niagaraDriver-NiagaraProxyExt

This component is an implementation of BProxyExt and applies to controller stations. An alternative for Supervisorstations exists among the virtual components.

Figure 66. ProxyExt properties

To view these properties, expand Config > Drivers > NiagaraNetwork > NiagaraStation, right-click Points, click Views > AX Property Sheet, expand a point and double-click its Proxy Ext.

Property	Value	Description
Device Facets	additional properties	Determines additional parameters to config facets.
Conversion	drop-down list	Defines how the system converts proxy extension units to parent point units. `Default` automatically converts similar units (such as Fahrenheit to Celsius) within the proxy point. NOTE: In most cases, the standard `Default` conversion is best. `Linear` applies to voltage input, resistive input and voltage output writable points. Works with linear-acting devices. You use the Scale and Offset properties to convert the output value to a unit other than that defined by device facets. `Linear With Unit` is an extension to the existing linear conversion property. This specifies whether the unit conversion should occur on “Device Value” or “Proxy Value”. The new linear with unit convertor, will have a property to indicate whether the unit conversion should take place before or after the scale/offset conversion. `Reverse Polarity` applies only to Boolean input and relay output writable points. Reverses the logic of the hardware binary input or output. `500 Ohm Shunt` applies to voltage input points only. It reads a 4-to-20mA sensor, where the Ui input requires a 500 ohm resistor wired across (shunting) the input terminals. `Tabular Thermistor` applies to only a Thermistor input point and involves a custom resistance-to-temperature value response curve for Type 3 Thermistor temperature sensors. `Thermistor Type 3` applies to an Thermistor Input point, where this selection provides a “built-in” input resistance-to-temperature value response curve for Type 3 Thermistor temperature sensors. `Generic Tabular` applies to non-linear support for devices other than for thermistor temperature sensors with units in temperature. Generic Tabular uses a lookup table method similar to the “Thermistor Tabular” conversion, but without predefined output units.
Tuning Policy Name	drop-down list	Selects a network tuning policy by name. This policy defines stale time and minimum and maximum update times. During polling, the system uses the tuning policy to evaluate both write requests and the acceptability (freshness) of read requests.
Read Value	read-only	Displays the last value read from the device, expressed in device facets.
Point Id	read-only	Reports the point ID.
Subscription Status	read-only	Reports the subscription status of the component.
Out	read-only	Provides a current value, facets and status. The value depends on the type of control point. Facets, which define how the value displays, including the value’s number of decimal places, engineering units, or text descriptors for Boolean/enum states. The current status of the data item, meaning the health and validity of the value. Status is specified by a combination of status flags, such as `fault`, `overridden`, `alarm`, and so on. If no status flag is set, status is considered normal and reports `{ok}`.