Instruction manual

Instruction Manual
760006-A
September 2001
Rosemount Analytical Inc. A Division of Emerson Process Management Appendices 11-17
Model NGA 2000 Platform
Installation
If this I/O Module is received as a sepa-
rate unit, carefully examine the shipping
carton and contents for signs of damage.
Immediately notify the shipping carrier if
the carton or contents is damaged. Retain
the carton and packing material until all
components are operational.
To install this I/O Module, follow general
installation guidelines in Section 2 and
then do the following:
Autocalibration Sequence
Setup - Overall Timing
The calibration sequence is; wait until the
calibration time; indicate a calibration se-
quence; purge with zero gas; tell the
Analyzer to zero itself; wait until it says it’s
done; purge with the first span gas; tell
the Analyzer to change range (if neces-
sary); tell the Analyzer to span this range;
wait until it says it’s done; purge with the
next span gas and repeat up to a total of
four spans; purge with sample gas; indi-
cate the calibration sequence is over.
Before setting these parameters, make
sure the system clock is set correctly.
This is to be found in Technical level con-
figuration…, System setup…, Date and
time….
1. Enter the Main menu
2. Enter Expert controls and setup...
3. Enter Auxiliary module setup...
4. Select the Auto cal module
5. Select Timing parameters…
Set the day of the month, and the time of
day to start the calibration sequence. The
unit will automatically calibrate thereafter
at a suitable period set below. Make sure
you have chosen a day and time in the
future! Otherwise it will wait a month.
Set the calibration cycle period. This is
the length of time it will wait between cali-
brations. 24 hours is traditional, but it can
be programmed up to 255 hours. You can
set it to zero at this period, but to span
only every so many zeros, see below.
Set the zero gas dwell time. It should be
long enough that the Analyzer reaches a
good stable zero point. If in doubt make it
longer.
Set the span gas dwell time. This has to
be long enough for the Analyzer to be-
come stable at the span point. This time is
normally shorter than the zero time.
Set the sample gas dwell time. This is the
time it will wait after its last span before
releasing the “In Calibration signal” (either
the relay or the PROCESS variable). This
time should be long enough to allow the
reading to get to within its error tolerance
of the actual reading, normally shorter
than the other two times.
Set the control status. This module can be
slaved to another Autocalibration module,
or it can be a master for a group of two or
more such modules, or it can be inde-
pendent of them. If it is a master, it will
make all the other slaves start a calibra-
tion when this one does: if a slave it will
wait until it is told to calibrate before doing
so. If independent it will ignore any other