Keithley 3700 series Reference Manual page 340

Section 9: Instrument Control Library (ICL)
status.questionable.*
Attribute
Usage
9-196
Questionable event status register set.
Reads condition, enable, event, NTR and PTR registers:
quesreg = status.questionable.condition
quesreg = status.questionable.enable
quesreg = status.questionable.event
quesreg = status.questionable.ntr
quesreg = status.questionable.ptr
Writes to enable, NTR and PTR registers:
status.questionable.enable = quesreg
status.questionable.ntr = quesreg
status.questionable.ptr = quesreg
Set quesreg to one of the following values:

To clear all bits: 0

To set slot interlocks (B1-B6): status.questionable.n
where n = 2, 4, 8, 16, 32, or 64 (for slots 1 through 6, respectively).

To set DMM (B7): status.questionable.DMM or
status.questionable.128

To set CAL bit (B8): status.questionable.CALIBRATING,
status.questionable.CAL, or status.questionable.256

To set thermal bit (B9-B13): status.questionable.n
where n = 2, 4, 8, 16, 32, or 64 (for slots 1 through 6, respectively).
quesreg can be set to the decimal weight of the bit to be set:
To set bit B8 (CAL), set quesreg to 256 (28).
To set bit B12 (Slot 4 thermal), set quesreg to 4096 (212).
To set bit B13 (Slot 5 thermal), set quesreg to 8192 (213).
To set more than one bit of the register, set quesreg to the sum of their decimal
weights. For example, to set bits B8 and B12, set quesreg to 4352 (256 + 4096).
Series 3700 System Switch/Multimeter Reference Manual
Document Number: 3700S-901-01 Rev. A / August 2007
.condition
.enable
.event
.ntr
.ptr