Let’s face it; an installed base, a trained maintenance crew, and an established set of procedures all make it really difficult to try to implement any new technologies in a running manufacturing facility. The idea of an industrial network providing detailed data about your processes and improving productivity sounds interesting and valuable, but where do you begin? Retrofitting everything with the newest technology isn’t an option in today’s economy, the capital investment is just too great. But there is hope! And with small steps, time and training, any plant can move forward into the ethernet realm and beyond.
“I already have an existing network (PROFIBUS, PROFINET, EtherNet/IP, CC-Link, etc…) so why would I be interested in an IO-Link enhancement?”
The answer is simple, instant SCALABILITY!
What do I gain by having an additional 4 IO-Link channels?
In my recent travels of the east coast from Boston to Tampa, customers have been looking for quality solutions to be able to run:
and multiple sizes,
and multiple form-factors,
all on one production line.
Two things about this seem to be in every application:
- Change-over needs to be simple for the operators.
- Management needs to see the cost/time savings, be it planned or unplanned downtime.
But how can I do multiple recipes or multiple jobs on one machine? I have to reprogram/reposition sensors, move guide rails, swap out components, etc…
Typical IP67 network topologies involve stand-alone I/O modules, providing 8 to 16 points of I/O per module. In some applications multiple stand-alone modules could be mounted within inches of each other. Thus was introduced the IP67 Network I/O Island, a modular IP67 I/O solution that allowed 8 to 60 plus I/O points to be connected to only one network node. This solution provided initial costs savings by reducing the number of network nodes used in an application, but brought along some new problems. One problem involved exceeding long sensor /actuator cordsets, with a centralized I/O solution remote sensors needed cordsets of 5, 10, or even 15 plus meters in length. The second issue was cordset management; imagine tracing a suspect cordset to the network I/O island with 60 plus connectors hanging off of the front of the unit.
Regularly I attended free one day seminars on Profibus & Profinet put on by the PI Organization. They have two different classes that they offer in cities all over the US and Canada. There are usually about 50-100 attendees and it is a great opportunity to network with local engineers from and around the area in a wide variety of industries.
In the seminars they cover these topics in general:
- The history and breadth of the PI Organization
- Different ways to build I/O architectures and how to integrate them
- Why networks are important and how to select a network
And they cover in detail (using vendor products and Siemens PLCs):
- How to design a network
- Configuration of a network using the PLC
- Installation considerations, cabling & hardware
- Commissioning a system
- Long term maintenance and troubleshooting
- Plantwide Energy Conservation
During breaks, multiple vendors of Profibus & ProfiNet related products were available to discuss applications and projects with the attendees and provide valuable resources for industrial network design.
If you are unfamiliar with Profibus, ProfiNet or IO-Link I recommend you attend one of these seminars to learn about how it can help your machine design.
I updated the text in this entry on 3/8/2011.
Paradigm shifts in automation are always occurring. The need for cost savings and higher diagnostics caused the shift from IP20 I/O to IP67 I/O. Now, we are in the midst of a shift to reduce or eliminate enclosures in industrial applications by removing control and power from the cabinet. With the reduction of IP20 I/O and enclosures, adding more I/O (discrete and analog) or specialty devices (RF identification, measurement devices, etc…) is now more difficult. In the past it was relatively easy, but expensive, to add another “slice” of I/O to an existing IP20 solution.
In most industrial applications 80-90% of the I/O going back to the PLC is discrete points. Multiple times I have been asked, “How can I easily, quickly, and cost effectively get one channel of analog back to my PLC”. The solutions in the past have either involved an IP20 slice I/O solution in a J-box, which is expensive and labor intensive, or an IP67 network module, which reduces labor costs but still carries a high cost. A common drawback to these solutions is that you have to pay for 2, 4, or even 8 channels when only one is required.
Industrial networks are nothing new; ASi, CANbus, DeviceNet, Profibus (to name a few) have all been around for years. Designers of production equipment use networks for a variety of reasons: simplified machine mount I/O, motor starters, valve bank control, etc. Each network has a limited number of devices that can be connected and each device is designated a node address or IP address. IO-Link takes a standard network and expands it beyond its current capacity through flexibility and expansion.