Instruction manual

Instruction Manual
760006-A
September 2001
Rosemount Analytical Inc. A Division of Emerson Process Management Description and Specifications 1-3
Model NGA 2000 Platform
The LON I/O Module boards allow for external
LON connections to the Platform.
Components that comprise the Platform and the
I/O Modules can be assembled in other configu-
rations depending on user needs.
NOTE
The Platform controller board software
must be of a later major revision than
any Analyzer module software. For
example, a V2.2 Platform controller
board will work with V2.2.1 Analyzer
modules, but not with V2.3 Analyzer
modules. The ".1" after the V2.2 refers
to a minor revision, which is compati-
ble with the V2.2 Platform controller
board software.
NOTE
It is strongly recommended that you
note the actual software revisions that
you have. Service or support people
will be able to diagnose any problem
you may have more easily if this in-
formation is immediately available.
The revision is marked on each com-
ponent, as well as noted in their Manu-
facturing data menus.
1-4 THE LON – THE NGA DIGITAL COMMUNI-
CATIONS NETWORK
The NGA 2000 Digital Communications Network
operates over a bi-directional, peer-to-peer, two-
wire system at a rate of 78 kbps. Modules are
connected with RJ-45 modular connectors and
UL level 4, 100 Ohm LAN cable. This means
that there is a single wire connection between
all the modules on the network. It plugs into
each module using a plug much like standard
telephones use. (In fact the wiring is not critical,
plain wire connections will work well over rea-
sonably short distances such as 100 feet.)
The network utilizes LONWORKS®, an open
control networking technology developed by the
Echelon Corporation. This uses the
LONTALK™ protocol. The combination of the
NGA 2000 modular architecture with the robust
LONTALK™ protocol allows the capability to
“multi-drop” nodes to create a distributed net-
work. This is to say that it is possible to connect
many devices onto the same network, and the
network protocol keeps everything working
without conflicts.
Every Analyzer modules or I/O Module node
that communicates to the network contains a
NEURON CHIP. This chip integrates three mi-
croprocessors, ROM, RAM, and EEPROM
memories, timers, multifunctional I/O, and the
network interface. From the user perspective
the inner complexities of the LON are thor-
oughly hidden from view and can safely be ig-
nored.
The network is self-installing upon startup. The
Platform acts as a Network Manager, assigning
addresses and generating its own database
automatically. Manual intervention is only
needed to determine linkages (“binding”) be-
tween Analyzer modules and I/O Modules. This
means that all you have to do is to connect eve-
rything and power it up, and then tell it which I/O
Module is connected to which Analyzer. Once
this has been done once, it never needs to be
done again unless modules are exchanged or
added.
Each NGA 2000 Analyzer module transmits
over two hundred pieces of data (called vari-
ables) that are characteristic of its specific gas
detection methodology. In addition to the main
reading - the primary or process variable (gas
concentration), many other parameters and
pieces of diagnostic information are available.
This data includes:
• Manufacturing data such as serial
number and software revision
• Configuration setup for calibration
control, component temperature
and other alarm set points, and
linearization parameters
• Operational status conditions such
as faults and calibration
• Secondary variables such as type
of gas measured, flow, tempera-
ture, and pressure readings
• Historical data such as known
good calibration values and factory
configuration settings