Driver MultiPlexer Tags

Driver multiplexer (DriverMUX) tags allow you to set up redundant lines of communication between I/O tags and equipment.  Possible uses for this tag include:  

•    Establishing a fail-over communications route in the event that one system is lost.

In its basic configuration, the DriverMUX tag will direct all communications to the primary driver. In the event that the connection to the primary driver is lost, communication will switch to the secondary driver. 

•    Upgrading to new communications equipment/drivers with zero downtime.

In this scenario, you would install the new equipment and drivers while the existing system remains in place. The new drivers would be connected to the DriverMUX tag instead of directly to your I/O devices.  When you are ready to test the new system, you can direct the DriverMUX to switch to the new, secondary system. If there are problems, then communication will immediately and automatically switch back to the primary system with no loss of data.

•    Load sharing between two lines of communication.

The DriverMUX tag can be directed to use both communication drivers in either an alternating or an as-ready basis.  While one driver is busy with a large packet, the other can continue to send messages.

•    To provide OPC Server redundancy.

A DriverMUX tag may be configured with OPC Client Drivers as subordinates. This will allow I/O tags to exchange data with any number of OPC Servers.

The characteristics of the DriverMux tag are described in the table below.

DriverMux Characteristics

Tag Browser Name:               DriverMUX

Database Table Name:          DriverMUX

Type:                                       Driver

Tag Group Memberships:      Drivers, Numeric

Log Enabled Variables:          see Communication Driver Log-Enabled Variables

Native Drawing Methods:    see DriverMUX Tag Drawing Methods