Smart Factories and the Challenges of the Proximity Network
2.3.1 POWERING THE EDGE DEVICE
Factories typically have ample power supplied throughout the facility, often making it easy to drop power to an edge node, but this does have its cost and difficulties. The choice of battery power or wired power to the edge device is a prime influencer of the connection technology decision.
For Process Improvement
In most cases, process automation applies wired power to the edge device in the factory. For example, a factory uses dedicated power to run the robotic arm that loads the products into shipping crates. But in some cases, the edge device is hard to reach with dedicated power. For example, one factory we toured has a large furnace that runs at 2000 degrees Fahrenheit, which makes running power wires to a sensor inside the furnace a difficult and costly task, particularly when the sensor was not built into the furnace by the manufacturer.
For Predictive Maintenance
As opposed to process improvement, predictive maintenance systems are backup systems. Plant managers often pay less to have these installed or will have them installed while they are implementing a process improvement initiative. Additionally, the sensors are often mounted onto existing equipment in ways that were not originally intended by the equipment vendor. Installers typically wire power to predictive maintenance edge devices only if it is cheap and easy to do so, otherwise they look to battery-operated edge devices.
A recurring example of predictive maintenance that we have observed in our tour of factories and plants is placing vibration sensors on motors in order to predict when an engine failure is going to occur.
2.3.2 NETWORKING THE EDGE DEVICE
Most factories have wired Ethernet drops throughout the facility. In some cases, it is not cost effective to wire networking to each edge device. The use case dictates whether the edge device should have wired or wireless connectivity.
For Process Improvement
When attempting process automation as a means of process improvement it will usually require wired networking to the edge device for data reliability and bandwidth. Fortunately, process monitoring does not typically require such high levels of precision, as those involved are looking for long-term trends, which means a few lost data-packets will not undermine the solution.
Process monitoring use cases often desire wireless connectivity in order to avoid the costs of running network cabling throughout the factory( One factory operator said it can cost up to $ 1,000 per foot to run cabling to an edge device). Also, some process monitoring needs to be done on objects than cannot be easily wired. For example, in a chicken processing plant, the
IIC Journal of Innovation- 67-