Keithley 2461 Reference Manual

Model 2461
Interactive SourceMeter® Instrument Reference Manual Section 3:
Functions and features
2461-901-01 A/November 2015 3-103
Timer action overruns
The timer generates an action overrun when it generates a trigger event while a timer delay is still in
progress. Use the status model to monitor for the occurrence of action overruns. For details, see the
Status model (on page C-1).
Using trigger timers with timing blocks
For precise timing or if you need to synchronize timing with other execution blocks or events, you can
use the SCPI or TSP trigger timer commands with trigger model wait blocks and notify blocks. You
can use the trigger timer commands to add small precise delays or to start measurements or to
overcome variable measurement delays. The Model 2461 has 1 to 4 independent timers.
For example, you can use a trigger timer to control the delay between non-sequential blocks. After
creating a trigger timer, you can insert a notify block to start the timer at a specific point in the trigger
model. You could then add a wait block to wait for the timer to expire.
Another example is a measure block that takes a variable amount of time. To ensure a precise time
between measurements, you can create a trigger timer and define it to be a fixed interval that is
longer than the longest possible measurement. Then you can set up the trigger model to include:
• A notify block that starts the trigger timer
• A measure block that makes a measurement
• A wait block that waits for the timer to expire
• A branch counter block that iterates some number of times
Some attributes of trigger timers should not be used with the trigger model. Attributes you should not
set are:
 Count value of 0 (resulting in generation of trigger events indefinitely)
 Delay lists
Remote trigger timer commands
SCPI trigger timer commands:
• :TRIGger:TIMer<n>:CLEar (on page 6-235)
• :TRIGger:TIMer<n>:COUNt (on page 6-236)
• :TRIGger:TIMer<n>:DELay (on page 6-238)
• :TRIGger:TIMer<n>:STARt:FRACtional (on page 6-238)
• :TRIGger:TIMer<n>:STARt:GENerate (on page 6-239)
• :TRIGger:TIMer<n>:STARt:OVERrun? (on page 6-240)
• :TRIGger:TIMer<n>:STARt:SEConds (on page 6-240)
• :TRIGger:TIMer<n>:STARt:STIMulus (on page 6-241)
• :TRIGger:TIMer<n>:STATe (on page 6-242)

Keithley 2461 Specifications

General

Maximum Current	7 A
Power	100 W
Resolution	6.5 digits
Source Measure Unit (SMU)	Yes
DC Voltage	100 V
Maximum Voltage	100 V
Display	5-inch capacitive touchscreen
Connectivity	USB, GPIB
Software	TSP
DC Current	7 A
Current Source Range	0 to 7 A
Voltage Measurement Range	100 mV to 100 V
Current Measurement Range	10 nA to 7 A
Voltage Measurement Resolution	100 nV