Warning
Electrostatic Discharge Required: Always discharge static electricity from your person by touching metal prior to handling any hardware. Failure to do so may result in damage to devices.
Issue
Introducing a previously commissioned Continuum IOU module such as an AC-1 to an Access Expert or Security Expert site can cause communication issues in the LON bus due to duplicated node id.
Product Line
Andover Continuum, Security Expert, Access Expert
Environment
Continuum AC-1
Continuum Net Controller
Continuum Net Controller II
Access Expert Controller
Security Expert Controller
Cause
When IOU modules are commissioned in a Continuum system, the Net Controller assigns each module a Node ID, this is in addition to the LON Module ID that is unique to each module hardware, the purpose of the Node ID, is to decouple the identifier used by Continuum for communication from the specific piece of hardware, this in order to facilitate the replacement of a failed module without the need to change its Continuum identifier. The module stores the Node ID in nonvolatile memory so that it persists across power loss.
If a Continuum IOU module is introduced to a LON network (Security Expert SP-AC1 or Access Expert AX-SSC) without clearing its Node ID, there is a risk of creating a duplicate Node ID condition that will prevent the LON network from operating properly.
IMPORTANT
This should not be an issue during the normal transition of Continuum site to Security Expert or Access Expert, as all the modules on the running LON bus should have unique Node IDs, this is only a problem when adding a module, or replacing a module with one that has been used before.
Resolution
In order to signal its presence on the LON network, each module will transmit on resetting its status network variable. If upon receiving this message, the Net Controller determines that the module is NOT in its local database, the controller will decommission the module by setting its Node ID to zero.
Before introducing a Continuum IOU module that has been previously commissioned to the LON network of an SP-AC1 or SX-SSC controller, decommission the IOU module using the steps below:
Attach the module to an empty Net Controller that is powered down with its battery removed. For a Net Controller II, in order to be absolutely sure that the Net Controller has an empty database, you may need to clear its backup in flash from a browser or by the use of the reset IP switch. See LL on how to use the controller's reset IP switch to clear its flash backup https://community.exchange.se.com/t5/Building-Automation-Knowledge/How-to-clear-the-controller-flash-backup-from-the-hardware-using/ta-p/5877
Power up the Net Controller
Once the CPU led on the Net Controller starts blinking, press the 'Reset' button on the IOU module.
Wait 30 seconds to make sure the decommissioning process has completed.
Power down the Net Controller
Remove the IOU module
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