System design perspective for PLC with/without IoT Gateway
For one of my client, I'm designing IoT device that can be deployed on machines in manufacturing. The goal is to monitors OEE, machine utilization, and downtime for maximum production efficiency and deep operational insights.
Now to solve this problem, I can think of two solutions
* Use PLC with IoT connectivity
- Use standard Gateway and connect to existing PLC (non-IoT)
In the first approach, we'll have to replace the existing PLC which will be difficult to convince client. As this solution becomes very expensive.
In the second approach, I'll have to design the IoT Device that can communicate with existing PLCs over protocols like OPC/UA, Modbus, S7, HTTP, TCP, etc.
To reduce the cost and provide flexibility. I'm thinking of designing IoT Device from scratch where Node-RED will be used to connect data from different types of hardware and sensors.
Would like to hear toughts, challenges, and suggestions on choosing the correct hardware, software framework, techologies, etc.
Thanking you!
2 Replies
I propose starting with the simplest solution that would provide the expected business outcome. Your case is very similar to the one I described a few days ago on my blog:
https://www.thingrex.com/legacy_factory/
The suggested approach is to install independent devices gathering required data without impacting operations (you do not want to start that engagement by replacing existing PLCs). I do not know if that is feasible in your specific case, but you might consider it.
Deployment of an Edge Gateway is a significant project. Gateways provide tons of interesting options but are an overkill in many scenarios. If you decide to go with that setup, I suggest using AWS IoT Greengrass:
https://docs.aws.amazon.com/greengrass/v2/developerguide/what-is-iot-greengrass.html
Hope that helps @Umesh Lokhande !
A legacy production line in a factory is not easily "abstractable".
A legacy production line in a factory is not easily "abstractable".
What is AWS IoT Greengrass? - AWS IoT Greengrass
AWS IoT Greengrass V2 is a service that provides AWS Cloud capabilities across all of your local devices.
I will suggest you place the suggestion to the client and let him decide. But designing the IoT Device will be much better. Which MCU or SoC do you intend using
Thank you so much for your detailed input. I agree with you to keep things simple. I decided to design a simple IoT device that can communicate with existing PLCs over TCP using an ethernet port. Between IoT device and server communication will be taken care of by MQTT. Once these devices are deployed on 10-15 machines, I'll concentrate on data to prove the business value. The goal is to log the machine parameters like up/down time, and log fault parameters during production. Meanwhile, I'll explore AWS Greengrass. Will keep you updated on the progres on this thread. Thank you!
Good luck with your project!
Hi, @Joseph Ogbonna, I am going with the RPi Zero module and designing a custom PCB adapter with Ethernet PHY on it. As Zero board doesn't have ethernet. I'm familiar with paho-mqtt client library (python). I believe this will help to keep things simple until business value is shown to the client. I'll keep you updated with progress and challenges with PCBs in the future. Thank you so much for your input. Have a beautiful day!
Great, keep me updated on the progress, any challenge on the pcb design you can always ask.
Hi, I hope designing hardware around ENC28J60 Stand-alone Ethernet Controller with SPI will not take much time. I have 2 months to complete this incl. s/w + h/w + field testing. Also, I've to figure out an HDMI standalone display to be deployed along with it. But now I only want to focus on the core logic. Once data satisfies the customer then comes the casing part where the display will be mounted. Thank you!