PLCs are the most common intelligent system in the automation market. Most of them are not connected for 2 reasons: they are old or due to security concerns.
An automation solution provider needed to manage his PLCs in the market from the Web to provide a new level of service to the customer (24/7) with an annual fee.
DEVICES AND CONNECTIVITY
PLCs are super reliable and are a standard in the automation market. Most of them installed during the ’90s are still up and running.
The modern ones are providing connectivity like LAN in general, but customers prefer to keep separated (via hardware) the PLC from the Internet.
In this case Iomote X400 Gateway is been the best choise since it’s able to talk with the PLC via serial port (RS485) and has been programmed to be able only to read data (not to write) in order to guarantee max security.
The RS485 communication protocol is not a standard one (like Modbus for example) but the PLC offers a custom one with a simple request-response structure.
The customer was able to program this protocol on the X400 Gateway using the Arduino IDE in less than 8 hours, leveraging also on the libraries available across the Arduino community.
Packed data, in Json with a timestamp, are sent to the Cloud via a 3G connectivity since the customer preferred to avoid any connection to the company network.
CLOUD & APPLICATION
Data coming from PLCs retrofitted with X400 fleet are stored into a database (telemetry), but in the case of Alarms they are triggering an email notification.
In this way the operator is always ready to control his fleet of PLC, to answer the customer requests of support or even to setup actions to anticipate possible failures.