This blog is dedicated to open, interoperable manufacturing software and the coolest, latest and greatest things I see every day while conducting business under the banner of Inductive Automation.

Hello, my name is Steve Hechtman and I am president of Inductive Automation. During the span of one day there is more excitement, more discovery than I can possibly keep to myself. This blog is, therefore, my outlet. WARNING: This site is highly biased in favor of the most powerful, affordable manufacturing software in the world - Ignition by Inductive Automation!

Modbus TCP - Lingua Franca

Lingua franca = a common language used by speakers of different languages.

Modbus TCP is just that for the controls industry. A look at interface options for a wide array of devices shows that everything from flowmeters to lighting controllers, VFDs to PLCs, generators to weigh scales and even things like solar cell controllers generally provide an option for Modbus TCP connectivity. On the PLC front, it is interesting to note that many newer PLC controllers support Modbus TCP no matter what their native protocol is.

For this reason, we decided that Modbus TCP would be one of the first drivers we should develop for our free OPC-UA server. But to achieve address space browsing, something I earlier dictated any driver we develop would have, is easier said than done. Obviously, dealing with such a wide variety of devices with widely divergent address spaces is a problem. So we solved that with templates. You map your address ranges and data types and then can browse anything in those ranges. Then that template can be saved and reused. For example, you can download a couple of templates for Automation Direct controllers from our website. More templates will be added over time, but in the meantime you can create your own. Creating them is simple and intuitive.

One thing we were amazed about is how fast Modbus TCP can be. During development of the driver we were working with one customer that had really fast requirements, so we just kept refining the driver until they were happy and the result was nothing short of amazing. I imagine this was possible because the Modbus TCP protocol is so simple.

I believe that we probably have the fastest, most user-friendly Modbus TCP driver on this planet. You, of course, can use it for free because we don't charge for it at all. Not for the OPC-UA server and not for the Modbus TCP driver that comes with it. Why would we do this? I don't know, maybe we're crazy, but I'm betting that once you use it you'll want to see what else we're up to.

1 comment:

Nathan Boeger said...

I like what I hear, but it sounds too good to be true. Too simple. PLC communication has to be complicated - it always has been (end sarcasm).

Can you do bitwise or array reads and writes?

Can you format the data with different types - strings, different number encodings, etc?

You're setting me up to be very impressed. I'll have to see it with my own eyes.