Model 2651A High Power System SourceMeter® Instrument Reference Manual
Section 7: Command reference
2651A-901-01 Rev. A / March 2011
7-305
For information about .condition, .enable, .event, .ntr, and .ptr registers, refer to
(on page E-
Enable and transition registers
(on page E-18). The individual bits of this register have the following
meanings:
Bit Value
Description
B0-B7 Not
used
Not applicable.
B8
status.questionable.instrument.smu
X
.CALIBRATION
status.questionable.instrument.smuX.CAL
Set bit indicates that the
calibration constants stored
in nonvolatile memory were
corrupted and could not be
loaded when the
instrument powered up.
Bit B8 decimal value: 256
B9
status.questionable.instrument.smu
X
.UNSTABLE_OUTPUT
status.questionable.instrument.smu
X
.UO
Set bit indicates that an
unstable output condition
was detected.
Bit B9 decimal value: 512
B10-B11 Not
used
Not applicable
B12
status.questionable.instrument.smu
X
.OVER_TEMPERATURE
status.questionable.instrument.smu
X
.OTEMP
Set bit indicates that an
over temperature condition
was detected.
Bit B12 decimal value:
4096
B13-B15 Not
used
Not applicable.
As an example, to set bit B8 of the questionable status SMU A summary enable register, set
status.questionable.instrument.smua.enable =
status.questionable.instrument.smua.CAL
.
In addition to the above constants,
questionableRegister
can be set to the numeric equivalent of the bit to
set. To set more than one bit of the register, set
questionableRegister
to the sum of their decimal weights.
For example, to set bits B8 and B9, set
questionableRegister
to 768 (which is the sum of 256 + 512).
Bit
B7 B6 B5 B4 B3 B2 B1 B0
Binary
value
0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1
Decimal
128 64 32 16 8 4 2 1
Weights (2
7
) (2
6
) (2
5
) (2
4
) (2
3
) (2
2
) (2
1
) (2
0
)
Bit
B15 B14 B13 B12 B11 B10 B9 B8
Binary
value
0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1
Decimal
32,768 16,384 8,192 4,096 2,048 1024 512 256
Weights (2
15
) (2
14
) (2
13
) (2
12
) (2
11
) (2
10
) (2
9
) (2
8
)
Example
questionableRegister =
status.questionable.instrument.smua.CAL +
status.questionable.instrument.smua.UO
status.questionable.instrument.smua.enable =
questionableRegister
Sets bit B8 and bit B9 of the
questionable status SMU A
summary enable register
using constants.
Also see
(on page E-21)