Replacing devices – Echelon LNS User Manual

Page 146

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LNS Programmer's Guide

132

Read the SelfTestResults property of a LonMarkObject to

perform a self-test on the LonMarkObject:

Dim MyObjectStatus as LcaObjectStatus

Set MyObjectStatus = LonMarkObject.SelfTestResults

Does the test complete?

If not, an exception will be thrown.

Follow these steps:

Poll the SelfTestInProgress

property until it returns False.

Read the FailSelfTest property to

determine why the self-test failed.

If yes, the self-test will return an

ObjectStatus object.

Examine the properties of the

ObjectStatus object to see the

results of the self-test. See the LNS

Object Server Reference help file for

more information on these propertes.

Figure 6.3 Performing a Self-Test on a LonMarkObject

NOTE: The LonMarkAlarm object supports alarming on devices that implement their

alarms through SNVT_alarm network variables, but not through the more recent
SNVT_alarm2 type. However, SNVT_alarm2 type network variables can be monitored

and controlled using the standard monitor and control techniques described in Chapter 9

of this document.

To receive meaningful results for the SelfTestResults and Status properties of the
LonMarkObject, the device must support these features. If the device does not comply

with version 3.0 or later of the LonMark Application-Layer Interoperability Guidelines,

then the

LonMarkObjects

and

ConfigProperties

collections will be empty for the

device, and the properties mentioned in this section will be inaccessible.

Some devices that comply with version 3.0 or later of the LonMark Application-Layer
Interoperability Guidelines
may not support the self-test feature. Reading the
SelfTestResults property in this case will cause an exception to be thrown. You can

use the ReportMask property of the

LonMarkObject

object to determine whether a

device supports self-tests.

Replacing Devices

This section describes how to replace a device with a new device that contains the same

application image and external interface as the old one. Replacing a device in a

L

ON

W

ORKS

network is different than replacing a device in a hardwired system. You

cannot simply unplug the old device, and plug in a new one to take its place in a
L

ON

W

ORKS

network. You must transfer the network image (network address and

connection membership) from the old device to the new device. If the old device contained

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