Keithley 199 Instruction Manual page 44

BASIC DMM OPERATION
NOTE
2.10 DATA STORE
Triggering the unit while it is processing a reading
from a previous trigger will cause a 'TRIGGER
ow3Ruw.
Data Store cant store ups to 500 readings for later recall. Data
can be stored at specified intervals of between l5msec and
999.999sec with lrnsec increments.
In
addition, one-shot
external or front panel triggering can be used to store data
at user-defined rates.
2.9.2 Meter Complete
The Model 199
has
an available output pulse that can be
used to trigger other instrumentation. A single lTL-
compatible negative-going pulse (see Figure 2-9) ~Wi ap:~
pear at the METER COMPLETE OUTPUT jack each time
the instrument completes a reading. To use the voltmeter
complete output, proceed as follows:
1. Connect the Model 199 to the instrument to be triggered
with a suitable shielded cable. Use a standard BNC~con-
nectar to make the connection to the Model 199.
WARNING
Do not exceed 30V between the METER COM-
PLETE
common (outer ring) and chassis
gmund to avoid a shock hazard and possible in-
strument damage.
2. Select the desired function, range, trigger mode, and
other operating parameters, as desired.
3. In a continuous trigger mode, the instrument will out-
put pulses at the conversion rate; each pulse will occur
after the Model 199 has completed a conversion.
4. In a one-shot trigger mode, the Model 199 will output
a pulse once each time it completes a reading after be-
ing triggered,
Reading
DOW
Begin Next
Conversion
zJ i
I t
10p-b
Minimum
Figure 2-9. Meter Complete Pulse Specifications
The following paragraphs describe front panel operating
procedures for storing and recalling data.
2.10.1 Storing Data at Programmed Intervals
Use the following procedure for storing data at defined
intervals.
1. Select the function and range to be used to make
measurements.
2. Press SHIFT TRIG SETUP and verify that the con-
tinuous trigger mode is selected as follows:
CONTINUOUS
3. If necessary, press uprange or downrange to selea the
continuous trigger mode, then press NEXT and set the
trifzzer delav to the desired value.
4. Pr& NEXT: then use upmnge or downrange to choose
"SELECT OFF" (l75msec) OY "SELECT ON" (user-
programmed) data store interval, then press NEXT.
5. For select interval oniy, enter the desired data storage
interval in the range of l5msec to 999.999sec. For e%
ample, to enter a one-second interval, press: 0 0 10 0
0, then press NFXT to complete interval programming.
6. Press SHIFT STORE to enter data store mode. The in-
strument will display the programmed data store size:
000 SIZE
The size value determines how many readings will be
stored (up to a maximum of 500) before the storage cycle
stops. However, a size of Ooo indicates that the storage cycle
will continue even after all 500 readings are stored. After,
the 500th reading is stored, readings will be stored begin-
ning at the fit memory location, overwriting the previous-
ly stored data.
7. Key in the desired number of readings (use 000 for wrap
around storage), then press the NEXT key to program
that value. ST0 will flash on to indicate the unit is
waiting for a tripger;
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