D DDC Emulation Commands
Figure D-1 U0 Status word .................................................................... D-10
Figure D-2 U1 Status word .................................................................... D-11
Figure D-3 U2 Status word .................................................................... D-12
Figure D-4 Status byte format ............................................................... D-14
F IEEE-488 Bus Overview
Figure F-1 IEEE-488 bus configuration ................................................... F-4
Figure F-2 IEEE-488 handshake sequence .............................................. F-6
G IEEE-488 and SCPI Conformance Information
Figure G-1 IEEE-488 handshake sequence ............................................. G-6
Figure G-2 Program example .................................................................. G-8
I Applications Guide
Figure I-1 Guarding to reduce leakage currents ...................................... I-3
Figure I-2 Voltage burden considerations ................................................ I-5
Figure I-3 Simplified model of a feedback picoammeter ........................ I-6
Figure I-4 Electrostatic coupling ............................................................. I-8
Figure I-5 Shielding a high impedance device ........................................ I-9
Figure I-6 Electrostatic shielding ............................................................. I-9
Figure I-7 Connecting the HI terminal (picoammeter)
to high resistance .................................................................. I-10
Figure I-8 Proper connection ................................................................. I-11
Figure I-9 Improper connection ............................................................. I-12
Figure I-10 Range change voltage transients ........................................... I-13
Figure I-11 Transient Voltage .................................................................. I-14
Figure I-12 Down-range voltage transients ............................................. I-15
Figure I-13 Zero check transient ............................................................. I-17
Figure I-14 Connections; diode leakage current test ............................... I-18
Figure I-15 Connections; capacitor leakage current test .......................... I-19
Figure I-16 Measuring High Resistance Using the 6485 ......................... I-20
Figure I-17 Overload Protection Circuit for 6485 Picoammeter ............. I-20
Figure I-18 Connections; cable insulation resistance test ........................ I-21
Figure I-19 Connections; surface insulation resistance test ..................... I-22
Figure I-20 General photo diode leakage ................................................. I-23
Figure I-21 PIN photo diode leakage ....................................................... I-24
Figure I-22 Avalanche photo diode leakage ............................................ I-24
Figure I-23 Basic connection scheme ...................................................... I-25
Figure I-24 Focused Ion Beam signal connections .................................. I-26