Keithley 2002, User Manual

Page: 97 / 366

Front Panel Operation
2-80
JN functions:
Note that there are five reference temperature
functions available (JN1-JN5). With the Model 2001-TCS-
CAN, the reference junction must be assigned to channel 1.
Junction types are defined using the CONFIGURE TEM-
PERATURE menu.
NOTE
The JN functions in the internal menu are
intended for use with thermocouple
scanner card (Model 2001-TCSCAN).
The Model 2001-SCAN internal scanner
card is not intended to be used with
thermocouples.
No function (---):
Selecting none (---) effectively removes
that channel from the scan list. When scanning, the instru-
ment will skip any channels that have no function defined.
EXTERNAL-INPUTS
This menu item allows you to select measurement functions
for external scanner cards used with the Model 2002 Multi-
meter. When the EXTERNAL-INPUTS menu item is select-
ed, the instrument will prompt you to enter the number of
channels being used.
Use the cursor and range keys to select the number of chan-
nels (1-80), then press ENTER. Once the number of inputs is
selected, you will be prompted for channel functions.
Briefly, these menu items allow you to select the following:
DEFAULT:
This selection assigns the presently selected
measurement function to all external channels.
CHOOSE-FUNCTION:
This menu item allows you define
functions for each external channel. When selected, you will
be prompted to enter the channel to be programmed. Use the
cursor keys and the range keys to key in the channel and
press ENTER. The instrument will then display the available
functions.
Use the cursor keys to select the desired function, then press
ENTER. Repeat the procedure for every external channel to
be defined.
SAVE-ALT-FCN and RESTORE-ALT-FCN
An ALT (alternate) function is one that cannot be directly ac-
cessed with one of the eight function keys. For example, as-
sume that you select the ACV peak function using CONFIG-
ACV. You can then use SAVE- ALT to assign peak ACV to
the ALT function. Whenever the ALT function is encoun-
tered in the scan list, the instrument will switch to the ACV
peak function for that channel even if the instrument is mea-
suring a different type of ACV (RMS for example).
You can also use the ALT function to store an existing main
function but with a different set of operating parameters. For
example, you could set up a specific set of operating param-
eters for the straight DCV function and a second DCV setup
as the ALT function. This arrangement allows you to specify
changes in virtually any measurement parameter from chan-
nel to channel even if the measurement functions are the
same.
NOTE
Some functions may not be compatible
with certain scanner cards. For example,
you should not use the DCI and ACI func-
tions with the Model 2001-SCAN and
2001-TCSCAN internal scanner cards.
SAVE-ALT-FCN stores the presently selected function and
all its configured settings as the ALT function.
RESTORE-ALT-FCN restores the function that was saved as
the ALT function and all associated settings as if a normal
function change were taking place.
2.11.5 Using CONFIG-SCAN to configure
scanning
The SCAN OPERATION menu allows you to configure the
following scanner aspects:
• Select the internal or external channel list for scanning.
• Enable ratio and delta operation.
Table 2-40 summarizes the SCAN OPERATION menu
structure, which is discussed in more detail in the following
paragraphs. See paragraph 2.3.4 for more information on
menu navigation.
Pressing CONFIG-SCAN will display the SCAN OPERA-
TION menu. These choices select the action the instrument
will take when it is triggered.
INTERNAL
This selection enables scanning with the internal scanner
card. When this selection is chosen, the Model 2002 will
change to the function specified for the first channel and then
close the channel and take a reading. When the next trigger
is received, the instrument will open the present channel,
change to the specified measuring function for the next chan-