specification to benefit the industry in three specific ways:

1. It will enable sensor vendors to create smart sensors without having to manufacture the control circuitry and/or software by purchasing these components from PICMG-compliant suppliers.
2. It will enable controller suppliers who wish to create smart sensors or smart-sensor components to do so in a way that is interoperable with other suppliers.
3. Accelerate the uptake of smart-sensor technology through open-specifications and interoperability.

MicroSAM was developed in collaboration with the following PICMG members: ADLINK Technology Inc., AMI USA Holdings Inc., Arroyo Technology, Avnet Integrated, Elma Electronic, ept, Intel, Lodz University of Technology, nVent, Samtec, TE Connectivity, Trenz Electronic, and Triple Ring Technologies.

A group of ancient philosophers and a mathematician (an engineer of the day) enter a room.  The philosophers are engaged in a familiar debate. “What is a chair?”  asks the first philosopher to the others.  “In its very essence, what properties describe chair-ish-ness?” asks the second.  The third chimes in: “Is a chair defined by its function and/or purpose, or something else?”  Shaking his head at the still-standing philosophers, the mathematician walks to the nearest bench and sits down, declaring “If this isn’t a chair, it’s good enough for me.”

While this short story may seem a bit foolish, lately I find myself in the unlikely shoes of the philosophers from the tale.  Within the PICMG IoT Network Architecture and Data Model technical subcommittee, we are asking the same questions, namely: “what is the general form of a sensor or effector (motor)?”, and “what properties are needed to encompass the variation that we see across sensors or effectors?”  Answering these two questions, along with generalizing the behavior of the device, constitute the work of “data modeling” and are at the heart of PICMG’s strategy for interoperability in IoT.  Let me explain how.

Suppose we are designing an IoT-enabled piece of factory equipment that has need for a motor.  The role of the motor is to move to a specific rotational position as fast as possible.  In this simple use case, it accepts one parameter (position) and performs one action (moves to the specified position), as shown in the following figure.

In creating this simple generalized motor model, we have also abstracted away hardware-specifics.  It does not matter whether the motor is a servo or a stepper – if the behavior coincides with our model, either might be acceptable.  Likewise, the vendor of the motor does not matter either. So long as the motor provides the same behavior as dictated by the model, interoperability is achieved.

Of course, real motor use cases are somewhat more complex than the one we outlined above. Motors can be used to do more than just move to a specific position.  They can be used to rotate at a constant speed, follow complex motion profiles, and even synchronize their motion with other events.  Precision, error, and torque characteristics may also be important.  This points to the need for a more complex behavioral model and more operating parameters, but results will be the same – a generic data model, hardware abstraction, and multi-vendor interoperability.

The PICMG IoT Network Architecture and Data Model technical subcommittee is currently working on data models for generalized sensors and motion control. 

If you would like more information on this work or would like to join in the effort, please contact me.  Feel free to send me your reactions – I would love to hear from you.