Keithley 2000, User Manual, Page: 76 / 280

Scan operations
The Model 2000 can be used with an internal scanner card (Model 2000 SCAN or 2001-TCS-
CAN) or with external scanner cards installed in switching mainframes such as the Models 707, 7001,
and 7002. The following paragraphs discuss various aspects of using scanning with the Model 2000.
Connection precautions
WARNINGS Connection information for scanner cards is intended for qualified service
personnel. Do not attempt to connect the DUT or external circuitry to a
scanner card unless qualified to do so.
To prevent electric shock that could result in serious injury or death, adhere
to the following safety precautions:
• Before making or breaking connections to the scanner card, make
sure the Model 2000 power is turned off and power is removed from
all external circuitry.
• Do not connect signals that will exceed the maximum specifications of
the scanner card.
If both the front panel terminals and the scanner card terminals are con-
nected at the same time, the maximum signal ratings of the front panel ter-
minals are reduced to the maximum signal ratings of the scanner card.
As described in the International Electrotechnical Commission (IEC) Stan-
dard IEC 664, scanner cards are Installation Category I and must not be
connected to mains.
Scanning overview
A scanner lets you switch among a number of input signals to the Model 2000 for measure-
ment. The channel control and scanning capabilities depend on whether an internal or external
card is being used, as well as on the capabilities of the scanner card. Refer to the documentation
supplied with the scanner card for specific connection information.
Using an internal scanner card
The optional Model 2000-SCAN scanner card lets you step through or scan up to ten 2-pole
channels or five 4-pole channels.
The optional Model 2001-TCSCAN Thermocouple/General Purpose Scanner Card lets you
multiplex one of nine 2-pole or one of four 4-pole analog signals into the Model 2000, and/or
any combination of 2- or 4-pole analog signals.
Using external scanner cards
When using external channels, the switching mainframe controls the opening and closing of
individual channels. To synchronize Model 2000 measurements with external channel closures,
connect the Trigger Link lines of the multimeter and switching mainframe. Refer to “Trigger op-
erations” earlier in this section for details and an example on using external triggering.
3-22 Measurement Options