2 PLC controllers leap to edge IoT Devices

Can a normal PLC be an edge controller? If the MQTT protocol and P/S system is in your future, then probably not. MQTT as a protocol is very lean and designed for small pieces of data transfer using small transfer pipes. It is a very compact protocol and is used by various devices, such as wireless temperature sensors.

    – Jeremy Pollard CET

groov Edge Programmable Industrial Controller (EPIC) from Opto22  is Class I, Div. 2-compliant, which is important in many industries. It has the full array of I/O modules with common wiring arms for all. The big difference here is the built-in LCD touchscreen running Ignition Edge from Inductive Automation or groov View. A full-fledged HMI/SCADA application built-in is very cool. Since it is an open platform, any Java-based application can run in the system. With Ignition Edge, you have access to multiple drivers, so you can have access to network-based data on the same screen.

EPIC can use the open standard MQTT publish/subscribe (P/S) model of data handling, in addition to the producer/consumer response model. The cloud uses P/S, so the system can and does integrate with the cloud seamlessly.

Bedrock Automation’s OSA Remote PLC/remote terminal unit (RTU)/edge controller. This controller boasts some of the same hardware specifications as its big brother, including a metal enclosure for high-energy pulse protection (EMP immunity). The I/O is universal and can be configured for analog, digital and/or protocols such as HART, Ethernet IP or Modbus TCP.

Bedrock believes that having a lower-cost, intrinsically secure device at the edge with smaller I/O counts will aid in the deployment of edge devices instead of standard PLCs and RTU devices.

Its SCADA connectivity is done with embedded OPC-UA. MQTT P/S and data distribution service (DDS) for cloud-based services will be forthcoming later in 2018.

What is cool about the device is its size. At 45 square inches and 2.3 inches deep, it can fit just about anywhere. The temperature range of -40 to +80 °C allows it to be used in some extreme environments. It will use Bedrock’s standard IEC 61131 software platform for configuration, which is free to all.