Communicating with Omron PLCs

Omron PLCs support a variety of communications methods and protocols including standards such as DeviceNet and Profibus. They also support some native protocols, including:

• Sysmac Way (also called HostLink) - a simple serial protocol supported by every Omron PLC.

• FINS (Factory Intelligent Network Service) - a network protocol using UDP/IP that supports networked PLCs.

Plant SCADA provides the following drivers to support these communication methods:

• OMRON Driver - which implements the Sysmac Way serial protocol

• OMFINS Driver - which natively implements the FINS protocol

• FINS Driver - which uses FINS Gateway middle ware to communicate using the FINS protocol.

To support communication with the FINS gateway middleware, Plant SCADA also includes a low level FINS transport driver.

Complicating the issue further is the fact the range of Omron PLCs is logically split into three distinct series:

The differences between each series is most noted when using Serial communication. Plant SCADA's OMRON driver is designed for serial communication with only Series 1 devices. It is based on Omron's native C-Mode HostLink protocol, which is too simplified to support all the tag types required by the Series 2 and 3 devices. Therefore, serial communication with these devices is based on the FINS encapsulation protocol, which requires Plant SCADA's OMFINS driver.

Each series also requires Plant SCADA to provide a separate variant of the FINS and OMFINS drivers. Each variant is indicated within a project configuration by a numeric suffix on the driver name, i.e. OMFINS1, OMFINS2, OMFINS3.

The following table should help you decide which Plant SCADA driver you will need to use to communicate with a specific Omron device.