Reference Manual
748384-C
September 2003
Rosemount Analytical Inc. A Division of Emerson Process Management I/O Modules Variables
3-3
NGA2000 Reference
ALVAR
Direction output
Binding
None
Type
3-element enumerated array
Value range
VALIDITY; AM Warning; AM Failure; Sys. Failure; Control Status; Concentration;
Analyzer alarm 1; Analyzer alarm 2; Analyzer alarm 3; Analyzer alarm 4; Analyzer
alarm 5; Analyzer alarm 6; Analyzer alarm 7; Analyzer alarm 8; Analyzer alarm 9;
Analyzer alarm 10.
Units None
Description
AIO only; determines the functionality of each relay.
Usage
VALIDITY makes the relay respond to the VALIDITY variable, it will alarm if
VALIDITY becomes anything greater than 0; AM Warning makes the relay respond
to the GENERALSTATE variable, it will alarm if GENTERALSTATE is equal to
"WARNING" (1); AM Failure makes the relay respond to the GENERALSTATE
variable, it will alarm if GENERALSTATE is equal to "FAILURE" or "SAFETY
FAELLTRE" (2 or 3); Sys. Failure makes the relay respond to SYSTEMSTATE, it
will alarm if SYSTEMSTATE becomes greater than 0; Control Status makes the
relay respond to the CONTROL variable, it will change state if CONTROL changes
between the values of 0 or 2, and I - i.e. it responds to remote versus local or
automatic control; Concentration makes the relay respond to the value of PVA, the
gas concentration, as determined by the concentration variables such as ALLVL,
ALTYPE etc.; Analyzer alarm I etc. Are not used in version 2.2.
See also
ALLVL
ALTYPE
AM_ALARM
Direction Input
Binding
None
Type
10-element enumerated array
Value range
OFF; ON
Units None
Description
An array of alarm reporting elements.
Usage
Analyzers supporting this feature can generate specific alarms that are assigned to
various elements of this array. If enabled through ALVAR, the 1/0 will cause its
appropriate relay to respond to any of these. No 2.2 analyzer supports this feature.
See also
ALVAR
AMFAIL
Direction output
Binding
None
Type Enumerated
Value range
ZERO; FULLSCALE; LAST VALUE
Units None
Description
AIO, ACAL only; describes what the analog output will do if the PVA is not updated
for more than 10 seconds.
Usage
If the analyzer dies, or for some reason the PVA variable is not updated, the
analog output may be forced to zero (or 4 mA), to full scale (5V or 20mA), or to
hold at its last value. This should be chosen based on the results of such a failure.
See also