Hi. = High limit (for heating process) Lo. = Low limit (for cooling process)

Hi.Lo = High and low limit (for special process)

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

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

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 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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Omega Vehicle Security CN3271 Series manual Hi.Lo = High and low limit for special process, C2 = Rearming Mode