Gateways for Fieldbus and Industrial Ethernet

Typical connectivity scenarios with the X-gateways

Master/Slave considerations
Need assistance in choosing your right combination? The right X-gateway combination for your installation depends on whether your have 1 or 2 PLCs in your installation.

Example 1: Master/Slave combination when only ONE Master/Scanner PLC/Controller is used in the installation.
In this example using a Siemens PLC running Profibus the Anybus X-gateway is used to integrate a group of DeviceNet connected automations devices into the central control of the Siemens PLC. The X-gateway functions as a slave on the Profibus network and a scanner on the DeviceNet network.

Example 2: Slave/Slave combination when TWO Master/Scanner PLC/Controllers are used in the installation.
In this example a newly installed part of the plant based on an Allen Bradley PLC running EtherNet/IP as the top level network, shall be inter-connected with an existing part of the plant based on a Modicon PLC running Modbus. In this application the X-gateway is used to transfer selected I/O data and parameters between the two parts of the plant for synchronization and control. Both network interfaces of the X-gateway have slave functionality. The two PLC's are controlling the flow of data through the gateway by writing/reading data into/from the gateway.

Example 1 - Master / Slave

Example 2 - Slave / Slave

Connecting two networks of the same type. eg. ( Profibus >< Profibus )
In this scenario the X-gateway is used to inter-connect two installations both using the same type of network. This can either be a fieldbus network or an industrial Ethernet network.

Using the X-gateway in this scenario allows to inter-connect the two installations even in those cases when they are using different transmission speeds. Another benefit of this type of application is that the two installations can be logically and physically de-coupled from each other without losing the capability to transfer selected data between the two installations. Finally X-gateways can also be used as a logical extension when the maximum allowed number of devices to be connected exceeds the limitations of the network.

Connecting two different networks. eg. ( Modbus-TCP >< DeviceNet )
In this scenario the X-gateway is used to inter-connect two installations based on different networks. A very typical scenario is to inter-connect traditional fieldbus installations with modern industrial Ethernet networks. Another common application is connecting two different PLC installations via their different fieldbus/Ethernet networks. X-gateways can bring together the PLC worlds of Siemens, Rockwell, Schneider Electric, Mitsubishi, Beckhoff and Pheonix Contact etc.

Mapping of I/O and parameter data inside the X-gateway

The Anybus X-gateways provide a transparent pass for the data between the two networks. They do not change the sequence of the data nor do they change the data itself.

Input data on network 1 will appear as output data on network 2. Output data on network 1 will appear as Input data on network 2. The total amount of data transferred is limited to a max. 512 bytes Input and 512 bytes Output data. The transfer time between the two networks is typically 10-15ms. The X-gateway is handling the data consistently.

Cyclic I/O data, acyclic parameters
The X-gateways primary focus is with the transfer of cyclic I/O data between two networks. In additions and depending on network combinations, also acyclic parameter data can be transferred. ( eg. SDO, DPV1, PCP, or Explicit messaging ) The use of parameter data enriches the functionality of the gateway and allows for the transfer of time uncritical blocks of data between the two networks. The X-gateway can also mix parameter and I/O data to allow a very flexible inter-connection between the two networks.

Bits, bytes, words and objects
The X-gateways permits inter-connection of networks using different basic data types. An example of this are byte oriented networks such as Profibus with word oriented networks such as Modbus or even bit oriented networks such as AS-Interface. The mapping is basically a one to one mapping function between the two network sides. In addition it is possible to split-up a certain number of data out of a larger data portion and to transfer this selectively as parameter data on the other network.

Basic Slave <> Slave configuration The image below illustrates how data is mapped in a slave-to-slave combination.

Basic Master <> Slave configuration The image below illustrates how data is mapped in a master-to-slave combination. Advanced Master<>Slave configuration For diagnostic purposes the X-gateways provides optionally control and status information that informs the user about the network and gateway status. This information can be enabled as an option but will consume 2 bytes of Input and Output data per network.

