Virtual Units Example

The following example shows the implementation of virtual devices on a primary and standby server.

The primary server, which hosts the virtual device "Virtual DevP", has the following Citect.ini parameter settings:

[DNPR]
EnablePeerRedundancy = 1
LocalAddress = 10.176.234.11
LocalPort = 5200
PeerAddress = 10.176.232.61
PeerPort = 5200

[IOServer]
WatchDogPrimary = 1

The standby server, which hosts the virtual device "Virtual DevS", has the following Citect.ini parameter settings:

[DNPR]
EnablePeerRedundancy = 1
LocalAddress = 10.176.232.61
LocalPort = 5200
PeerAddress = 10.176.234.11
PeerPort = 5200

[IOServer]
WatchDogPrimary = 1

In the following diagram, the virtual device and the I/O devices are communicating on the same port. The three devices are active and online on the primary I/O server. The 3 devices are inactive on the standby I/O server. The I/O devices can be controlled by the virtual device.

In the diagram below, the virtual device and the I/O devices are communicating on the same port. The I/O device was usurped onto the standby I/O server. The virtual device and I/O device 1 are active and online on the primary I/O server. I/O device 1 can be controlled using the virtual device.

I/O device 2 is active and online on the standby I/O server. The I/O device 2 cannot be controlled with the virtual device because they are not active on the same I/O server.

In the next diagram, the virtual device and the I/O devices are communicating on the same port. The connection of the port has been interrupted and the devices are automatically usurped onto the standby I/O server. The three devices are active and online on the standby I/O server. Both I/O devices can be controlled by the virtual device.

In the diagram below, both I/O devices are communicating on the same port. The global virtual devices are on a different port than the I/O devices, and both global devices are primary devices.

The primary global virtual device 1 is active and online on the primary I/O server. The primary global virtual device 2 is active and online on the standby I/O server. Both I/O devices are active and online on the primary I/O server and can be controlled by the global virtual device 1 on the primary I/O server.

In the last example, both I/O devices are communicating on the same port. The global virtual devices are on different ports to the I/O devices and both global devices are primary devices.

The primary global virtual device 1 is active and online on the primary I/O server. The primary global virtual device 2 is active and online on the standby I/O server. I/O device 2 was usurped onto the standby I/O server. I/O device 1 is active and online on the primary I/O server and can be controlled by the global virtual device 1 on the primary I/O server.

I/O device 2 is active and online on the standby I/O server and can be controlled by the global virtual device 2 on the standby I/O server.

See Also

Virtual Units Configuration

Configuring Variables for Virtual Units