Instruction manual

Instruction Manual
760006-A
September 2001
11-2 Appendices Rosemount Analytical Inc. A Division of Emerson Process Management
Model NGA 2000 Platform
Alarm Description – v2.2
This section describes the alarm capabil-
ity in V2.2. V2.3 added some significant
features which are described in the next
section.
There are three alarm relays each of
which may be programmed to respond to
any of the following categories.
• Concentration
• Warning
• Failure
• Control Status
• Validity
Concentration alarms respond to the
Analyzer primary reading, its measured
gas concentration. The alarm can be set
to trigger above or below a set point, and
the relay can be set to operate in normal
or fail-safe (powered when in the normal
state) operation. The set point may be
expressed either as an absolute value, or
as a percent of the current range, in which
case the concentration at which it alarms
will depend on the range.
The alarm deadband may also be pro-
grammed with an upper limit of 20% of
fullscale.
ITEM FUNCTION NOTES
Output Analog, 0 to 5 V, 0/4 to 20 mA
Supports auto-range changing, or independent
rage selection from that of Analyzer.
Alarm relay 1 Programmable function SPDT
Alarm relay 2 Programmable function SPDT
Alarm relay 3 Programmable function SPDT
Alarm relay 4 Powered when output on range 1 SPST
Alarm relay 5 Powered when output on range 2 SPST
Alarm relay 6 Powered when output on range 3 SPST
Alarm relay 7 Powered when output on range 4 SPST
Input line 1 High sets range to 1
Input line 2 High sets range to 2
Input line 3 High sets range to 3
Input line 4 High sets range to 4
Input line 5 No action
Input line 6 No action
Table 11-1. Available Functions – Analog Output with 3 Alarms (v2.2)