Configuration

Easy configuration - No programming required!
No programming skills are needed to set up the X-gateway as defined in the above steps. As factory default the X-gateways have a pre-defined I/O size of 20 bytes I/O.

The configuration of the X-gateway is made via the in-built configuration interface. For this purpose a PC with a installed terminal program (eg. Windows™ Hyper Terminal) is connected via a serial RS-232 cable to the config port of the X-gateway. The easy to use config interface allows to define the I/O data sizes on each network side and to define the mapping and data splitting between cyclic I/O data and parameter data.

Configuring a Slave/Slave combination
In this scenario the configuration of the X-gateway is solely made via the in-built config interface without need for any additional configuration tools. However the X-gateway must be integrated into the master configuration of the corresponding PLC. For this purpose HMS provides the necessary electronic data sheets ( .GSD, .EDS, .CSP files ).

Configuring a Master/Slave combination
The configuration of the X-gateway is made in two steps. Firstly the amount of I/O and parameter data as well as the mapping of the data between the two networks is defined by using the in-built configuration interface. Secondly, the networkmMaster interface needs to be configured by using the appropriate master configuration tool such as Anybus NetTool or RSNetworx™ for CIP based networks.

Configuring the Ethernet network side of the X-gateway
If you have chosen an X-gateway with at least one Ethernet based interface ( Modbus-TCP, EtherNet/IP or Profinet-IO ), this Ethernet based network interface needs to be configured regarding its IP address settings. For this purpose the X-gateways has an inbuilt webpage that allows easy definition of the Ethernet address and parameter settings.

In case that you do not know your current IP address settings, HMS provides the free software "Anybus-IP Config Tool" which can be downloaded from the support section of this website.

IT Functions

X-gateway supporting the industrial Ethernet protocols Modbus-TCP, EtherNet/IP, Profinet, are supporting industrial IT functions in addition to the real-time data transfer. These IT functions provide a dynamic Web server, with SSI functions, client side Java scripts and applets, and FTP & File access permissions. IT functions can be used to design and display fully customized web pages for diagnostic, control or maintenance purposes. The IT functions also allow the definition of alarm values that are used to send an email to a pre-defined recipient in-case of the alarm value is reached.

X-gateway webserver provides useful status & diagnostic information.

Anybus OPC Server

With the "OPC Connectivity Feature" of the Anybus X-gateways, PC based OPC-Client applications can access fieldbus data via standard Ethernet networks.

The Anybus OPC Server enables any PC-based OPC DA client application to access data of distributed field devices located in a fieldbus network without the need for a PCI fieldbus interface card. The connection between the PC in the control room and the field devices in the plant is established via existing Ethernet networks and the Anybus X-gateway. In this concept, the X-gateway functions similar to a fieldbus PCI interface card. While the PCI card is located inside the PC in the control room, the X-gateway can be located directly on site and the expensive fieldbus cabling between the production line in the plant and the control room is eliminated. This saves installation cost and improves the flexibility.

The new “OPC Connectivity” feature is available for most Ethernet versions of the X-gateway family. Typical applications include OPC-based SCADA systems with remote visualization and control. The Anybus OPC server supports OPC Data Access (DA) v1.0, 2.05, 3.0. Key features include access to process data, an OPC tag editor and an online viewer/editor with read / write access to tag data.The Anybus OPC server is tailor-made for use with the Anybus X-gateways and PCI cards. It is available free of charge for download from this website.

KEY FEATURES

Support for OPC Data Access v1.0, 2.05, 3.0 enables access to Cyclic Process Data

Support for Windows 2000, XP, Vista

Additional parameter data supported ( Depending on network combination )

Up to 1536 bytes of data in each direction ( Depending on network combination )

OPC Tag Editor Included

Online diagnostics

On-line viewer/editior for monitor/modify of process tag data

For OPC download information: Anybus OPC Server