Instruction Manual
748275-F
September 2003
Rosemount Analytical Inc. A Division of Emerson Process Management System Auto Calibration I/O Module 4-1
Model NGA2000 I/O Modules
SECTION 4
SYSTEM AUTO CALIBRATION
4-1 OVERVIEW
See Section 1 for information that applies to
all I/O Modules.
The System Auto Calibration I/O Module al-
lows the user to automatically calibrate up to
four Analyzer Modules at once. A typical ap-
plication would be a CEMS-type calibration for
all Analyzer Modules at once, in sequence or
in varied combinations.
Four calibration cycles (software configurable)
can be executed:
• manually-initiated zero cycle
• manually-initiated span cycle
• manually-initiated auto calibration cycle
(zero and up to four span functions)
• time-initiated auto calibration cycle
(based on the network's clock)
Up to four span solenoid valves and one zero
solenoid valve (customer supplied) can be
triggered at set time intervals. The frequency
and duration of the calibration cycle is soft-
ware programmable, allowing many varied
sequences, a few of which follow:
• zero x times, then span
• zero, then span
• zero, span, then check on a midpoint
Four SPST and two SPDT relays are used to
drive solenoid valves that control the flow of
zero and span calibration gases to the Ana-
lyzer Module. The seventh relay indicates an
in-calibration condition on the network. Relay
output definitions follow:
• Relay 1 - span gas 1: closed when span
gas 1 should be flowing
• Relay 2- span gas 2 closed when span
gas 2 should be flowing
• Relay 3 - span gas 3: closed when span
gas 3 should be flowing
• Relay 4 - span gas 4: closed when span
gas 4 should be flowing
• Relay 5 - span gas 5: closed when zero
gas should be flowing
• Relay 6 - calibration in progress: closed
when any zero, span or calibration cycle
is being executed
• Relay 7- sample bypass: closed when
the sample should not be flowing
through the Analyzer Module
The System Auto Cal Module has six digital
input lines for remotely initiated calibration.
The function of each line is the following:
• Line 1 - do zero calibration on current
range as set up in the Analyzer Module
• Line 2 - currently unused
• Line 3 - complete zero and span cycle
as programmed
• Line 4 - local/remote selection: 0 = local,
1 = remote (used to set the dwell times
for gases)
• Line 5 - currently unused
• Line 6 - Calibration or QC check: 0 = as
setup in the Auto Cal Module, 1 = QC
check only
Characterizations for pins 5 through 18 in Fig-
ure 1-5 (relative to SPDT or SPST and NC, C,
NO or C) remain accurate, but pin assign-
ments relative to specific relays are different
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