Introduction: What Are Embedded Controls & Systems?
In the world of industrial and factory automation, systems acquire data through inputs, process these inputs using some algorithmic functions such as Math and Logic, and output some data or commands to peripherals. Such systems are further capable of interfacing with other ‘systems’ via networks (serial, parallel, Ethernet etc.) utilizing shared protocols such as Modbus, Canbus, Fieldbus among others.
These systems are often referred to as Distributed Control Systems (DCS), Programmable Logic Controllers (PLC), Programmable Automation Controllers (PAC) or Supervisory Control and Data Acquisition systems (SCADA) among other names.
Further these systems utilize high level programming interfaces such as ladder-logic, function block diagrams (FBD) and Sequential Function Charts (SFC) among other common schemes. Many of them meet the standards published under IEC 61131-3.
So, how are Embedded Controls and Systems different from or similar to these systems? At a very basic level, a system comprises of inputs, a processor that performs math and logic functions and outputs that can drive final control elements. To that extent, an Embedded Control System is very similar to traditional control systems.
Where these systems differ are:
- An embedded system is generally built on a single board microcontroller or processor with a barebones operating system, real-time operating system or no operating system, depending on the application.
- An embedded system does not have any firmware or control package pre-installed. Everything is customized to the specific needs of the application.
- An embedded system is typically programmed using a high level programming language such as C, C++ or C# and does not include any support for more traditional frameworks such as ladder logic or FBDs.
- An embedded system can support any and all communications interfaces and protocols with custom code.
- An embedded system can typically provide better performance because of reduced overhead on the processor. Further, many embedded systems include an FPGA on-board which makes data signal processing easier and efficient.
- Generally, embedded systems are lower cost, particularly for small or unique applications where a larger commercial system would not be a good fit.
- Finally, embedded systems are ideal for applications such as machine controls and single unit operations.
- Embedded systems are also ideal for Industrial Internet of Things (IIOT) applications where small, efficient custom processor boards with minimal connectivity is required.
Embedded Controls And SIL4 Systems
SIL4 Systems brings decades of experience in Embedded Systems and Controls to help you design and implement the perfect solution for your specific data acquisition or control needs.
SIL4 Systems has commercial embedded systems built on industry standard form factors such as VME and PC104.
Custom form factors can be designed, as necessary.
Processor – FPGA
The main CPU typically includes a high speed processor and an on-board FPGA with the processing load shared between the two using custom firmware. For safety assured applications, multiple processor boards can be combined with cross-check redundancy to meet a desired SIL level. For SIL4 assurance, a diverse processor system would be applied.
Depending on the processor and the application, the system could have a minimal OS, a full OS, a real-time OS or no OS. Traditional OS’s like Windows and Linux are easily supported on most platforms.
Most processor boards have some on-board RAM with a solid-state drive for the OS/Application. Depending on the board design and application, an external solid state drive can be supported for full extensibility.
Most traditional types of inputs and outputs are natively supported. These include Discrete, Analog and Pulsed Inputs. Similarly, most types of outputs are also natively supported such as Discrete and Analog. Other output types such as PWM can be easily added.
Most boards support multiple communications interfaces such as serial, including RS-232/485, USB, Canbus and others. Ethernet connectivity is also included in the main board including support for Gigabit Ethernet. Power over Ethernet can be supported on a custom basis.
WiFi, 4G-LTE And GPS
Wireless Ethernet, 4G-LTE cellular and GPS interfaces can be added, as necessary.
Typical applications for embedded systems include, among others:
- Machine control
- Retrofit systems
- Custom SCADA systems
- Custom event/data recorders
- Remote I/O systems
- Custom interfaces to third-party systems
- OEM (proprietary) machines, processes and applications