EMOD Module: Ethernet + Modbus

Considered the backbone of control system applications for more than 30 years, the serial communication protocol Modbus RTU became incredibly popular after it was introduced in the late 1970s for several reasons.

As an open protocol, there were no royalty fees to pay, plus the validation that it provided for performed tasks was a major advancement. In high availability industries like oil and gas that confirmation is critical to ensuring systems stay up and running.

Modbus was frequently deployed to connect a supervisory computer with a remote terminal unit in SCADA and control systems and was adopted across a wide range of industries, typically to transmit signals from instrumentation and control devices back to a main controller. 

Today, there are many legacy Modbus RTU systems still in place, and Modbus is also used in some new installations that involve simple on/off or open/close tasks. It’s easy to use and relatively inexpensive.

But all things change eventually, and many Modbus RTU users have begun looking at Ethernet for its advanced speed. This often leads to a scenario where an application is running on two separate networks – one Modbus and one Ethernet, which is costly and adds unnecessary levels of complication.

Phoenix Digital has designed a unique solution for this: its EMOD module, which support both serial Modbus and Ethernet on the same redundant fiber at the same time without programming or configuration.  With EMOD, Modbus and Ethernet no longer have to be isolated in their own network media environments. This gives more “life” to the Modbus system while offering substantial savings in componentry, wiring and wiring costs.

EMOD also provides a great deal of flexibility and allows for a phased migration from Modbus RTU to Ethernet. While most of the network continues to run on Modbus, the operator can add Ethernet units one at a time.

These plug-and-play fiber optic communication modules provide multi-fault tolerant, redundant Ethernet and serial Modbus communication for Rockwell Automation's I/O and Peer to Peer Networks. The modules are available as 1756 chassis plug-in modules, or as standalone, DIN-Rail modules for non- Rockwell applications.

If you’re interested in migrating from a legacy Modbus system to Ethernet, you can rely on Phoenix Digital’s long-time expertise. Contact us today to learn more.