Keithley 6521, Instruction Manual, Page: 30 / 65

Operation
3-2
CAUTION
Use special caution when using the
Model 6517 voltage source with the
Model 6522. Although the voltage
source has a maximum output voltage
of 1000V, the maximum signal level that
can be switched by the Model 6522 is
200V. It is recommended that you pro-
gram the Model 6517 voltage source
limit to 200V when using the Model
6522. (See paragraphs 3.4 and 3.5 for
details.)
3.2.3 Relay operation
Relays are normally opened and closed when the Model
6517 is programmed to do so, and when scanning is in
progress. Note, however, that all relays will open when Mod-
el 6517 power is turned off.
3.3 Scanner card detection
3.3.1 Power-up detection
The scanner card is detected only at power-on. If the card is
plugged into the Model 6517 after the power is turned on, the
card will not be recognized as being present by the Model
6517.
CAUTION
Plugging in the scanner card with power
turned on may result in damage to both
the Model 6521/22 and the Model 6517
Electrometer. To avoid damage, never
install or remove the scanner card from
the electrometer with the power turned
on.
If the card is not present at power-on, scanner bus commands
or queries will generate a “Missing hardware” error, and at-
tempted front panel operations pertaining to the scanner will
result in messages to inform you that no scanner is present.
3.3.2 Scanner option bus query
*OPT? is an IEEE 488.2 common query which will allow
you determine whether or not the Model 6521/22 card is in-
stalled. The response to this query indicates whether or not
the scanner is present with an appropriate message. Refer to
the Model 6517 User’s manual for more details on using the
*OPT? query.
3.4 Front panel operation
The following paragraphs give an overview of the various
Model 6517 Electrometer menu items used with the scanner
and also discuss opening and closing channels and scanning
operation.
3.4.1 Scanning controls
The following controls are used for scanning:
CARD:
This key accesses the scanning menu (discussed in
paragraph 3.4.2 below) to control most scanning operations.
CONFIG CARD:
Pressing these two keys in succession
will display the card configuration menu. This menu lets you
select current or voltage scanning, settling time, and voltage
source limit.
EXIT:
Pressing this key during a scan sequence will abort
the scan and return the instrument to normal operation.
Function Keys:
As with normal operation, the function keys
control the measurement function to be used during
scanning.
3.4.2 Scan control and configuration menus
To access the scan control menu, simply press the
Model 6517 OPTION CARD key. You can then access the
various levels of the scan control menu, which is outlined in
Table 3-1.
To access the card configuration menu, press CONFIG then
CARD. The card configuration menu is summarized in
Table 3-2.