Setting relay activation limit using hysteresis - INDIGO200SERIES - INDIGO202

Indigo202 User Guide

Document code
Content type
Product description
Product description > Features
Product description > Functions
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 reaches the defined tolerated variation limit.
Figure 1. Relay settings example: one setpoint with hysteresis
To define a single setpoint for relay activation when the measurement falls below the defined activation limit (Activate below) using hysteresis:
  1. Select to access Insight main menu.
  2. In the Configure Device menu, select either relay A or relay B.
  3. Enable the relay output by setting Relay output on/off to ON.
  4. Select the measurement parameter that is used to control the relay with the Output parameter dropdown.
    The parameter options depend on the connected probe. Note that the parameter units are defined in the Settings menu: see Unit settings.
  5. Enter the activation limit value in the Activate below field.
  6. Leave the Activate above field empty.
  7. Enter the hysteresis value in the Hysteresis field.
  8. Select the Error output state for the relay.
  9. Select Save to store the configuration.
    With this configuration, the relay activates when measurement falls below the value entered in the Activate below field (100 ppm in this example). When the measurement returns above the Activate below limit, the relay does not switch off until it has reached the combined value of the activation limit and hysteresis buffer (120 ppm in this example). For further examples on the effect of hysteresis, see Figure 1.