VEGA FIBERTRAC 31 4 … 20 mA_HART - four-wire - Manual (Page 36)

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6 Set up with the display and adjustment module
FIBERTRAC 31 • 4 … 20 mA/HART - four-wire
40446-EN-131119
You can choose whether the sensor should output modulated current
(dithering) or the set fault current in case external radiation appears.
In the case of modulated measuring current (dithering), the last
valid current value is maintained and the current output modulates a
square-wave voltage ±1 mA around this value.
In this menu item you can activate the relay output and determine its
function as well as the switching points.
When the output of the process values is set, you can choose be-
tween overfill and dry run protection.
The relay outputs of the sensor react accordingly.
You can choose "no" reference value. In this case, the relay output
operates as fail safe relay.
•
None - Relay operates as fail safe relay
•
Electronics temperature
•
Process value
"No" reference value means that the relay output operates as fail safe
relay.
Push the [->] button, to reach the relay settings.
Example for the adjustment of the process value
First of all select the requested mode (overfill or dry run protection).
Caution:
Independent of the selected reference value, the relay will deenergize
in case of failure.
With this menu item you safeguard the sensor parameters against
unauthorized or unintentional modifications.
This menu item is described in the operating instructions manual
"Display and adjustment module".
Setup/Relay
Lock setup - adjustment