Lake Shore Model 370 AC Resistance Bridge User’s Manual
4.18 LOCKING THE KEYPAD
The keypad lock feature prevents accidental changes to parameter values. When the keypad is locked most parameter
values may be viewed but only a few can be changed from the front panel. The temperature control heater can be turned
off but not changed in range and latched alarms can be reset when the keypad is locked.
A 3-digit code must be used to lock and unlock the keypad. The factory default code is
123
and it can only be changed
using a computer interface. If the instrument parameters are set to default values, the code is reset to the factory default.
The instrument parameters cannot be reset to default values from the front panel when the keypad is locked.
The following message will appear on the display if the user attempts to change a locked parameter.
Locked
NOTE:
The computer interface has a remote operation mode that may be mistaken for a locked keypad. If the display
shows the Remote annunciator on the top line, press the
Local
key to regain local control of the instrument.
To lock the instrument keypad press and hold the
Enter
key for 5 seconds. The following screen appears as a prompt for
the 3-digit lock code.
Enter Code To
Lock Keypad
Use the data entry keys to enter the 3-digit lock code (default 123). The instrument returns to the normal display with the
keypad locked.
To unlock the instrument keypad press and hold the
Enter
key for 5 seconds. The following screen appears as a prompt
for the 3-digit lock code.
Enter Code To
Unlock Keypad
Use the data entry keys to enter the 3-digit lock code (default 123). The instrument returns to the normal display with the
keypad unlocked.
4.19 DEFAULT PARAMETER VALUES
It is sometimes desirable to reset instrument parameters to their default values or erase the contents of user curve
memory. This data is stored in nonvolatile memory called NOVRAM. The instrument allows parameter and curve data
locations in NOVRAM to be cleared independently. Instrument calibration is not affected by this operation. Firmware
version dates for both main and input firmware are also displayed during this sequence.
To clear NOVRAM memory or view firmware revision dates press and hold the
Escape
key for 5 seconds. The
following screen appears to show the main firmware revision date and as a prompt for returning the instrument
parameters to default values. Default parameter values are listed in Table 4-1.
Main Code: 03/02/2001
Select With °®
Default Values: No
Use the
VW
keys to select Yes for default values and No to continue without changing the parameter values. Press
Enter
to accept the new selection and continue to the next setting screen. Press
Escape
to cancel the new selection and
return to the normal display.
Operation
4-33
