Identifying common resources

There can be equipment in your plant that is not partitioned as part of a group, that is, a piece of equipment that operates entirely without other equipment to perform a task. In the DeltaV system, you still define these common resources as a unit. A unit can be a single piece of equipment or multiple pieces that work together as one unit.

When configuring your control or equipment module classes, you designate the common resource's ownership type as a shared.

A typical example of a common resource unit is a three-way valve. As illustrated in the following figure, the Base and Additive units share a three-way valve to transfer material into the Reactor unit. Once the valve is defined as its own unit in the DeltaV system, you can assign it as 'needed equipment' to the XFER_OUT phase. Using this configuration, the XFER_OUT phase will not start executing until it acquires the valve. If the valve is already acquired, the phase waits until the valve is available.

Three-way Valve as a Common Resource