Integrating Xenta programmable controllers into a Niagara R2 UNC-520 Controller

[Product_Support]

Issue

Since both products -- Xenta programmables and the UNC 520 -- speak LON protocol, there is some assumption that integration should be seamless.  In the case of ASCs, this is true, but Xenta programmable controllers use some forms of proprietary communication that can complicate the integration.

Product Line

TAC IA Series, TAC Vista

Environment

• Xenta programmables
• Xenta 280, 281, 282, 283, 300, 301, 302, 401, 401:B
• UNC-520
• Niagara
• Tridium

Cause

Xenta programmables use proprietary communications for three main purposes:

1. To communicate their online status between group members and group masters
2. To communicate between a base unit and associated I/O modules
3. To pass proprietary TAC Network Variables between two programmable controllers

In a UNC-520, the first function would be taken over by the new network manager (Local Lon Device).  However, the second two must use Group Bindings set through a Vista compatible network management tool like LonMaker or NL220.  If the controllers are commissioned into the UNC-520, that communication will be broken and I/O modules will go offline and no network variables will pass.

Resolution

 It is possible to engineer a TAC Vista network as usual, using an LNS management tool to create group bindings to facilitate proprietary communications.  A UNC-520, set to non-network management mode could then be implemented on top. However, any attempt to commission the devices into the UNC-520 network will break that proprietary communication.  To prevent this scenario from occurring, the simplest method is:

1. Do not use proprietary TAC Network Variables to pass data between controllers.
   1. Use only SNVTs which will be available to a third party LON network manager like the UNC-520
   2. Make no SNVT bindings in a temporary LonMaker or NL220 database.  Let the UNC-520 handle all network management duties.
2. Do not define Xenta I/O modules in the Menta Device Specification.
   1. Use only Xenta 421A, 422A, 451A and 452A I/O modules.  These have the capability to act as stand-alone LON nodes.
   2. Define the modules as LON nodes, configure them using Configuring inputs on Xenta 421A or 451A when using the controller as a stand alone Lonworks node.
   3. Bind to the inputs and outputs of the I/O modules in the UNC-520.