GESTIÓN DE ARCHIVOS
8. Preservación digital
The configuration data must be downloaded to all devices that are involved in IRT communication.
Before downloading, first perform a consistency check and eliminate any errors that may exist.
Recommendation
Sync domains are not limited to one station. Download the IRT configuration from the network configuration (NetPro).
To do this, select the Ethernet subnet and then select the PLC > Download to
Configuring IRT Communication
5.9 Media Redundancy
5.9.1
What You Should Know a About Media Redundancy
Media redundant transmission means that the data in IRT communication are transmitted in two frames over two separate paths. A frame is the unit in which data are transmitted over the Ethernet.
The "media-redundant transmission" property can the configured as follows: • For an entire IO device
• For each individual address area in a controller-controller communication relationship (direct data exchange)
Media Redundancy for an Entire IO Device
All data in the communication relationship between the IO controller and the IO device are transmitted in a media-redundant manner.
Media Redundancy for an Individual Address Area in a Controller-Controller Communication Relationship (Direct Data Exchange)
Media-redundant transmission is configured for each address area between sender and receiver. This means that, in each case, this corresponds to one row in the "Sender/Receiver" tab in the property sheet for an IO controller interface.
Configuring IRT Communication
Default Setting
When the communication relationship is created, media-redundant transmission is disabled. This means that the data in an IRT communication relationship are transmitted over precisely one path of the IRT network. If media redundancy is not enabled, this means that the data are transmitted over exactly one path between the IO controller and the IO device of the IRT network. If this path is interrupted, then the data transfer will come to a halt.
Topology for Media-Redundant Transmission
To increase the reliability of data transmission, media-redundant transmission may be used. When doing so, the topology must be configured so that there are at least two different paths available between the sender switch and the receiver switch. These paths are different when the switches for one path are not used by the other one.
A ring topology would fulfill this need 100%. The device to be used as a switch should be one that supports the planned IRT communication.
In addition, several rings can be combined with each other as long as the condition is met that a switch is used in only precisely one path. If the topology of the
network will not allow this, then the paths must be as "resource-independent" as possible. In case, however, media redundancy is not fully ensured.
The consistency check in HW Config will indicate whether switches between the sender and the receiver are being used by more than one path.
In addition to being configured for media redundant transmission, the network also requires a redundancy manager.
Function of the Redundancy Manager
The redundancy manager is an IO device that supports the planned IRT
communication and for which IRT topology must also be configured. This manager is necessary in order to open the ring structures, which are necessary for media- redundant transmission, for TCP/IP frames. Otherwise, the TCP/IP frames would continually circulate in the network. As far as IRT is concerned, the redundancy manager is "porous" since IRT communication is running as planned and there are thus no frames circulating in the network.
Configuring IRT Communication
The redundancy manager functions as an intelligent switch: • It sends test frames to both ring connection points.
• If the ring is still closed and functioning correctly, these frames are received again at the respective other sides.
If no test frames arrive within a time interval, the manager lets TCP/IP frames through again. In this way, a communications path for TCP/IP frames, which had been previously interrupted for the reason cited above, is created again. If the ring opens, the redundancy manager generates a redundancy interrupt.
Note
Enabling media-redundant transmission will increase the communications load since the data now have to be transmitted twice over two pathways.
Configuring IRT Communication
5.9.2
Configuring Media Redundancy
Configuring Media Redundancy for an Entire IO Device
All data in the communications relationship between the IO controller and the IO device are transmitted in a media-redundant manner.
Requirements
• A topology with two independent paths has been configured. • The IO device supports the function.
• A redundancy manager has also been configured.
Procedure
1. In HW Config, select the relevant IO device.
2. In the detail view of the IO device, double-click "Interface Submodule" for the IO device to open the property sheet.
3. Select the "Media Redundancy" tab.
Configuring Media Redundancy for an Individual Address Area in a Controller- Controller Communication Relationship (Direct Data Exchange)
Media-redundant transmission is configured for each address area between sender and receiver.
Requirements
• A topology with two independent paths has been configured. • A redundancy manager has also been configured.
Procedure
1. Double-click "Interface Submodule" for the IO controller (e.g. IF1). 2. Select the "Receiver" tab.
3. Create a new row ("New" button) and assign a sender to the receiver.
4. In the "Receiver Properties" dialog box, select the "Media Redundancy" check box.