Keithley 6482 - Types of Limits; Pass or Fail Information; Data Flow; Limit Test Feeds

10-2 Return to Section Topics 6482-901-01 Rev. A / August 2012
Section 10: Limit Testing Model 6482 Dual-Channel Picoammeter / Voltage Source Reference Manual
Types of limits
There are six limit tests that can be performed on a DUT.
• Limit 1: channel 1 hardware limit (compliance) test.
• Limit 2: channel 2 hardware limit (compliance) test.
• Limits 3 to 6: software limits for channel 1, channel 2, ratio, and delta.
A test is only performed if it is enabled; you can perform one, two, or all six tests. The tests are
always performed in the order shown in Figure 10-1.
Figure 10-1
Limit tests
Pass or fail information
Pass or fail information for limit tests can be obtained as follows:
• A PASS or FAIL indication on the front panel display.
• With the :CALCulate7:LIMit<n>:FAIL? query over a remote interface, where <n> is the limit
test number (Section 16, “CALCulate7”).
• By reading various status bits (Section 13, “Status Structure,” and Section 16, “FORMat
subsystem”).
• By noting a P or F preceding buffer location numbers (Section 6, “Buffer location number”).
Data flow
All limit tests are part of the CALC7 data block. See Appendix B for an overview on how limit
testing fits into the overall data flow through the Model 6482.
Limit test feeds
You can use the following feeds (data sources) for the software limit tests (Limit 3 to Limit 6):
MSR1, MSR2, RATIO, and DELTA. See “Configuring and performing limit tests” on page 10-5 for
more information..
Pass
LO
HI
Pass or fail on compliance
Pass
LO
HI
Limit 1 or limit 2 test
(compliance)
Limit 3 test
(coarse limits)
Limit 4-6 tests
(fine limits)
Limit Limit
Limit Limit
Fail
Fail
Fail
Fail