MicroSAM™- Hardware at the Sensor Node

Doug Sandy

In my previous post, I discussed how PICMG was working on several specifications to accelerate the deployment of Industrial IoT applications.  Our work focuses primarily on interoperability at the sensor domain, where lack of standardization has been an impediment to wide-scale adoption.   This post describes in more detail how one of the PICMG specifications – MicroSAM™ — fills part of this need.  I will show how it fits by way of example.

A smart factory IoT installation can be viewed as consisting of many different layers.  At the highest layer are back-end and support functions including sales, procurement and business analytics.  Next comes operations of the plant.  Below that are individual pieces of equipment, which may be grouped into one or more lines of operation. The last layer is comprised of thousands of individual sensor nodes that interface directly with the sensors (e.g. temperature sensor, pressure sensor) or effectors (e.g. servo motor, solenoid) deployed in the factory.  This is depicted in the following figure.

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.  As such, the processing performance and I/O connectivity are targeted toward the sensor interface.  MicroSAM may exist in parallel with other PICMG technologies, where MicroSAM devices provide sensor connectivity, and MicroTCA®, COM Express®, or CompactPCI® Serial provide higher layers of control.

MicroSAM extends and co-exists with the existing open-sourced microcontroller ecosystem by offering a standards-based solution that has been designed specifically for embedded use.  Some of its key advantages are:

  • Full industrial operating temperature range
  • Small size (32mm x 32mm)
  • Low power consumption
  • Power filtering and signal conditioning for embedded installations
  • Reliable industrial-grade communications
  • Direct connectivity to a variety of sensor types (analog voltage, analog current, digital)
  • Latching connectors for secure connectivity
  • PWM output for motion control applications
  • Hardware interlock and trigger signals for multi-node synchronization

Perhaps the most exciting part about the MicroSAM specification that I can share with you is that it is going through the membership review process and is expected to be fully released in August 2020.  In my next post I will discuss how hardware abstraction and data modeling can be combined with the MicroSAM module to provide plug-and-play at the sensor layer.  Until then, I would love to hear your feedback.  What sensors or effectors do you see as most important?  Which MicroSAM features will best meet your needs?