I look at the world a little oddly, to say the least. It seems that I’m out of step on a lot of things. Name all the great social issues of the day and ask where most Americans stand and I’m on the other side of the tracks. Sometimes, on the other side of the tracks and lost in the tall weeds with my feet stuck in mud up to my ankles.
I’m that way on a lot of technical issues too but don’t think I’m too far afield on this one. I divide up the scanner world into three groups. The first are PLCs from the big PLC vendors like AB, Siemens and the rest. These are generic controls designed to handle just about anything. They’ll happily sell you one to control a Molson Beer process, an Injection Molding machine or a Viagra dispensing machine.
The second group is controllers for more dedicated applications. They’ll usually control a small set of devices with a pretty specific focus. The user usually has the ability to add and remove a node. Smaller, more dedicated, less adaptability over all a more focused operation. A robot is a good example of this kind of controller. The amount of I/O available to the robot varies within some bounds.
The third group is the real embedded controllers. These guys are buried within a process or a machine. They have very specific functionality defined by the system vendor. They are going to scan x devices no matter what. The control program is going to be hard coded and not altered by a user.
If these systems use EtherNet/IP the way the scan list gets defined varies for each of these applications. In the third, it doesn’t vary at all. It’s hard coded and set by the manufacturer. The scanner has a list of EtherNet/IP TCP/IP addresses and I/O buffer sizes. It’s gonna scan that list until the cows come home.
In the first and second group, we have much more variability. There’s actually three ways to configure that scan list:
- Hard code it – just like the third group of controls. Unfortunately since the applications will vary, hard coding is just not an option.
- Vendor Specific configuration – most vendors have their very own tool for configuring their device. It’s some sort of PC program and a lot of them just want to extend that tool to do the EtherNet/IP scanning. That’s OK but a lot of end users really don’t like that for good reason. Where is that tool going to be when they need it? How do they know they have the most recent one? How do I use it again?
- Open Configuration Interface – This is really the best way to enter your scanlist. Using the EtherNet/IP Connection Configuration interface any off-the-shelf tool that supports that interface can configure a scan list for your EtherNet/IP scanner.
RTA just announced support for the Connection Configuration Object in all our EtherNet/IP Scanners. This interface uses standard EtherNet/IP Explicit messages to add and remove nodes from the scan list, start and stop scanning and revise the data sizes of the I/O buffers that are exchanged by the scanner and it’s servers.
This is a real benefit to the user. They don’t have to maintain some separate tool. They can easily add and remove nodes from the scan list using the same command set that they use to configure nodes on the network so no extra training or management costs.
This is a huge step forward for RTA EtherNet/IP technology that will benefit all our customers using our small footprint, fast, reliable EtherNet/IP scanners.