LonWorks Import Module

Module icon

Overview

The module takes a LonWorks input network variable and converts it to an ION register. As discussed below, the input network variable must be one of the standard network variable types (SNVTs) as specified by the SNVT setup register.

The LonWorks Import module, together with the LonWorks Export module, allows an ION meter to be integrated into a LonWorks network. Once you have imported data from another LonWorks-compatible device and converted it to ION, you can manipulate the data using the advanced features of your meter, thus extending the capabilities of the LonWorks network. Additionally, you can expand the I/O capabilities of your meter by adding LonWorks-compatible I/O devices.

Inputs

The input is a network variable from a LonWorks network. Each LonWorks Import module has one network variable associated with it.

Setup registers

SNVT

This register defines Standard Network Variable Type (SNVT) that the module imports. It indicates to the LonWorks Network Manager what kind of data the module is expecting. In effect, it associates a unit with the value. For devices on a LonWorks network to be logically connected, they must use the same data type (i.e. the same SNVT).

By specifying a particular SNVT, you are implicitly defining the kind of data the module will be handling. For example, if a device on the LonWorks network delivers a network variable representing temperature, and this is the value you want to convert to an ION register, you must set this setup register to SNVT_temp_f. For a detailed description of each SNVT, refer to LonMark’s SNVT Master List, or visit LonMark’s website at www.LonMark.org (note however that the LonWorks Import module only supports those SNVTs listed in its SNVT setup register).

Output registers

Netvar

This numeric register contains the value of the input SNVT (see the SNVT setup register description) accepted by the module.

BindState

This register indicates that the input network variable imported by the module is bound to at least one other output network variable.

Event

All events produced by the module are written into this register. Events mark changes to the SNVT setup register, input links, and the state of the BindState output register. The following information is stored for each ION event: time stamp, event priority (in this module, all events have a pre-defined priority of 10), the event’s cause, the event’s effect, and conditions associated with the event’s cause and effect.

Responses to special conditions

The following table summarizes how the module behaves under different conditions.

Detailed module operation

The figure below illustrates the operation of a LonWorks Import module. The LonWorks device delivers its data to the network in the form of an output network variable. The ION meter contains a LonWorks Import module whose SNVT setup register has been set to match the SNVT of the network variable.

The Network Manager recognizes the two devices and binds (performs the logical connection) between them. Thus, the data is imported from the LonWorks network, converted to an ION register and made available to the advanced features of the ION device.

You must create and configure all the LonWorks Import modules you plan to use before installing the device on the LonWorks Network. If you create any new LonWorks Import modules or you change their configuration, you will have to reinstall the device on the LonWorks Network for your changes to be detected.

Supported SNVTs

The ION7300-LONFT’s LonWorks Import and LonWorks Export modules support the following SNVTs: