Keithley 199 Instruction Manual page 56

1. Because of the rapid scan sequence in the scan mode,
it is recommended that thii mode be used with data
store. as discussed in oarazrauh 2.11.11.
2. The unit will displa; thi "TRIGGER OVERRUN"
message if it is still processing a reading from a previous
trigger.
2.11.10 Using Data Store with the Scanner
The data store feature of the Model 199 can be used with
the scanner to store data for later recall. For short inter-
vals in the STEP mode, and for the SCAN mode, using
data store is the recommended method of operation
because of the rapid scanning rates possible with the
Model 199.
Scanning at Programmed Intervals
1. Select the range and function as required.
2. Press SHIFT TRIG SFIZIP, and program the con-
tinuous trigger mode.
3. Press NEXT twice to advance to the interval selection
menu. Use uprange or downrange as necessary to
select interval, then press NEXT
4. With select interval, use the data entry keys to program
the storage interval in the range of 25msec to
999.999sec. Keep in mind that the unit will store one
channel per interval in the STEP mode, and one set
of channels per interval in the SCAN mode.
5. Press NEXT to return to normal display after selecting
the interval.
6. Press SHIFT SCAN
SETUP, and program the pole
mode as required.
7. Press NEXT to advance to the scan mode display. Use
uprange or downrange to select the STEP (one chan-
nel per interval) or SCAN (one set of channels per in-
terval) mode.
8. Press NEXT to pro~gram ratio and to rehnn to normal
display.
9. Press SCANNER, and program the desired channel
limit. Scanning will begin at this point.
10. When the unit returns to normal display, press SHlPT
STORE. Key in the desired number of readings to store.
When storing data, the number of readings is equal
to the number of channels per scan times the number
of scan sequences desired. For ewmple, if you desire
to scan all eight channels with a total of 10 scan se-
quences, the data store size would be 80.
11. Press NEXT once the desired data store size has been
selected. The !5TO indicator will flash on to show the
unit is waiting for trigper. Scanning will also cease at
this point.
12. Press TRIGGER (or apply an external trigger pulse) to
initiate scanning at cahnnel 1 and storage. For the STEF
mode, one channel. per interval will be scanned and
stored, while in the SCAN mode, one set of channels
per trigger will be scanned and stored.
X3. Press any function button to cancel data store. Scan-
ning can be cancelled by programming a channel limit
of 0.
14. Data can be recalled during or after storage as dis-
cussed below. RCL will flash when all locations are fu!J
(exe@ in wrap-around mode).
One-Shot
Trigger Data Store Scanning
Use the procedure below to trigger scanned data into data
store. In the STEP mode, one channel per trigger will be
scanned and stored, while in the SCAN mode, one set of
channels per trigger will be scanned and stored.
1. Select the range and function as required.
2. Use TRlG SETUP to program the one-shot trigger mode.
3. Using SCAN SETUP, program the pole mode as re-
quired. Also select the STE? or SCAN modes under the
SCAN SETUP menu. Return to normal display once all
scanner setup programming has been completed.
4. Using the SCANNER button, progmm the desired
channel limit.
5. Press SHIFT store, atid then progmm the desired data
store size in readings. The number of readings equals
the number channels per scan sequence times the
number of scan,sequences. For example, if the channel
limit is 4, the data store size would be 32 with eight scan
sequences.
6. Press NEXT to exit the data store programming mode.
The ST0 indicator will flash on to indicate the unit is
waiting for a trigger.
~iJ Press TRIGGER to initiate the scan/storage sequence.
One trigger per channel (STEP) or set of channels
(SCAN) will be required to complete the sequence.
When all readings have been taken, the RCL indicator
Will start flashing.
8. Program a limit of 0 to exit the scan sequence. The data
can be recalled as outlined below.
Recalling Scanned Data
To recall scanner data from data store, simply press SHIFT
RECALL to enter the recall mode. Press NEXT to view the
last location, or key in the desired location number and
then press~ the NEXT key to display the data, which will
also include the channel number in addition to the func-
tion (except for ratio on channels 2 through 8 which
displays ratio not function). Use uprange or downrange
to scroll through locations, as required. You can exit the
recall mode by pressing NEXT while scanned data is
displayed.