Vaisala Indigo200 - Relay Activation and Hysteresis Examples; Figure 19 Behavior of Relay that Activates above Limit, with Hysteresis

When hysteresis is used, the relay activates at the defined limit, but does not switch o
immediately when the measurement moves back to the other side of the activation limit.
Instead, with hysteresis, the relay remains active until the measurement crosses the relay
activation/deactivation limit and the additional buer value.
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Figure 19 Behavior of relay that activates
above limit, with hysteresis
1 Measurement goes above the relay
activation limit (solid line —) and the
relay activates.
2 Measurement falls below the activation
limit, but stays above the hysteresis
limit (dashed line - - -). The relay
remains active.
3 Measurement falls below the hysteresis
limit and the relay switches o.
6.1.3 Relay activation and hysteresis examples
Figure 20 (page 36) shows examples of dierent relay setpoint options, ranging from only
one setpoint to dierent combinations of "above" and "below" setpoints. The eect of
hysteresis is also described in the examples.
Chapter 6 – Configuring relays
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