About the DRAS Network

The DRAS Network is the top-level container component for the DRAS client in a NiagaraAX station. You can add the DRAS network from the “Driver Manager” view, using the New button. You can also copy the DRAS network from the “dras” palette onto Drivers node in the nav tree.

The DRAS Network component has most of the typical properties that other network components share. For more details about the common properties, see “Common network components” in the NiagaraAX Drivers Guide.

In addition to the common properties, note the following properties:

• Rest Url

  This property has special importance because it represents the secured URL to connect to the DRAS server. The connection uses the Representational State Transfer (REST) software architectural style.

• Ssl Port

  Port 443 is designated for standard SSL communications.

• Dras Server Connection Timeout

  This property specifies the maximum time to wait for a response after a basic message request before determining a failure.

• Work on Cache Enabled

  The purpose of this property is to provide a way to update point values when communication with the server is not available. Cached event op mode schedules are files that have been previously communicated to and stored in on the client. When set to true, this property allows for the use of these cached values. Cached values are used at an interval set by the Work on Cache Frequency value.

• Work on Cache Frequency

  This is the frequency at which the cached schedule values are used.

• DRAS Network status

  As with most “field bus” drivers, the status of a DRAS Network is either the normal “ok” or less typical “fault” (fault might result from a licensing error). The Health property contains historical timestamp properties that record the last network status transitions from “ok” to any other status. The “Fault Cause” property further explains any fault status.

• DRAS Network monitoring

  The DRAS Network’s monitor routine verifies child DRAS Client component(s)—the “pingable” device in the DRAS driver. For general information, see “About Monitor” in the NiagaraAX Drivers Guide.

• DRAS Network views

  The DRAS Network’s default view is the DRAS Device Manager, equivalent to the Device Manager in most other drivers. You use this view to add DRAS Device components to the station. About the DRAS Device Manager view Other standard views are also available on the DRAS Network. However, apart from the DRAS Device Manager, you typically access only its property sheet