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GMC-I Gossen-Metrawatt GmbH
4.4
Key Operation
Querying parameter values CT, VT and S
∅
Apart from the LCD test, the menu key located between
LCD and serial plate serves to query current paramter val-
ues and, in the case of active energy meters with special
features, to change parameters (provided that the enable
key has been activated before). The sequence can be seen
from the figure on the right.
If no key is pressed for 2 minutes, the display returns auto-
matically to the standard setting.
Parameters can be changed in the following instruments:
Parameters CT, VT for U138x with feature Q1,
parameters S
∅
for U128x/U138x with feature V2/V4
a) Enabling parameter modifications
The enable key serves to enable or disable paramter
changes. It is located below the terminal cover and is acti-
vated with a pointed object (e. g. ballpen).
Pressing the key for the first time activates operating mode
„Change parameters“ (key off):
Renewed activation disables operating mode „Change
parameters“ (key on):
If the key is not activated for approx. 2 minutes, operating
mode „Change parameters“ is automatically aborted and
blocked.
The key is displayed again:
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