Omega Engineering CN3271 Series User Manual page 14

Hi. = High limit (for heating process)
Lo. = Low limit (for cooling process)
Hi.Lo = High and low limit (for special process)
C2 = Rearming Mode C2 = Rearming Mode C2 = Rearming Mode
C2 = Rearming Mode C2 = Rearming Mode
O = Acknowledgements rearm (reset) the limiter (and
restart the process) only if the condition which
generated the shutdown status no longer exists
(points A and C of the Example 1). It do not
generate any effect if the condition which
generated the shutdown status still exists (point
B of the Example 1).
I = Acknowledgements enable the automatic
rearmament (reset) of the limiter if the
condition which generated the shutdown
status still exists (point B of the Example 2).
(The instrument rearms (reset) automatically
when the condition which generated the
shutdown status no longer exists).
Notes about limiter function Notes about limiter function Notes about limiter function Notes about limiter function Notes about limiter function
The relay of the output 1 operates in fail-safe mode
(relay de-energized during shutdown condition) and
latching mode.
The OUT 1 turns OFF when:
- C1 = Hi and the measured value is greater than
limiter threshold ["Su" parameter (see Operative
parameters")] or
- C1 = LO and the measured value is less than
limiter threshold ["Su" parameter (see Operative
parameters")] or
- C1 = HiLO and the measured value is greater
than "Su" parameter (see Operative parameters")
or less than "S1" parameter (see Operative
parameters").
The Out 1 remains OFF until the condition which
LHL-1-NEUTRO.pmd 11
generated the shutdown, no longer exists and the
acknowledge action has been performed.
The upper display flashes during a shutdown and
returns to a steady display when the shutdown
condition no longer exists.
When C2 = 0 and OUT 1 is OFF, the RESET LED is
ON.
When C2 = 1 one of the following condition may
not not
not not occur:
- if no acknowledgement has been made, OUT 1 is
OFF and the RESET LED is flashing;
- if the acknowledgement has been made but the
condition which generated the shutdown status
still exists, OUT 1 is OFF and the RESET LED is
steady ON.
The shutdown condition can be stored in
permanent memory (see C4).
Acknowledgment can be performed by pressing
the RESET key, by momentarily closing the
external dry contact or by a command from the
serial link.
The length of the shutdown condition and max/min
measured values are stored in memory and
available for viewing until the next shutdown
condition occurs.
These informations are lost at power down.
During a shutdown condition the max/min
measured values are continuously updated and
can be monitored.
Example 1 - C1 = Hi and C2 = O
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19/04/2004, 15.07