The use of hard wiring is down according to Control Design’s recent survey of their readers, primarily machine builders it seems. Video: Market Intelligence Report: Sensors & Vision Part 1.
From 2008 to 2010 the respondents saying they used hard wiring went from 78% to 57%. This is certainly a step in the right direction, but why on earth are machine builders still hard wring at all?! Ok, if the machine is compact and the controller is on the machine it makes sense. That can’t represent that whole 57% though. If you listen to the analysis in the video, the point is made that the cost of wiring the sensor probably exceeds the cost of the sensor many times over. It just makes sense to use a network: AS-interface for simple devices or PROFINET-based IO modules for clusters of sensor and actuators. IO-Link should be used to connect intelligent sensors and actuators to that IO module in order to take advantage of remote access to the configuration and diagnostic data.
The use of wireless was also down. Surprising since it’s cheaper to run no cable than even a network cable. I think part of the problem may be the lack of a solid standard. We will remedy that early next year when our Wireless Sensor and Actuator standard is released (it’s in the review phase now). It uses IO-Link as the protocol and is designed to coexist with other wireless applications like WiFi and WirelessHART.
If machine builders need to gather some knowledge about networks, we are offering our free one-day training classes on PROFIBUS and PROFINET again in 2011. And we have webinars archived for those who can’t make it in person.