Getting connected!

Category: Articles Post Date: 27 August, 2014

Getting connected!

We live in an era of connectivity. There is a need to know what is happening, where and to know it now. This is no different in the industrial area, where information or the lack thereof can be measured, and it is often a large figure.

Knowing what the equipment is doing, the production rates, down times, fault locations, are all examples of things we need to know to improve the efficiency. At the start of my career in manufacturing, I was given an important piece of advice: “You can’t control what you don’t measure”. It was a simple statement, but one that stuck with me and as time moved on, I learned just how true that statement was.

It is one thing to know it, and it is another thing to do it. The next lesson was to learn to fear this other piece of advice: “You just need to connect product A to product B”. I’m not sure there is a statement that brings more fear into the heart of an integrator than that one. It seems that there are countless platforms, networks and protocols in the industrial area that will solve this issues. Even when the interfaces have the same name, it doesn’t guarantee it will be simple.

There are Bus Gateways or Protocol converters which allow two systems to talk to each other and exchange information. These devices however are typically expensive, and while effective in large systems, they can be prohibitive in a small system or application, where only 1 or two devices need to be connected.

Renu Electronics solves this dilemma with a low-cost, yet highly flexible range of gateways. These units allow a cost-effective connection even when only one device needs to be connected. Typical applications include linking 2 PLCs that are running different networks, connecting a PLC to Variable Speed Drives (VSD’s), and linking SCADA systems to various field devices or sub-networks. The flexibility of having specific drivers for certain PLC’s and drives, along with configurable data sets, means the gateway can reduce the work required to program the PLC/SCADA system.

For example, you have a PLC that needs to connect to a VSD and a couple of tank level sensors. Your PLC has a MODBUS interface so implementing a simple RS485 network will keep the wiring to a low-cost and be easy to install. The bad news is the VSD doesn’t have MODBUS, but it does have a serial connection. The level sensors have a HART interface and you have a potential aneurism wanting to burst. What’s more, the customer would love to have a web interface to be able to log in and see what is happening in his tanks any time. Now before you give up in defeat, this can all be achieved by implementing the Renu gateways. A GWY-00 Serial converter takes care of the exchange between the MODBUS and the Serial Drive, a GWY-800 provides a MODBUS to HART network connection, and the GWY-610 provides a MODBUS to Ethernet interface and has a built-in web server to allow the customer to have a webpage to keep an eye on everything.

The gateways are all configured with the free software, ensuring the various data fields you want are selected and are placed into a simple continuous structure on the MODBUS side. This allows the PLC to only deal with the data it needs to. It has everything in a simple group rather than trying to find information amongst a large buffer of data. It also ensures the network is efficient by exchanging only the data that is needed, rather than the entire data set for each device. The gateway can also run different data sets on different exchange rates. This way critical data can be updated every cycle, but diagnostic data, for example, can be sent every 5 cycles. You can choose which data and when. Some interfaces even support data on request (asynchronous).

Another bit of free software allows you to configure the webpage(s) in the GWY-610 and ensure the customer can see what is happening at any time and he can view it on his favorite browser.

Want to learn more about these Renu Electronics gateways? Get in touch with CellTec to find the best ways to connect to your world.



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