Driver attributes

Each driver is enabled by a feature line (element) in the license file. Most of the drivers utilize the same attributes within that feature. The most common driver attributes are shown below.

<feature name="driverName" expiration="expirationDate" device.limit="none" history.limit="none" point.limit="none" schedule.limit="none">

The various "limit type" attribute values can be either "none" or a numerical (limit) value, for example device.limit=32. Note that a limit value of none means unlimited, whereas a limit value of 0 means none allowed.

For many drivers, only the point.limit and device.limit attributes are applicable; yet most drivers include all .limit attributes. For example, none of the Modbus-related drivers have any history or schedule import/export capability, due to the simplicity of the Modbus protocol. Thus, "history.limit" and "schedule.limit" values have no significance in the feature for a Modbus driver.

NOTE: In Niagara 4 (and depending on license), limit attributes in individual drivers may be superseded by “global capacity” limits, using a licensing model that sets limits that span across multiple drivers. This allows more flexibility to allocate the number of devices, points, and so on—without requiring ongoing license changes. For more details, see “Global capacity licensing”.

Driver attributes

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