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2600S-901-01 Rev. C / January 2008
Section 12: Instrument Control Library
Series 2600 System SourceMeter® Instruments Reference Manual
status function and attributes
The following provides a brief overview of the status model. Details on the status model are
provided in
of this manual.
Status register sets
A typical status register set is made up of a condition register, an event register and an event
enable register (many also have negative and positive transition registers). A condition register is
a read-only register that constantly updates to reflect the present operating conditions of the
instrument. When an event occurs, the appropriate event register bit sets to 1. The bit remains
latched to 1 until the register is reset. When an event register bit is set and its corresponding
enable bit is set (as programmed by the user), the output (summary) of the register will set to 1,
which in turn sets another bit in a lower-level register, and ultimately sets the summary bit of the
Status Byte Register.
Negative and positive transition registers
•
Negative-transition register (NTR)
– When a bit in an NTR register is set by the user, the
corresponding bit in the event register will set when the corresponding bit in the condition
register transitions from 1 to 0.
•
Positive-transition register (PTR)
– When a bit in a PTR register is set by the user, the
corresponding bit in the event register will set when the corresponding bit in the condition
register transitions from 0 to 1.
Status byte and SRQ
The Status Byte Register receives the summary bits of the five status register sets and two
queues. The register sets and queues monitor the various instrument events. When an enabled
event occurs, it sets a summary bit in the Status Byte Register. When a summary bit of the Status
Byte is set and its corresponding enable bit is set (as programmed by the user), the RQS/MSS bit
will set to indicate that an SRQ has occurred, and the GPIB SRQ line will be asserted.
smuX.source.rangeY
X = SMU channel (a or b)
Y = SMU measure function (v or i)
where v = voltage, i = current
Attribute
Source range.
Usage
rangeval
= smuX.source.
rangeY
-- Reads source range.
smuX.source.
rangeY
=
rangeval
-- Writes source range.
rangeval
The expected voltage or current to be sourced.
Remarks
• Reading this attribute returns the positive full-scale value of the source range the SMU is
currently using.
Assigning to this attribute sets the SMU on a fixed range large
enough to source the given value. The instrument will select the best range for
sourcing a value of
rangeval
.
•
smuX.source.rangeX
is primarily intended to eliminate the time required by the
automatic range selection performed by a sourcing instrument. Because selecting a
fixed range will prevent auto-ranging, an over-range condition can occur, for
example, sourcing 10.0V on the Model 2601/2602 6.0V range, or sourcing 5.0V on
the Model 2611/2612/2635/2636 2.0V range.
Details
See “
” in
Also see
Example
Selects 1V source range for Model 2601/2602 SMU A:
smua.source.rangev = 1
