Keithley 199 Instruction Manual page 40

BASIC DMM OPERATION
2.7.4 Line Frequency
The programmed line frequency should match that of the
power line voltage in order for the instrume~nt to meet its
noise specifications at 5%-d@ resolution (line cycle in-
tegration is used at~S%-digit resolution). The line frequency
program can be used to check the programmed line fre-
quency and set it to 50 or 60Hz.
Proceed as follows in order to check or set the line
frequency:
1. Press SHIFI DMM SETUP and then NEXT repeatedly
until the line frequency message is displayed. For 6OHz,
the display will show:
FREQ=60Hz
2. For 50Hz, the display message is:
FREQ=50Hz
3. Use uprange or downrange to toggle to the desired @e-
quency, then press_NEXT to go on to the next program.
NOTES:
1. To change the default frequency setting, ftist select the
desired frequency and then use the save setup program
(or send Ll over the bus) to save the new frequency set-
ting. Cycling power, or sending SDC, DCL, or L1, over
the bus will not affect the programmed line frequency.
2. Jf the line frequency is changed but not saved with the
save setup progmm, sending SDC or DCL over the bus
will return the line frequency to the default setting.
However, the reset program will not have any effect orI
the current frequency setting, and sending LO over the
bus will not change the setting, but will save the new
frequency.
3. An "UNCAL!' error will default the IEEE-488 primary
address to 26 and set the line frequency to 6OHz.
2.7.5 Save Setup
The save setup program allows you to save current instru-
ment conditions. These conditions will then be assumed
upon power up, or after the instrument receives the DCL
or SDC command over the IEEE-488 bus.
The following operating parameters are saved by this
program:
Function
Range
Resolution
Zero state (on/off)
Filter state (on/off)
AC dB state (onioffl
Multiplexer (on/off)
Trigger delay
Reading interval
IEEE488 primary address
Line frequency (50 or 60Hz)
In order to save an instrument setup, proceed as follows:
1. Setup instrument operating conditions as desired, or use
the reset program (paragraph 2.78) to save default
operating conditions.
2. Press SHIFT DMM SETUP and then NEXT until the
following message appears:
SAVE NO
3. Use uprange or downrange to toggle to the following
message:
SAVES YES
4. To'save instrument setup conditions, press NEXT. The
unit will save the op~erating states and then go on to the
next program.
NOTES:
l.To exit the program without changing the previous
default conditions, press NEXT with the "SAVE NO"
message displayed.
2. To return the instrument to the factory power up default
conditions, use the reset program and then save those
conditions using the save setup program.