23-3
IM WT1801-01EN
23 Other Features
Enabling and Disabling the NULL Feature (NULL)
• Enable the NULL feature. The NULL key illuminates. The NULL indicator illuminates as described below
depending on how the Target Element setting has been set.
• All:
The NULL indicator illuminates in the upper right of the screen.
• Select: The NULL indicator illuminates to the left of the element, motor or AUX inputs, which are located on
the right side of the screen.
All
Select
NULL
indicator
NULL
indicator
• If you press NULL while the NULL feature is enabled, the NULL key light and NULL indicators turn off, and the
NULL feature is disabled.
• To make accurate measurements, we recommend that you execute zero-level compensation before
enabling the NULL feature.
• The NULL feature is disabled when:
• The power is turned on.
• The settings are initialized.
• A setup data file is loaded.
• You switch between direct current input and external current sensor input.
• You change the Sense Type setting for the Speed or Torque motor evaluation input signal.
• If the NULL feature is enabled or disabled while the display is held, the NULL indicator will illuminate or
turn off, but the held data will not be affected. Also, the NULL indicator will be highlighted.
• The DC values that the NULL value is based on when the NULL feature is ON are held, but the upper limit
of the NULL value is ±10% of the range when the crest factor is set to CF3. The upper limit of the NULL
value is ±20% of the range when the crest factor is set to CF6.
• When the range is changed, the NULL value upper limit will be determined by the new range. The NULL
value upper limit will also be adjusted when the range is decreased by the auto range feature.
Clearing Remote Mode (LOCAL)
Use this key to switch from remote mode (the REMOTE indicator will illuminate) to local mode (in which front
panel key operations are valid). This key is invalid when the WT1800 is in local lockout mode.
Key Lock (KEY LOCK)
When you enable the key lock, the WT1800 behaves as described below. You can use the key lock to prevent
unintentional operations.
• All key operations are disabled except for those of the power switch and SHIFT+LOCAL (KEY LOCK).
• The key lock indicator (“LOCK”) appears in the upper right of the screen.
The key lock remains on or off even after the power is turned off.