Relay hysteresis - INDIGO201 - INDIGO200SERIES - INDIGO200

Indigo201 User Guide

Document code
M212842EN
Revision
A
Language
English (United States)
Product
INDIGO201
INDIGO200SERIES
Document type
User guide

If the measurement you are using to control the relay is likely to move back and forth close to the activation setpoint, you can set a hysteresis that prevents the relay switching on and off too frequently.

When hysteresis is used, the relay activates at the defined limit, but does not switch off 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 buffer value.

Figure 1. 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 off.