Limit Test; Overview; Programming Limit Testing - Keithley 6220 Reference Manual

9-2 Limit Test and Digital I/O

Limit test

Overview

As shown in
Limit 1 is used to test whether or not the Model 622x current source is in or out of
compliance. If the source is not in compliance (limit test PASS), all four lines of the
digital I/O port will be low. The Model 622x can be programmed to apply a specific
4-bit fail pattern on the digital I/O lines
source is in compliance (limit test FAIL).
Figure 9-1
Limit 1 test (compliance)

Programming limit testing

The example below shows how to enable limit testing and set a failure pattern of 9
(1001). The FAIL? query is also used to determine if the limit test has passed or
failed.
CALC3:LIM:STAT ON
CALC3:LIM:SOUR2 9
CALC3:LIM:FAIL?
With the above programming, a binary pattern of 1001 will appear on the digital
I/O lines if the limit test fails (source in compliance), and the FAIL? query will
return 1. A binary pattern of 0000 will appear on the digital I/O lines when the
source is not in compliance (limit test passes), and the FAIL? query will return a 0.
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Figure 9-1, there is one limit test that can be performed on a DUT.
Return to Section 9 topics
Model 6220/6221 Reference Manual
("Digital I/O connector," on page
Limit 1 Test
(Compliance)
' Enable limit test.
' Set fail pattern to 9 (1001).
' Query pass/fail of limit test.
9-5) if the