14.1Data Transfer

The DATA Transfer function used to transfer data from one PLC or automation device to another. This is especially useful in single-master protocols or to exchange data between devices that have different communication protocols and are unable to communicate with each other directly.

The Data Transfer function allows you to designate pairs of tags in the WebAccess to "transfer" data from the source to the target tag.  With Data Transfer feature configured, the WebAccess SCADA node "reads" data from the source tag, then "writes" this data to the Target tag. The Data Transfer function saves the user the effort to write scripts to do the same thing.

Each tag pair consists of a source tag and a target tag such that the value of the source tag is automatically transferred to the target tag. The values of the two tags are compared against a deadband.  If the difference in values exceeds the deadband, the target tag is updated.  This minimizes traffic on the network. The frequency of checking is set from 500 milliseconds to 60,000 milliseconds (½ second to 1 hour) for each tag pair.

With the Data Transfer, both points must reside on the same SCADA node.