Keithley 6512, Instruction Manual

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E-1
E.1 Introduction
The Model 6512 Electrometer is very similar to the Model
617 Electrometer/Source. The main difference between the
two units is that Model 617 has a built-in voltage source,
while the Model 6512 of course does not. This appendix out-
lines key differences in programming commands between
the two units for those who wish to substitute a Model 6512
for a Model 617 in a system application and make the neces-
sary changes to their programs.
E.2 Omitted device-dependent commands
Table E-1 summarizes those commands included in the
Model 617 that are not present in the Model 6512. All these
commands are related in one way or another to the Model
617 voltage source.
Table E-1
Model 617 commands not used by Model 6512
Command Description
B4
D
F5
0
V Voltage source reading mode
Display mode
V/I ohms
Voltage source operate
Voltage source value
E.3 Status word prefixes
The U0, U1, and U2 status words (paragraph 3.2.13) include
a model number prefix that identifies the instrument. The
Model 617 includes a three-character prefix (617), while the
Model 6512 has a four-character prefix (6512). If your cur-
rent parsing routines expect a specific string length to identi-
fy bit positions, you will have to make program adjustments
to accommodate the new string lengths.
One simple way to accommodate this change is to strip the
Model 6512 status word string of its first character, thereby
reducing the string length to that of the Model 617. For ex-
ample, assume that you are using BASIC, and that the status
word resides in a string variable called
Status$
. The fol-
lowing simple statement will truncate the status word string
to the same length as the Model 617 string:
Status$ = RIGHT$(Status$,LEN(Status$)-1)
Note that the first character (6) of the string will be omitted,
and the new prefix will read 512. The status word bit posi-
tions will then appear in the same relative positions as those
in the corresponding Model 617 status word.
E.4 Status word bit positions
Several status word bit positions associated with the Model
617 voltage source are not used by the Model 6512. These
bits positions are always set to 0 in the Model 6512.
E
Model 617/6512
Software Compatibility