Instruction manual

Instruction Manual
760006-A
September 2001
11-22 Appendices Rosemount Analytical Inc. A Division of Emerson Process Management
Model NGA 2000 Platform
c. System Autocal I/O Module
Description
The System Auto Calibration I/O Module
allows the user to automatically calibrate
up to four Analyzer modules at once. A
typical application would be a CEMS-type
calibration for all Analyzer modules at
once, in sequence or in varied combina-
tions.
Four calibration cycles (software config-
urable) 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 software 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 Analyzer modules. The sev-
enth relay indicates an in-calibration con-
dition on the network. Here are the relay
output definitions:
• Relay 1 - sample bypass: closed when
the sample should not be flowing
through the Analyzer module.
• Relay 2 - zero gas: closed when the
zero gas should be flowing.
• Relay 3 - calibration in progress: closed
when any zero, span or calibration cycle
is being executed.
• Relay 4 - span gas 1: closed when span
gas 1 should be flowing.
• Relay 5 - span gas 2: closed when span
gas 2 should be flowing.
• Relay 6 - span gas 3: closed when span
gas 3 should be flowing.
• Relay 7 - span gas 4: closed when span
gas 4 should be flowing.
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 setup in the Analyzer module
• Line 2 - currently unused
• Line 3 - complete up to four (4) cycles,
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
After calibration, the output signal is then
corrected for zero and span. The System
Auto Cal I/O does not provide an analog
signal output. (See Table 11-7 for a com-
plete list of functions.)