TITLE
    LocalTalk Has Effective Electrical Isolation
Article ID:
Author:
Created:
Modified:
3688

5/11/89
5/11/89

TOPIC


DISCUSSION



    The LocalTalk system is much less sensitive to power problems than many
    networks.

    To start with, LocalTalk uses differential signaling, which has a higher
    noise immunity than normal, directly-connected TTL logic networks (like
    Corvus, for instance). Also, LocalTalk uses transformer coupling from the
    network to the node. This provides additional isolation from noise on the
    network. The transformer specification requires that there be no
    significant leakage current with 1000VDC applied between the secondary
    winding and the core.

    Because the LocalTalk network is passively coupled, any severe noise spikes
    would have to come through the system itself. This means any protection
    provided for the system itself would also be protecting the network.



EXTENDED Information section - Apple Internal Use - Service Providers and Support Professional


APPLE EYES ONLY Information section - Apple Need-To-Know Confidential


Article Change History:



Copyright © 2000 Apple Computer, Inc. All rights reserved.