Reference Manual
748384-C
September 2003
1-36 Introduction
Rosemount Analytical Inc. A Division of Emerson Process Management
NGA2000 Reference
1-19 SERIAL I/O MODULE
There is available in the platform a non-LON I/O
module that can produce up to 8 channels of
12-bit analog outputs, as well as 3 alarm con-
tacts and a serial (either RS232 or RS485) port.
a. Details
The serial I/O board is not a LON module
like the other I/O modules. It communicates
directly to the processor in the control mod-
ule. As a result its menus are not like those
in the single channel I/O modules.
Its analog outputs are arranged in groups of
two. Each output is available as both a cur-
rent and a voltage simultaneously, although
you can only calibrate one of these at a
time. Each output is isolated from the main
analyzer and control module ground, but
each pair has no isolation between them-
selves, they share a common ground with
each other.
You can add up to three more pairs of ana-
log output onto an serial I/O board. How-
ever you can only have one serial I/O board
in a system.
You can add a serial interface module to the
serial I/O board, configured either for
RS232 or RS485. You can then select
which interface protocol to use with this.
See the interface section of this manual be-
low for details.
You have to configure the serial I/O card
manually, telling it what modules have been
installed. Telling the computer the wrong
thing will degrade the response time of the
system, but will not cause a crash.
b. Troubleshooting
I configured the serial I/O module output
but nothing happens…
Verify that you do in fact have an serial I/O
card installed, remember that the menus
are there regardless. Also verify that you
have connected wires to the correct I/O
board, not to a normal I/O card.
Also, verify you have edited
Module in-
stalled
: to YES.
I set the serial I/O module up for Modbus
(or AK) and nothing happens…
Verify that you have the serial interface op-
tion installed. You have to do this by look-
ing at the board.
Also verify that you have selected the cor-
rect module type under
Type of installed se-
rial interface:
How do I configure the relay outputs of
the serial I/O module…
The relays are not configurable. They only
work as described above.
If you want to have concentration alarms
you need to use an analog I/O module.