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4.1    Network Communications

.1    Stand-Alone Panels (SAPs)

        .1     Provide a fully networked system of SAPs which use a peer-to-peer communications protocol to support the
               distributed control features as specified herein. Each SAP shall be connected directly to the network. Each
               SAP shall have equal network access priority and shall not require a separate interface panel (gateway) to
               accomplish network communications.

        .2    Provide a means to ensure communication integrity.

        .3    To prevent damage to the system each data highway line shall be provided with a means of isolation, either
               optically or by some other means.

        .4    Upon failure of the network to communicate information from one SAP to other SAPs, retain the last
               legitimate value of each point in the SAPs that require it, and continue to control the systems based on those
               values. Failure of any SAP , or any part of a SAP on the network, shall not affect the ability of the network to
               communicate among the remaining SAPs.

        .5    Each physical or virtual point shall have a user-definable, unique, system-wide logical point mnemonic. The
               format of this point mnemonic shall conform to BCBC Point Naming Convention. All point functions such as
               commands, overrides, trends, reports, logs and graphics shall only need to use this unique logical point

        .6     Values, status's and attributes of physical and software points from one SAP shall be available for use in any
               other SAPs. Any broadcast points, send-receive blocks or any other form of table or database that is
               required to initialize and accomplish this function shall be created solely, and automatically, by the operating
               system, without the need for operator intervention. Listings of physical and software points shall not include
               tables referred to in this paragraph.

.2    Terminal Unit Controllers (TUCs)

        For systems which include terminal unit controllers (TUC's).

       .1    TUC's shall be considered to be any panel connected to a sub-communication network, where access to the
               features and points of the TUC is only obtainable through the SAP to which the sub-network is connected.
               TUCs shall have a limited number of inputs and outputs, which are specifically designed to control one
               component serving a single thermostatic zone (e.g., VAV terminal unit, dual-duct terminal unit, fan-coil unit,
               zone heat pump, etc.).

        .2    The terminal unit controllers (TUCs) shall incorporate all of the requirements for the stand-alone panels
               (SAPs), except for peer to peer communications (
PS and auto-networking provisions (PS

        .3    The auto-networking requirements defined in PS for SAPs apply between the TUC and the SAP it is
               connected to. If the TUC is connected to the main peer to peer communication network, the full requirements
               of PS apply.

4.2    System Processing Speed

        .1    For multi SAP systems, the system processing speed is intended to address inter-SAP communications and will be
               checked during the commissioning phase by evaluating value updates from one SAP as received and displayed in
               another SAP . This will be done by setting up a display of all SAP counters and checking how frequently each
               counter is updated on the refreshed display on site.

        .2    Every counter shall show an updated value on the display within TWENTY (20) seconds of the previous update
               value appearing. This feature will be checked during the commissioning phase.

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