Example of over and under setpoint (standard) alarm operation
A setpoint condition occurs when the magnitude of the signal being monitored crosses the limit specified by the pickup setpoint setting and stays within that limit for a minimum time specified by the pickup time delay setting.
The setpoint condition ends when the magnitude of the signal being monitored crosses the limit specified by dropout setpoint setting and stays within that limit for a minimum time specified by dropout time delay setting.
Over setpoint
When the value rises above the pickup setpoint setting and remains there long enough to satisfy the pickup time delay period (ΔT1), the alarm condition is set to ON. When the value falls below the dropout setpoint setting and remains there long enough to satisfy the dropout time delay period (ΔT2), the alarm condition is set to OFF.
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A |
Pickup setpoint |
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B |
Dropout setpoint |
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ΔT1 |
Pickup time delay period (in seconds) |
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EV1 |
Start of alarm condition |
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ΔT2 |
Dropout time delay (in seconds) |
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EV2 |
End of alarm condition |
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ΔT3 |
Alarm duration (in seconds) |
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Max1 |
Maximum value recorded during pickup period |
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Max2 |
Maximum value recorded during alarm period |
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The meter records the date and time when the alarm event starts (EV1) and when it ends (EV2). The meter also performs any task assigned to the event, such as operating a digital output. The meter also records maximum values (Max1, Max2) before, during or after the alarm period.
Under setpoint
When the value falls below the pickup setpoint setting and remains there long enough to satisfy the pickup time delay period (ΔT1), the alarm condition is set to ON. When the value rises above the dropout setpoint setting and remains there long enough to satisfy the dropout time delay period (ΔT2), the alarm condition is set to OFF.
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A |
Pickup setpoint |
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B |
Dropout setpoint |
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ΔT1 |
Pickup time delay period (in seconds) |
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EV1 |
Start of alarm condition |
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ΔT2 |
Dropout time delay (in seconds) |
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EV2 |
End of alarm condition |
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ΔT3 |
Alarm duration (in seconds) |
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Min1 |
Minimum value recorded during pickup period |
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Min2 |
Minimum value recorded during alarm period |
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The meter records the date and time when the alarm event starts (EV1) and when it ends (EV2). The meter also performs any task assigned to the event, such as operating a digital output. The meter also records minimum values (Min1, Min2) before, during or after the alarm period.