User`s guide

LONWORKS FTT-10 Transceiver User’s Guide 6-3
Two or more FTT-10A transceivers can function as a physical layer repeater to
extend the size of the network. The standard channel definition shown in table
6.2 accommodates the delay that occurs as a packet is forwarded by a single
physical layer repeater. If additional repeaters will exist in the path of a packet,
the Rcv Start Delay, and Missed Pream parameters for the channel definition
must be modified according to the notes shown in table 6.2. As the number of
physical layer repeaters increases, the overall channel capacity is reduced
because the inter-packet spacing is increased. In high traffic applications,
LONWORKS routers should be used to selectively forward packets. Systems
designed using LONWORKS routers instead of physical layer repeaters will have
a higher overall network packet capacity. For channels with no repeaters,
channel performance can be improved by adjusting these parameters with N= 0.
Warning: Other parameter variations may be possible but require schematic or
other changes; contact Echelon Technical Support for more information. It is
important to use the standard channel definition to achieve LONMARK
interoperabiity.
The LonBuilder Developer’s Workbench is initially used to develop and debug
applications on emulators. Once application testing on the emulators is
completed, the LonBuilder software is used to generate custom system images for
the actual target hardware (see the LonBuilder User's Guide, Chapter 7, and the
Echelon Engineering Bulletin LONWORKS Custom Node Development).
A LonBuilder Router with a LonBuilder SMX Adapter and FTM-10 Modular
Transceiver is typically used to interface the LonBuilder hardware to a TP/FT-
10 channel. When changing the LonBuilder hardware configuration to attach a
LonBuilder router to a TP/FT-10 channel, ensure the following steps are
completed:
• Select a backplane channel for side A and a TP/FT-10 channel for side B in
the LonBuilder Router Target HW definition;
• Ensure that channel A of the router is connected to the backplane channel.
For level 1 and 2 routers, a backplane transceiver must be installed in the
router P2 channel A transceiver expansion connector. For level 3 routers,
JP1 must be in the "B" position;
• Mount an FTM-10 Modular Transceiver on a LonBuilder SMX Adapter;
• Mount the LonBuilder SMX Adapter on the router P3 channel B transceiver
expansion connector. For level 3 routers, JP2 must be in the "A" position;
• Create a router node specification for the LonBuilder Router;
• Use the LonBuilder tool to install and load/start the router.
A heavily loaded TP/FT-10 channel may generate more traffic than can be
forwarded through the LonBuilder Router. This may cause the LonBuilder
Protocol Analyzer to miss some of the packets on the TP/FT-10 channel. To
ensure that the protocol analyzer receives all packets, it must be directly attached
to the TP/FT-10 channel. This allows the protocol analyzer to monitor all
channel traffic. When changing the LonBuilder hardware configuration to
attach the protocol analyzer to the TP/FT-10 channel, ensure that the following
steps are completed: